Back in the 70's I was a chevy guy then a mopar guy and it always amazed me at how often these ford 302's used to come along and give us such grief by being beaten by them time and time again to the point that I eventually became a ford guy too and still am after all these years. I still like chevies and mopars as well and there's nothing like American iron and just the sound of these engines reving up still excites me no matter which brands they are.
Always just loved the way the old 5.0 sounds. The new one sound beautiful as well but it's different with the four valve I guess kind of like picking between a Stratocaster and a Les Paul guitar both sound good in their own way.
I’m a ford guy now too. Started with f-body’s then went fe390 ford then went corvette and now I own Honda and foxbody. They are fun as hell. A corvette is awesome too but 2 seats sucks. Never got into mopar because the hot rods cost a lot up front.
@@vtecbanger3180 Basically in 1969 the Cleveland head was flowing 275cfm@.600" using canted valves which open towards the center of the bore. The valve sizes were 2.19" and 1.71". With a valve job they do 290cfm@.500" and 310@.600" and with porting and a valve job they do 310cfm@.500" and 335@.600". With extensive chamber and port rework they were able to get the heads to over 350cfm ( Glidden -- look him up ). Basically the head have similar potential to TFSR ported and a little below the Yates. The heads were banned from racing: In this link Drag boss garage discuss all the benefits of the Cleveland architecture. ruclips.net/video/_4l0Fe5anh4/видео.html
What fits ? And what is an easy fit ? If I can find a 351 Cleveland that will fit in my 64 Falcon as a direct bolt in and the headers will also fit ! The Used Cleveland makes the most $ence without reinventing the wheel ! KISS Keep It Simple Stupid !
Very well explained. I’m a strong believer that a motors potential to make power is solely based on its displacement. All other things being equal, the higher motor will win. If you put the right heads/cam in a 351 it’ll rev out to 6500 too. And make more power than the 347. Keep it up. You know your stuff
Yeah, I'm tellin ya that compression is the big factor here. Drop some flat top pistons with new rings into fresh cylinders and that 351w would stomp that 347. It's a fantastic comparison, but let's be real here.
Plus the 351 has dished pistons. That has a considerable hinderance in power(lower compression)! Put flat tops in the 351 and send those 347 guys pouting.
Unless one is constrained by space limitations a 351 is the better choice for an all around performance choice. More torque and horsepower in the everyday useable range all the way up to 6000 RPMs in this example PLUS, big plus, the 351 is much less stressed than the 347 and will be far more durable over the long run.
We were turning 6800 with a stock block. Had an aftermarket rotating assembly, but stock stroke, rod length! Flat top pistons ,aftermarket but stock wrist pin location! Car ran 6.51, once and never over 6.60 1/8 mile, never on gas!! All motor! Build what you want, but a Windsor block will hang in there!!! The heavy crankshaft with those 3" mains scare people, but they hang in there for cheap!!
ZERO difference between the 347 & 351 IF the same parts are used in both. The 347 might even make slightly more HP because of it's 0.030" bigger bore & 0.010" shorter stroke & 100lbs lighter in a car! The difference in this test was new high performance parts in the 347 & a "junkyard" 351.
@@bradgriffith4231 ! The block and crank is the primary difference!! Then there is the rod stroke ratio!! We've ran both!! The rod/ stroke ratio alone is the deciding point!! The only argument is the 3" main bearings, and I can tell you a 351 can run 6900rpm all day long!! Noone believes that it's a 306!! The Windsor is a stronger platform! I recondise your constitutional right to be an idiot!! The 347 is a hand grenade!.A cheap 357 will hold up night after night shooting 125 on it! Ran both! The Windsor will hang in there!! No problem! And you don't have to scream them!
@@markmccarty9793 EVERY real motor builder says rod/stroke ratio is totally irrelevent & Engine Masters proved it when they took their mule & swapped only the rods & pistons. Our ALL MOTOR door slammer has gone 7.96/168 in Phoenix in JUNE with 4,000 ft altitude air density, on race gas with 1 Pro Systems carb. NO HUFFER, NO JUICE, & NO HAIR DRYERS!!! How quick & fast is your slug? You have the "right to be an idiot" MORON! I have a pic of the time slip but can't post pics here anymore! There is virtually ZERO difference between a 347 & a 351 other than deck height & weight when built with the same cam, heads & comp ratio!
True, but not everyone wants to build a 351. I've built a bunch of different Ford engines, 5.0 is more cost efficient. My friends all told me I was crazy for building a Ford 400M, but I had never done one of them, yet I had built probably twelve 351W by that time. I like to be the winning underdog.
Love the 351w’s especially in my Foxbody. The junkyard 351 with the Heads and cam swap with the 750 carb is very impressive gains!!! I don’t have the head and cam swap but I run a RPM intake with a 750 carb. The torque difference between it and the 5.0 is crazy.
The cam will make a huge difference alone, getting a head port job even more, it doesn't take too much and if you open the motor up, you may as well get some flatter pistons and change it over to rollers. Just that and no 302 will compare. Had a basic 351 in my old 88 Mustang back in the late 90s/early 2000s when I was younger and thought it was the fastest car in the world, lol, the torque was crazy. Sold it in 2006 and miss the hell out of it and haven't been able to make room for another since 😭. But the kids have grown up, last one is a teenager now, time is coming
Thanks for the vid! I like both engines. The Windsors are beasts. As always, it depends on your specific demands placed upon your specific engine build. My old 1981 Bronco is going to have different demands placed upon the same powerplant as a 1984 Mustang GT 5.0.
Like the videos. The 351 combo here looks nearly perfect for my 94 f150 build. Lot of other factors near tho, rod stroke ratios!! Think that's a big factor in the curve too. That 9.5 deck height and 5.969 rod makes for a good street motor. After years of watching 347's self distruct I'd never have one tho. Wrist pin in the oil ring land! 7500rpm passes, weak stock blocks, po boys need to build one motor that will stay together. Been awhile but I think 347 rods are 5.4" at best! Just think about a good set of heads on a Dodge 360 with those 6.2" rods! Run forever if you don't spray it to death!
Love your videos, keep them coming. One big difference I did not hear you mention or see in the comments but the 351 Windsor does have a much heavier crank then the 302 that I would imagine robs some horsepower.
Wouldn't we all like to see a comparison test where both engines had the same spec cam, and the same heads. Plus the same compression ratios. That way we could judge the configuration differences on an apples to apples basis.
I'd take the 351 hands down ... more peak torque, and more HP and torque across 80% of the usable power RPM band. "HP sells cars, torque wins races" - Carol Shelby
Don’t do it man!!! Do a 351 stroker. I drove around with a 302 based 331 with afr 185 heads for a year and it just wasn’t fast enough. A 383 or a 393 is just so much more everything. I ended up with a 388 and I love it.
@@genemounceSr consider that a running 351w is cheaper to buy than a 347 rotating assembly. If you are looking for a budget build then stick to a 302 with gt40 heads.
I actually bought this xfi cam from you a few months back. I’m putting it in a low buck 393 stroker for my fairmont wagon. Eagle cast 3.850 crank, stock rods, and 302 pistons. You Xfi cam and air gap intake with Victor jr heads. Shooting to make over 500 streetable horsepower. Fingers crossed.
@Skip R the goal was to make 500 horse with things I had or could get very cheap. I ridge reamed the block myself and dingle ball honed it. I have $570 into the whole rotating assembly. I couldn’t have done a 408 for that cheap. The biggest factor in that was likely reusing the stock rods, but for some reason the 302 pistons are much cheaper than the ones I was going to use for a stock stroke Windsor.
The difference in the weight of the crank, rods, and pistons comes into play, plus adding some more camshaft timing and lift would be easy in the 352! When you've split that 302 block that heavy 351 will still be thumping! Wouldn't waste my time! Been there, done that!!
@@giles-df9yu yep, the only downfall is that heavy crankshaft and its wider. Build a 393? I like budget factor, and the durability of the stock crank/rods!
@@bjsteg79 Ran my 66 Stang around my usual corners one day without a hood and could notice a difference, Hood weighed 75 lbs, put on a glass hood with no hinges and battery in the trunk for some more help too pretty easy .
If my old memory serves, a 351 weighs about 60 lbs more than the 302. the one in this test would weigh less than a stock 221 (about 450) with iron heads and manifold.
@@Airpig My 302 stroker has alum heads, intake, water pump, pullies, brackets, thermostat housing, etc, anything I could make lighter I did. The car is 2450 lbs, so even a small weight addition of 50 lbs nose weight would be a huge difference in handling. Battery in trunk, I even moved the mufflers as far back as possible. One thing I'd notice if I was running a 351W rather than my 332 stroker, other than the nose weight, is the stock 351W block can't rev to 8500 on a regular basis, the way the 302 does.
As always, great vid! I would like to see two things in future videos: 1. How much impact has the ignition system (points, Pertronix (I-III), Duraspark ect). Doe it have an impact and if yes under what conditions. 2. Comparison of exhaust manifolds of a 289 (stock, HiPo, shorty and long headers). This would be awesome!
@@429thunderjet2 but what does better mean? Is it measurable? This is why love these videos so much. Richard shows facts straight from the dyno. No guess work, facts!
very important data. I have 2 347 motors and right now 2 cobra r block 351. I was going g to stroke at least one cobra r motor sport blocks to 427, a lovely number and the other as you noted with afr heads x303 cam with built automatic for street. thank you.
@@maximusvonce1381 You can have all the cubes in the world and it wont help you if you cant feed it. It comes down to where you want to make your power and how mild the combo has to be when doing so. Realistically, they offer heads, cam, and induction that can easily support 600 naturally aspirated horsepowers with off-shelf parts whether your at 347 or 408+ cubes. I just don't see 5.7 liters of engine being the limiting factor when talking about small block fords. Look how fast people go on 300 cubes.
@@maximusvonce1381 "Physics" lol. When your limited in available headflow, cam timing, and induction on a given application, in this case a sbf, the same level of induction needed to feed "XXX" horsepower on a 351w stroker would likely support exactly the same power on a less cubes however it would take more rpms out of the smaller combo. Hence my saying, "it depends on where you want to make the power and how mild it should be when doing so". I dont care how much power your 4XX~ cube stroker makes. Theres guys with 300 cube small blocks averaging more horsepower and torque than you and they shift far past 7200rpms. Its a bit nonsensical to claim bigger is end all be all specifically when talking small block fords lol.
@@maximusvonce1381 I can list and link a handful of 310ci class cars that trap low 10s, high 9s na and shift at 9200rpms. Stock untouched 302 bottom ends have been mid-high tens na for well over a decade. Not trying to take anything from the go big displacement crowd but that isnt at all needed for most peoples power goals. I think it mostly comes down to people trying to make comparable power in a more mild combo. Neither is better than the other.
I'd like to see the same test run with both blocks running the same set up with the same compression. The power would be nearly identical but it would be interesting to see exactly how much difference and the shape of the curve.
If it was same bore and stroke between the two the tall deck would make more power, and it's not because of a better rod to stroke ratio. It would be because any turns in the intake manifolds runners are not as tight, therefore more free flowing compared to the short deck. Case in point is any of the 2 piece EFI intakes. Particularly cylinder 5 on the GT40 family of lower intakes.
GREAT VIDEO RICHARD!!!! I AM CONSIDERING BOTH OPTIONS FOR MY EDSEL. MY MAIN CONCERN IS PARTS AVAILABILTY RIGHT NOW. AND I WANT TO ADD A SUPERCHARGER AS WELL. WITH A MANUAL TRANSMISSION. GREAT VIDEO AND THANKS FOR SHARING!!! I LEARNED SO MUCH.
Great vid! So the big Windsor is bulkier and heavier but it'll crank that power out for a quarter million miles whereas a 347 is lucky to do 50K. Easy choice if it's going in a truck.
I’m glad you mentioned the cost difference at the end. The 347 is pretty much the max on a stock block, with the more expensive stroker rotating assembly already there. A comparable 408 that would cost about the same to build as a 347 would’ve likely bested the 347 everywhere. I’m going 427 right now, and people have questioned why I’m not going 363 instead since I AutoCross and track the car...64 cubic inches is why. It’s hard to make that difference up anywhere else on a NA application where I want good low end power AND some steam at the top.
The short deck SBF with its smaller diameter main journals for this engine size comparison is superior in terms of RPM potential and being lighter and physically smaller is idealized for smaller cars. A 351 based stroker crank makes more sense for the overbuilt Windsor, and more idealized for larger cars and trucks.
A point that I think is important is that two engines with the same cubic inch and one has a shorter stroke that engine has more max performance potential. If you were building a very high horsepower engine with enough cross sectional intake area to support very high rpm the shorter stroke is the one to go with since the mean piston speed will be at a much reasonable FPS speed vs the longer stroke.
IF you take 2 engines with the same displacement, say a 351 with 4" bore & 3.5" stroke, & the other with a 4.125" bore & a 3.25" stroke, the big bore / short stroke engine will make more TQ/HP throughout the entire RPM range. The short stroke reduces "piston speed" & the piston travel in the cylinder is where 95% of the parasitic drag is in a motor. The larger bore also unshrouds the intake valve promoting better airflow / cylinder filling, aside from the fact that one can run larger valves in the larger bore cylinder. EVERY well known engine builder uses the same basic formula. As Reher & Morrison has said, put in the largest piston the architecture will accomodate, then make the stroke whatever is needed to reach the desired displacement, & then use a connecting rod to connect the 2, as rod length has very little to do with total HP output.
What about we take the used 302 pistons left over from the 347 conversion (hopefully forged flat tops), stick them in the 351 with a 3.850 stroke crank with stock 351 rods, make an easy 11:1 and run right the hell away from that 347. :)
Well, you compaired a junk yard bottom end to a build 347ci. One thing you didn't mention, is a 351w stock block, will hold 800hp conservatively, more if built right. 347ci , 302 base will only hold 500-600 ish , one over rev or one too many hard launches on sticky tires and block split/ cracks right down valley. This I've learned this from experience, building theses. In addition, the 347ci made more power up top because of cam duration and higher lift. I would of loved to see both side by side .030 builds 351vs 302, Same cam, same Heads. On Dyno. Cheers, Keep on Dreaming 👌
Good informative video. I'm doing an engine swap into a 1955 T-bird which doesn't have a lot of vertical space to work with, so I'm dealing with - as you mentioned - the fitment consideration. The baby birds are much shallower vertically through the body than the regular full size fords of the day. And it isn't obvious when looking at one of the old T-birds, but that hood scoop is necessary. The air cleaner on the Y-block fits right up inside the scoop with only about an inch of vertical clearance. And I want to be sure I have room for a nice tall, high flow air cleaner on my swapped engine. So after a lot of consideration I'm going with the 347 stroker and not the 351 based engine. Also, the 302 based engine is considerably lighter than the 351 (50 lbs or so), which is important to me as I want to shave as much weight off the front end of the car as possible. Thanks for the good thoughts in the vid.
THE WINDSOR IS A MORE HEAVY DUTY BLOCK CAN TAKE MORE POWER AND MATCHES THE Y BLOCKS SIZE AND YOU DON T NEED A STOKER KIT MORE TORQUE WITH LONGER RUNNERS
Never mentioned but these 2 have very different rod/stroke ratios. Great information in these videos as real world tested power shows that displacement + airflow = power. Really puts into perspective where money & effort is best spent.
Rod / Stroke "ratio" has zero to do with total HP produced. Engine Masters has already shown that, as well as showing fuel octane rating makes almost zero difference. Their mule made witin a couple HP on all pulls regardless of octane & required exactly the same 29* ignition timing from 87 all the way to 115 octane race gas.
Honestly there’s a lot of variables. The intake like you mentioned, also the rod ratio and dwell time, the large bearing journal size and rod journal size of the 351 and the weight of the rotating assembly. They’re always going to be close.
A slightly longer rod usually brings higher efficiency, but ran on a dyno there is little difference. This instance, where one rod is half an inch longer, the rod bearing is 3/16" bigger and the crank probably weighs 5lb more, the lighter rotating assembly is going to be worth some power when ran on the dyno at 300r/s.
@@timothybayliss6680 Rod length has zero effect on HP output. Engine Masters did a test & the shorter rods actually made slightly more tq/hp with all else being identical
Good presentation. I was going to expound on a point but he covered it. Meaning "Windsor" style Ford heads and they need that split duration in the cam because they don't breathe....compared to a as built high performance head.
Only way to settle this is to get custom cranks and pistons make in .030" incremements and test with exactly the same cam and heads from a stroke of 3" all the way to 4". Of course to really settle it, you need at least 3 different rod lengths for each bore/stroke combination. I look forward to these tests.
With all else being equal the Bigger motor will always make more power & there's no reason why you'd need different rod lengths, since "compression height" can be changed with the wrist pin location in the piston. I'm running 6" rods in my 409" SBC & the wrist pin is still WELL below the oil ring!
Nah, just have an old 302 block bored and stroked, then throw some inexpensive AFR 185 heads on it. This was my build on a damaged 302 and it cost: $900 for the complete forged piston stroker kit, around $800 for the block work and assembly, $300 for the cam, $1,500 for the heads, and I had good 'ole TMoss port the lower intake for around $300.
@@bradmaas6875 That's $3,800 for a brand-new 347 VS an old 351 that lasts for 100K if you're beating on it. So, no comparison. Try to build a 347 equivelant for $3,800.
@@larrylaverne9547 add a bit more if you don't have an engine to start with. You have two engines, a 302 and a 351. Build them stock or pump them up, the cost will be very similar but the power will not. The 351 will have more HP and torque.
@@bradmaas6875 A 351 block costs more, if you can even find one. Parts cost more, parts are less available, fitment can be a serious problem during and after installation (just TRY to do a simple plug change!) It weighs more... noticably more. I had a Mustang with a 351C, and later, one with a 302 (5.0L) That 351 handled like a fat pig. The understeer was just rediculous. The 302? Felt like a feather, a joy to drive in the mountains. You blow-up a 302/347 block? NP, get another one for $150 or less and do it again.
Big block type power without the weight, actually surprised. With the aluminum heads, intake, use of aluminum water pump and headers I wouldn't be concerned about the weight factor for my truck and the 351W is a stouter block. Will work for my application and save a lot of $$$.
I would really Like to see what the 351 would do with a fresh set of flat top pistons & 30 over for a Fresh bore & a Rebuild to un-Do the diff between raggedy 351 from Junkyard & fresh brand new 30 over 347. My Bro put the Edlebrock top end ( heads & intake, etc ) on an already strong 350 Chevy in a 40 Ford Koop & I could not believe the Diffeerence it made. I believe the Cam is Part of the Head & Intake Kit. That 350 Chevy Sounds Righteous for Sure while it is Pushing You Hard back into the Custom Upholstery on each Shift. PLEASE DO Freshen Up the 351 with Flat Top Pistons & Let us See the Dyno Chart of the Fresh Better Compression 351 Windsor !!
Compression is not a major factor in HP. Hot Rod mag did a test years ago using a 440 Dodge motor because there is no "quench" area in the stock heads. They stacked head gaskets to alter the C/R 1 point at a time & the change made minimal difference & a lot of the difference can be made up by cam duration & valve timing. Low compression needs a little cam to increasse cranking pressure & big compression needs much more cam to relieve cranking pressure.
Displacement difference is negligible, cylinder head design matters as far as inline or twisted wedge, intake runner length, and lobe intensity between the 2 cams will make a difference. The difference in port design was explained by Kasse once you move the intake valve, you can no longer compare stock location valve heads to heads with the intake valve moved based on runner size. MCSA is a lot more important, I’d take the Trick Flow head over Edelbrock any day unless it’s a race head.
The taller deck of the 351 means it has a longer runner length than the short deck 302 based 347. That is why the 351 has more torque all the way to 6000rpm. Shorter runners means higher RPM power, longer runners lower RPM power. The same effect is showing up in the 351 here. So you could use the same heads, cam, and everything else but the longer runners of the 351 will make more torque from idle to 6000. The whole reason the Pontiac engine makes low end grunt like it does is the port length and the shape of the port. They are designed to make all their torque between idle and 5000 rpm. Not that this video is about Pontiac engines, but you can do the displacement test with a 400, 428, and a 455. They can all have the same runner length, head, cam, etc and only the stroke needs to change because those three engines are within .030 of each other on bore and everything except the main journals and piston pin height is essentially the same. Doing that test will show you the difference displacement makes, coming from a 3.75", 4" and 4.21" crank with a 4.15" to 4.18" bore. 500ftlbs is super easy with any of those three engines and a mild cam, and they all can make it from 2500 to 6000rpm with enough airflow. Not so easy to do with a 400 sbc, but the mouse will carry its torque a bit higher in the RPM range due to the shorter ports with a somewhat larger CSA. I've wanted someone to build a 400 sbc with mostly stock parts and compare it to my Pontiac 400 with the same cam timing, compression, both using factory intakes, heads, etc. Nobody wants to do it though. I think it would be fun to find out which one is faster in the same car. Take a 454 and compare it to the 455, you will find less torque everywhere with the 454, but more horse power above 5252 rpm. The ports are larger and shorter, which makes for less velocity at lower RPM, but they can feed the cubes a little better at higher RPM if you can control the heavy valvetrain and actually rev it that high, all else being the same like cam timing single or dual plane etc. Compare the 454 and its 4" stroke to the 428 Pontiac which also has a 4" stroke and the same effect will happen and the Pontiac will make more torque everywhere, but the 428 will make more HP at higher RPM than the 455 will, because the smaller high velocity ports can feed 428 cubes at the higher rpm than they can 455. The 428 can carry the torque a bit higher because its not choked at 5800 by a factory head. Give the heads more airflow and you make more torque everywhere with the Pontiac, and it moves it up in the RPM range on the short runner chevy. A 402 bbc makes more torque everywhere than a 406 sbc. Runner length and cross section is the main difference there, along with valve angles. Engine Masters did that test and that is what they found, the bbc makes more torque everywhere than the sbc at the same displacement. Runner length matters, as does cross section like you said. Port velocity is something you can tune to a certain RPM range using the size and shape of the port, but increasing runner length will almost always result in more torque under 5000rpm.
Back in ‘93 I owned a 90 Mustang LX 5.0L that I wanted a Crawford 347 stroker so badly. But it was cost prohibitive. I was just 22. Ended up spending money on my short block at Nat’s Racing Engines in Seakonk, Ma. Threw on aluminum Edelbrock heads, low compression Paxton VR4 and a little 125HP shot of juice in 3rd gear went 11.7 @124MPH. That was driven easy no powershifting I only had a T5. Always wanted to see what a 347 would have done.
Richard, great job as always! I would like to see you compare a 408 Chevy small block vs a Ford 408 stroker vs a Mopar 408 stroker. Identical components as possible. See who wins!
@@richardholdener1727 Does the 302 sound any different when stroked to a 347 while idling, revving, or at WOT? And also which is safer and more reliable a 500hp NA 302 or a 500hp NA 347?
Having dealt with and built both 347 and 351w there is a major difference in the rotating and reciprocating masses. I.E the factory 351w piston is so much heavier compared to the 1.100" comp ht 347. All that additional weight of conrod and crankshaft takes extra energy to move. I believe if Richard(Bless his good heart) did just a bottom end swap you would see the 347 accelerates faster and makes more power. See if I'm not right. Thanks for the testing
that's an interesting point, because if memory serves, the original 347 strokers used a cut down 351C crankshaft. most modern kits i'm sure are using a specially cast crank. The ability to rev up to say, 6,000 rpm faster with a lighter reciprocating assembly, works on an engine making more power at a higher RPM--a stock 351W head that would fit both short blocks (for example) was designed more for torque at a lower RPM. but that could always be changed with porting and a swap to chevy valves which were larger in diameter. it's worth testing your theory on a dyno. i still think the difference in connecting rod length will cause a piston speed difference, perhaps enough to cause a difference in filling on the intake cycle and exhausting on the exhaust cycle. if so, a different engine family may be needed--or one 351W with super light components versus stock OEM parts.
Enjoy doing things the easy way with off-the -shelf parts while you can. If the environazis at the slimy EPA have their way you will be casting up your own heads and manifolds in a pit dug in your backyard (the way it all started with performance castings) and machining your own camshafts/stroker cranks from a chunk of steel.
Milder 351 stock stroke and rotating assembly basically has the same power as a high dollar, fitment required unit. The moral of the story is, "There is no replacement for displacement.".
@@DarkLinkAD but when you have more qubes with the boost all things equal the larger displacement makes more power. So really boost isnt really a replacement. If everything is equal larger displacement makes more power. Yea smaller displacement with boost can outdo larger displacement but if they both have equal boost larger displacement always comes out on top.
Depends on what your goals are. The 347 is more expensive and typically a weaker block if running a factor block. Stock block safe at 500hp while stock block 351 is good to 750hp with upgraded rods and pistons junk yard 351 is probably $500 while a 347 is about 3500 for short block. Now if you are into foxbodies you will need a different Intake, 351 specific headers and oil pan with drop motor mounts recommended. Now if your car is already stock it really doesn't matter because you will need to upgrade these supporting mods anyway. Now if you already have headers, upgrade Intake, oil pan and motor mounts I suggest just upgrading to a dart block if you are already paying for a forged rotating assembly and machine work. Plus you can leave your current engine in the car while building out your new setup and continue to enjoy your car. I believe stock block 347 cost about $3500 and capable of a safe 500hp while 363 dart block with similar rotating assembly is good to 1200hp. $2000 to more than double your hp capacity is a no Brainer to me. Plus 500hp stock block is one bad tune up away from being a cracked block paper weight.
Or how about direct comparison between Holley efi systems and fitech system have friend with a fitech system but I think its junk needs to b replaced with Holley carb... but would love to see what they both have potential for
Haven't got through all your Vids yet. Curious if you have done any testing on combos for making low RPM torque for rock crawling or towing. Love to see a torque off with the 440, 454 and 460's or stroker variants that could drop into 70's and 80's pickup trucks. Love the videos.
Find a old Edelbrock SP-2P intake 4 barrel,those things make supersonic velocity to the point of supercharging effect. Perfect for trucks turning big tires and crawling. I've seen a 400 Ford turning over 500lb/ft or torque not far off idle running that intake.
The 347 has other "issues" the shorter piston skirt can cause oil control problems and bore wear from the piston rocking more. Plus the 351 has larger bearings that are more suited to low engine speed use. IMHO the more sensible stroker option for 302 blocks would be a 331ci . The wider block and taller deck height also adds weight to the picture so there are pro's and con's to each so it comes down to how much $$ you spend to get the result your chasing.
There is ONLY 0.100" difference in the stroke between a 347 & a 351, which is negligible. The pistons could be almost identical, but the 347 uses a relatively short rod & rod angularity is where "piston rock" could come into play but it would still be a miniscule difference. I run 6" rods in my 409" SBC & the wrist pin is still well below the oil ring & the deck height on ALL small block Chevies is the same, regardless of displacement.
The 347 had a better cam for all out power and that's about it. Swapping the cams would make these motors switch power curves with about 5 more ftlbs of peak torque at 100 fewer rpms and the same peak power but also at 100 fewer rpm for the 351. The tighter lobe separation angle and additional exhaust duration are the critical differences but the headers' primary length and diameter used for these tests could have affected the power curves almost as much.
The 5.96" connecting rod in the Windsor is the best reason to go with the 351w! That, and the fact that the runners are longer equals more low end torque. Besides, the 351 has the ability to take far more power that that the 302 block! The only reason to choose the 8.2 deck block is the 9.5" won't fit!! Ran both, the 9.5 is heads and shoulders above the 8.2"!! The rod stroke ratio on thev347 is horrible!! There's a reason we call them hand granades!! The only drawback to the Windsor is the 3" mains, but it never was a problem for us!!
People talking about a new fresh motor against a junkyard wore out motor being a disadvantage but people forget loose is fast. Thats why they always run best right before it blows
Richard, I’m building a 302 low budget build with parts laying around the machine shop. What realistic hp can I expect with flat tops and e7te heads? Otherwise I have a set of 2v Clevland heads and I was considering building a clevor, however then I need to buy new pistons and an expensive intake.
I went from a 347 stroker to a 408 stroker and the power difference throughout the entire rpm range is significantly more than the 61 ci increase would suggest.
It would have been interesting to run the exact same top end on both engines! Just to see what changes the longer I take runners on the 351w do differently! Imo it’s really hard to compare bottom ends configurations without using the exact same top end combos. Interesting video tho.
I would have guessed the 347 with higher rpm would have had 50 more hp than the 351w.That old junkyard dog has some bite. Love my 351w in my old heavy f150.Shes a old sleeper with a whole lot of bite.
Richard, I would like to see how much power is possible from a 351W using a pair of 100% stock, untouched 1969/1970 351W heads. Find the ideal cam, intake, headers and carb to fully take advantage of those stock heads and find their absolute limit.(on pump gas) 350 hp? more?
As far as I can tell you did nothing wrong. The big reason a lot of builders like the little ford 289/302 is because it's light and small and you can fit it into a lot of small cars: Sunbeams ,Austin healey 3000's and of course the ever classic Ace roadster which eventually became the most awesome Cobra. I love the little engine because of it's fierce reputation for longevity and consider that it was very well designed.
I think packaging in a specific vehicle matters most as in how does it fit in the engine bay. Beyond that though my second thought is how much structural integrity does the 302 block lose when you notch it to fit the modified stroke? Windsor blocks are already known to be kind of weak does the rod clearancing make them weaker?
A stock 351 will def take more power than a built stock block 347. I think its the winner far as bang for the buck. If you're gonna spend money going aftermarket rotating assembly you could just do a 427 windsor with a 351 and really get down.
@@midnight347 definitely. In my situation a 351 won't fit cramming the 302 in was rough. Depending on what your size restrictions are you may have the choice.
Hey Richard, how about some FE testing? I have an old fe390 that's .030 over and begging for me to build it. I'm by far Not a Ford guy but love hp and tq. Want to see if it's worth my time
What would’ve been cool is if he gets a junkyard motor and puts the stock cam and heads on a 347 stroker then we could see what the 351 made stock and 347 stroker With stock stuff
You also have to take into consideration the 351 Is running stock internal so the pistons are gonna be lower compression. The stroker kit is going to come with better pistons , possibly forged even and probably also balanced.
As you said, the smaller engine fits in better when space is tight (say a sleek sports car or race car), and the larger 351W can be bored and stroked to 408 (like that "Clevor 408" in another of your videos). As a Daily Driver that can hold it's own on a track, the extra displacement in the good breathing 408 yields lots of extra torque and HP so I like that combo as Windsor parts are both good and relatively inexpensive. A hardcore racer might prefer the MOD 347 but with just that high end bit from 5700 to 6500 (and a higher REDLINE of about 6750 vs 6250) you have to push it to the MAX to get extra performance edge over the 351W-MOD ...that slight edge would disappear at the 363 and 392 over-bores, and for sure if bored and stroked out to 408. No replacement for displacement, all other things being equal!
So I pretty much want cnc twisted wedge heads with a tight combustion chamber and a cam with decent duration and a tight lsa and an intake to match on a 351w to make some pretty darn decent HP an tq 🤔. I wonder what either would do with the block decked and fly cut Pistons 💪. People only hate on sbf because the e7 heads were such garbage. A well matched hci on even a 302 is not to shabby. Planning on building a sbf for my dad's 68 soon. Now I know what we want!
I was hoping you'd comment on the weight of the rotating assembly between the 351 and the 347. The 351 has a much heavier crank and rods and even longer rods. Which I believe to attribute to the lower speed torque of the 351. I'd like your input on the difference you think the weight had to do with the numbers.
@@richardholdener1727 I know a light weight rotating assembly and flywheel will give quicker throttle response so I figured the opposite would give better torque. Like heavy flywheels being better for truck applications (stored energy). Great videos by the way.👍
@@richardholdener1727 I apologize, I should have been more specific. What I was referring how the two combinations made very similar power but the 351 made its numbers at lower engine speeds. You said that the 351 has longer intake runner is why it probably made power down lower. I'm wondering how much the weight had to do with it also. The crank has 3" mains and the rods are a little more than a half inch longer.
@@brucemallison8350 Tasos who is often working on European cars thinks that a heavier rotating assembly have more momentum and thus make more off idle torque, there are others who think this. Who knows for sure... Oh, in the C63 vs the SLS there is a crank that's 5.5 lb lighter and lighter rods and pistons a C63 built with the SLS rotating assembly gets around 3HP more, it's not noticeable. But lighter pistons and rods equal more high rpm durability.
The tfs 185cc head is actually a bigger head so the 170cc head was a better comparison. With the twisted chamber design, it shortens the intake runner giving it less volume per cross section. The twisted wedge head can't be compared fairly to an inline valve head of the same port volume. After that, there could be a difference in overall weight, which will affect the vehicles performance. Last, there is a subtle difference in pushrod stability with the shorter deck height, but I doubt that will be seen with hydraulic lifters and a modest rpm.
How much difference inn compression and combustion chamber sizing which comp is best same with combustion chambers ???? These videos are great thankyou
Have any tests directly comparing carb size? Like what really happens when you run too small or too big a carb? Maybe the results are similar to what happens when you have “too big of runner” on a small motor. Would be interesting. Like 3-4 carbs on stockish motor and then the same 3-4 carbs on a modified version of that motor.
@@richardholdener1727 do you like them or is it somewhat of a gimmick? I see they stack with the metering blocks. I’m not one that has to change jetting often but it would be fun for tuning purposes... Test and tune or dyno. Thanks again.
Have you done a 347 sbf Vs. 347 sbf??? one with the 3.4 stroke and one with the 3.25 stroke? It would be interesting to me to see this. Everyone always says, "No replacement for displacement" them again, i suppose you did explain that in this video lol
That 351w dyno graph helps me. I am building a 393w with the AFR 185 heads, comp XE282HR, 11:1, with a air gap and a Holley sniper EFI system. I am hoping for 500tq and maybe a little more then 500hp. Its all going into a prerunner F150. Whats your thought Richard? Care to do a dyno session on this engine?
I would still pick the 351 over the 347if I'm going to put that much money on the top end I might as well definitely buy a way better piston for it the 351 so I could have fun longer
Weight and cost difference? I'd expect the mod 351 to be heavier but cheaper. Good showing that .030 bore increase doesn't make up for 0.1 longer stroke and intake runners.
You can put the 347 in more vehicles but you can get a lot more displacement with the 351. The 302 block tops out around 360 CID while the 351W block can get 427 CID. The question is, can a 351W fit into your vehicle without major surgery?
Personality I would go for the 351 in this comparison as a nice street engine in a Fox Body if it would fit. It made more low end torque and in my experience, I never revved a daily driver over 6000. It could also be at home in a 70's or 80's F-250 with a 4" lift and 35's.
It will fit i got a 89 with a 351 Windsor in it fit no problem i had to get a set of i believe it waz 2 inch drop motor mount to make 351 set same as 302.you van use stock motor mounts but I think hood might not shut
Here’s my question, Im building a 347 for my 67 mustang. Problem is finding the right manifold that will produce the best power but will fit under the standard hood. I’m not building a drag engine , I want a street friendly engine. I think I’m using AFR 175cc heads
I notice you could interchange the camshafts, which was not done, and not mentioned. But the cams were compared as being factors. Also, the 347 has a shorter rod which spends less time at the end of the stroke. And the 347 pistons are lighter. In reality though the cams should have been swapped I think. Could have swapped the heads first, then the cams.
Back in the 70's I was a chevy guy then a mopar guy and it always amazed me at how often these ford 302's used to come along and give us such grief by being beaten by them time and time again to the point that I eventually became a ford guy too and still am after all these years. I still like chevies and mopars as well and there's nothing like American iron and just the sound of these engines reving up still excites me no matter which brands they are.
Always just loved the way the old 5.0 sounds. The new one sound beautiful as well but it's different with the four valve I guess kind of like picking between a Stratocaster and a Les Paul guitar both sound good in their own way.
I’m a ford guy now too. Started with f-body’s then went fe390 ford then went corvette and now I own Honda and foxbody. They are fun as hell. A corvette is awesome too but 2 seats sucks. Never got into mopar because the hot rods cost a lot up front.
How did you feel about 4v Cleveland?
@@dennisrobinson8008 don’t know anything about it
@@vtecbanger3180 Basically in 1969 the Cleveland head was flowing 275cfm@.600" using canted valves which open towards the center of the bore. The valve sizes were 2.19" and 1.71". With a valve job they do 290cfm@.500" and 310@.600" and with porting and a valve job they do 310cfm@.500" and 335@.600". With extensive chamber and port rework they were able to get the heads to over 350cfm ( Glidden -- look him up ).
Basically the head have similar potential to TFSR ported and a little below the Yates.
The heads were banned from racing:
In this link Drag boss garage discuss all the benefits of the Cleveland architecture.
ruclips.net/video/_4l0Fe5anh4/видео.html
Stunning results with the 351 Edelbrock package
It comes out to $11 per HP which is amazing value.
What fits ? And what is an easy fit ? If I can find a 351 Cleveland that will fit in my 64 Falcon as a direct bolt in and the headers will also fit ! The Used Cleveland makes the most $ence without reinventing the wheel !
KISS Keep It Simple Stupid !
Love when you do sbf testing
You don't do things wrong , man . You test . I like tests , especially when someone else is doing it 🙃
Very well explained. I’m a strong believer that a motors potential to make power is solely based on its displacement. All other things being equal, the higher motor will win. If you put the right heads/cam in a 351 it’ll rev out to 6500 too. And make more power than the 347. Keep it up. You know your stuff
1 thing not mentioned is the 347 is a fresh motor with 30 over pistons, 351 is junkyard standard bore low compression with who knows how many miles.
Good point
@@janofb 30 over means alot when pistons are flattops and other motor has soap dish pistons. Fresh bore gonna seal things up a bit better also
Yeah, I'm tellin ya that compression is the big factor here. Drop some flat top pistons with new rings into fresh cylinders and that 351w would stomp that 347. It's a fantastic comparison, but let's be real here.
@@paulwhite9020 💪
Plus the 351 has dished pistons. That has a considerable hinderance in power(lower compression)! Put flat tops in the 351 and send those 347 guys pouting.
Unless one is constrained by space limitations a 351 is the better choice for an all around performance choice. More torque and horsepower in the everyday useable range all the way up to 6000 RPMs in this example PLUS, big plus, the 351 is much less stressed than the 347 and will be far more durable over the long run.
We were turning 6800 with a stock block. Had an aftermarket rotating assembly, but stock stroke, rod length! Flat top pistons ,aftermarket but stock wrist pin location! Car ran 6.51, once and never over 6.60 1/8 mile, never on gas!! All motor! Build what you want, but a Windsor block will hang in there!!! The heavy crankshaft with those 3" mains scare people, but they hang in there for cheap!!
ZERO difference between the 347 & 351 IF the same parts are used in both. The 347 might even make slightly more HP because of it's 0.030" bigger bore & 0.010" shorter stroke & 100lbs lighter in a car! The difference in this test was new high performance parts in the 347 & a "junkyard" 351.
@@bradgriffith4231 ! The block and crank is the primary difference!! Then there is the rod stroke ratio!! We've ran both!! The rod/ stroke ratio alone is the deciding point!! The only argument is the 3" main bearings, and I can tell you a 351 can run 6900rpm all day long!! Noone believes that it's a 306!! The Windsor is a stronger platform! I recondise your constitutional right to be an idiot!! The 347 is a hand grenade!.A cheap 357 will hold up night after night shooting 125 on it! Ran both! The Windsor will hang in there!! No problem! And you don't have to scream them!
@@markmccarty9793 EVERY real motor builder says rod/stroke ratio is totally irrelevent & Engine Masters proved it when they took their mule & swapped only the rods & pistons. Our ALL MOTOR door slammer has gone 7.96/168 in Phoenix in JUNE with 4,000 ft altitude air density, on race gas with 1 Pro Systems carb. NO HUFFER, NO JUICE, & NO HAIR DRYERS!!! How quick & fast is your slug? You have the "right to be an idiot" MORON! I have a pic of the time slip but can't post pics here anymore! There is virtually ZERO difference between a 347 & a 351 other than deck height & weight when built with the same cam, heads & comp ratio!
True, but not everyone wants to build a 351. I've built a bunch of different Ford engines, 5.0 is more cost efficient. My friends all told me I was crazy for building a Ford 400M, but I had never done one of them, yet I had built probably twelve 351W by that time. I like to be the winning underdog.
Love the 351w’s especially in my Foxbody. The junkyard 351 with the Heads and cam swap with the 750 carb is very impressive gains!!! I don’t have the head and cam swap but I run a RPM intake with a 750 carb. The torque difference between it and the 5.0 is crazy.
The cam will make a huge difference alone, getting a head port job even more, it doesn't take too much and if you open the motor up, you may as well get some flatter pistons and change it over to rollers. Just that and no 302 will compare. Had a basic 351 in my old 88 Mustang back in the late 90s/early 2000s when I was younger and thought it was the fastest car in the world, lol, the torque was crazy. Sold it in 2006 and miss the hell out of it and haven't been able to make room for another since 😭. But the kids have grown up, last one is a teenager now, time is coming
Thanks for the vid! I like both engines. The Windsors are beasts. As always, it depends on your specific demands placed upon your specific engine build. My old 1981 Bronco is going to have different demands placed upon the same powerplant as a 1984 Mustang GT 5.0.
GREAT VIDEO RICHARD!!!! SOMETHING I AM CONSIDERING FOR THE FUTURE!!!! THANKS FOR SHARING!!!! I LEARNED SO MUCH!!!!
Like the videos. The 351 combo here looks nearly perfect for my 94 f150 build. Lot of other factors near tho, rod stroke ratios!! Think that's a big factor in the curve too. That 9.5 deck height and 5.969 rod makes for a good street motor. After years of watching 347's self distruct I'd never have one tho. Wrist pin in the oil ring land! 7500rpm passes, weak stock blocks, po boys need to build one motor that will stay together. Been awhile but I think 347 rods are 5.4" at best! Just think about a good set of heads on a Dodge 360 with those 6.2" rods! Run forever if you don't spray it to death!
I thought the same thing about the stroke. Dam bro u are the man wish I had ur guided info years ago.lot of respect!
Love your videos, keep them coming. One big difference I did not hear you mention or see in the comments but the 351 Windsor does have a much heavier crank then the 302 that I would imagine robs some horsepower.
Wouldn't we all like to see a comparison test where both engines had the same spec cam, and the same heads. Plus the same compression ratios. That way we could judge the configuration differences on an apples to apples basis.
I'd take the 351 hands down ... more peak torque, and more HP and torque across 80% of the usable power RPM band. "HP sells cars, torque wins races" - Carol Shelby
Sounds Good 2 Me
True, but you'll get a weight penalty with the 351. If you're taking turns and need to stop quickly, less weight the better
The 351W is God's engine. It's what Jesus runs in his fox body.
@@mjcmustang Aluminum block
@@johngregory4801 can get an aluminum 302 as well 🤷♂️
I love your graphical presentations of the results. That is the ONLY way to see any differences. Thanks.
PERFECT timing R.H. ! ! I just sold my LQ4 block/gen4 rods/pistons/317s to build a 347 out of a vintage '68 302 casting block for my '68 coupe ! !
Don’t do it man!!! Do a 351 stroker. I drove around with a 302 based 331 with afr 185 heads for a year and it just wasn’t fast enough. A 383 or a 393 is just so much more everything. I ended up with a 388 and I love it.
@@ivancolesnic I'm just look'n for some motivation for an old crappy car on the 'cheap'. I'd def do a 351w based engine if i had one lay'n around.
@@genemounceSr consider that a running 351w is cheaper to buy than a 347 rotating assembly. If you are looking for a budget build then stick to a 302 with gt40 heads.
@@ivancolesnic ...and a cam, can't forget the cam. LOL
@@genemounceSr only the wrong cam though
I actually bought this xfi cam from you a few months back. I’m putting it in a low buck 393 stroker for my fairmont wagon. Eagle cast 3.850 crank, stock rods, and 302 pistons. You Xfi cam and air gap intake with Victor jr heads. Shooting to make over 500 streetable horsepower. Fingers crossed.
@Skip R the goal was to make 500 horse with things I had or could get very cheap. I ridge reamed the block myself and dingle ball honed it. I have $570 into the whole rotating assembly. I couldn’t have done a 408 for that cheap. The biggest factor in that was likely reusing the stock rods, but for some reason the 302 pistons are much cheaper than the ones I was going to use for a stock stroke Windsor.
You gotta cut on that block too for the crank on the 408. I like the 393 myself, I'm putting one in an 86 f150 4x4 with a 5 speed and 393 gears.
@@northfloridacowboy8728 with stock rods you have to clearance the block near the oil pump and bottom of the bores so the rod bolts clear. Easy peasy
The difference in the weight of the crank, rods, and pistons comes into play, plus adding some more camshaft timing and lift would be easy in the 352! When you've split that 302 block that heavy 351 will still be thumping! Wouldn't waste my time! Been there, done that!!
Correct without the timeing this is "look at this different shade of apples "
@@giles-df9yu yep, the only downfall is that heavy crankshaft and its wider. Build a 393? I like budget factor, and the durability of the stock crank/rods!
One thing I noticed when going from a 351w to a 302w was a very obvious improvement in handling and steering response with the 302w
100 lbs in the nose makes a huge difference
@@bjsteg79 Ran my 66 Stang around my usual corners one day without a hood and could notice a difference, Hood weighed 75 lbs, put on a glass hood with no hinges and battery in the trunk for some more help too pretty easy .
If my old memory serves, a 351 weighs about 60 lbs more than the 302. the one in this test would weigh less than a stock 221 (about 450) with iron heads and manifold.
With aluminum intake and heads the difference isn't at all noticeable.
@@Airpig My 302 stroker has alum heads, intake, water pump, pullies, brackets, thermostat housing, etc, anything I could make lighter I did. The car is 2450 lbs, so even a small weight addition of 50 lbs nose weight would be a huge difference in handling. Battery in trunk, I even moved the mufflers as far back as possible. One thing I'd notice if I was running a 351W rather than my 332 stroker, other than the nose weight, is the stock 351W block can't rev to 8500 on a regular basis, the way the 302 does.
As always, great vid!
I would like to see two things in future videos:
1. How much impact has the ignition system (points, Pertronix (I-III), Duraspark ect). Doe it have an impact and if yes under what conditions.
2. Comparison of exhaust manifolds of a 289 (stock, HiPo, shorty and long headers).
This would be awesome!
@@429thunderjet2 but what does better mean? Is it measurable? This is why love these videos so much. Richard shows facts straight from the dyno. No guess work, facts!
@@429thunderjet2 do you hear us @richardholdener
Great video. Final thoughts are right on target (in my opinion). Keep em coming Richard.
very important data. I have 2 347 motors and right now 2 cobra r block 351. I was going g to stroke at least one cobra r motor sport blocks to 427, a lovely number and the other as you noted with afr heads x303 cam with built automatic for street. thank you.
Yepsir. In conclusion, they both rock.
Stroked Windsor will destroy a built 347. I know cause i have one.
@@maximusvonce1381 You can have all the cubes in the world and it wont help you if you cant feed it. It comes down to where you want to make your power and how mild the combo has to be when doing so. Realistically, they offer heads, cam, and induction that can easily support 600 naturally aspirated horsepowers with off-shelf parts whether your at 347 or 408+ cubes. I just don't see 5.7 liters of engine being the limiting factor when talking about small block fords. Look how fast people go on 300 cubes.
@@madmod Comes down to physics. A bigger motor just as heavily modified will always trumped a smaller one. I spin mine to 7200rpm like a swiss watch.
@@maximusvonce1381 "Physics" lol. When your limited in available headflow, cam timing, and induction on a given application, in this case a sbf, the same level of induction needed to feed "XXX" horsepower on a 351w stroker would likely support exactly the same power on a less cubes however it would take more rpms out of the smaller combo. Hence my saying, "it depends on where you want to make the power and how mild it should be when doing so". I dont care how much power your 4XX~ cube stroker makes. Theres guys with 300 cube small blocks averaging more horsepower and torque than you and they shift far past 7200rpms. Its a bit nonsensical to claim bigger is end all be all specifically when talking small block fords lol.
@@maximusvonce1381 I can list and link a handful of 310ci class cars that trap low 10s, high 9s na and shift at 9200rpms. Stock untouched 302 bottom ends have been mid-high tens na for well over a decade. Not trying to take anything from the go big displacement crowd but that isnt at all needed for most peoples power goals. I think it mostly comes down to people trying to make comparable power in a more mild combo. Neither is better than the other.
I'd like to see the same test run with both blocks running the same set up with the same compression. The power would be nearly identical but it would be interesting to see exactly how much difference and the shape of the curve.
MAKE THE 351 030 OVER
The difference would be miniscule.
If it was same bore and stroke between the two the tall deck would make more power, and it's not because of a better rod to stroke ratio.
It would be because any turns in the intake manifolds runners are not as tight, therefore more free flowing compared to the short deck. Case in point is any of the 2 piece EFI intakes. Particularly cylinder 5 on the GT40 family of lower intakes.
This guy has the best channel on youtube hands down
GREAT VIDEO RICHARD!!!! I AM CONSIDERING BOTH OPTIONS FOR MY EDSEL. MY MAIN CONCERN IS PARTS AVAILABILTY RIGHT NOW. AND I WANT TO ADD A SUPERCHARGER AS WELL. WITH A MANUAL TRANSMISSION. GREAT VIDEO AND THANKS FOR SHARING!!! I LEARNED SO MUCH.
Great vid! So the big Windsor is bulkier and heavier but it'll crank that power out for a quarter million miles whereas a 347 is lucky to do 50K. Easy choice if it's going in a truck.
I’m glad you mentioned the cost difference at the end. The 347 is pretty much the max on a stock block, with the more expensive stroker rotating assembly already there. A comparable 408 that would cost about the same to build as a 347 would’ve likely bested the 347 everywhere. I’m going 427 right now, and people have questioned why I’m not going 363 instead since I AutoCross and track the car...64 cubic inches is why. It’s hard to make that difference up anywhere else on a NA application where I want good low end power AND some steam at the top.
The short deck SBF with its smaller diameter main journals for this engine size comparison is superior in terms of RPM potential and being lighter and physically smaller is idealized for smaller cars. A 351 based stroker crank makes more sense for the overbuilt Windsor, and more idealized for larger cars and trucks.
yeah, I have one, it's a beast a 427" in a 95 Mustang
Theoretically. Holdener says dyno results don't show a noticeable difference between bearing sizes.
Looking to build a 347 for a Sleeper project. This channel is great.
351 with Edelbrock top end package, bang for the buck!!
$11 per HP is a great value.
A point that I think is important is that two engines with the same cubic inch and one has a shorter stroke that engine has more max performance potential. If you were building a very high horsepower engine with enough cross sectional intake area to support very high rpm the shorter stroke is the one to go with since the mean piston speed will be at a much reasonable FPS speed vs the longer stroke.
NOT A CONCERN IN THIS RPM RANGE-VALVETRAIN IS MUCH MORE IMPORTANT
IF you take 2 engines with the same displacement, say a 351 with 4" bore & 3.5" stroke, & the other with a 4.125" bore & a 3.25" stroke, the big bore / short stroke engine will make more TQ/HP throughout the entire RPM range. The short stroke reduces "piston speed" & the piston travel in the cylinder is where 95% of the parasitic drag is in a motor. The larger bore also unshrouds the intake valve promoting better airflow / cylinder filling, aside from the fact that one can run larger valves in the larger bore cylinder. EVERY well known engine builder uses the same basic formula. As Reher & Morrison has said, put in the largest piston the architecture will accomodate, then make the stroke whatever is needed to reach the desired displacement, & then use a connecting rod to connect the 2, as rod length has very little to do with total HP output.
What about we take the used 302 pistons left over from the 347 conversion (hopefully forged flat tops), stick them in the 351 with a 3.850 stroke crank with stock 351 rods, make an easy 11:1 and run right the hell away from that 347. :)
The 387 combination!!
Well, you compaired a junk yard bottom end to a build 347ci.
One thing you didn't mention, is a 351w stock block, will hold 800hp conservatively, more if built right.
347ci , 302 base will only hold 500-600 ish , one over rev or one too many hard launches on sticky tires and block split/ cracks right down valley.
This I've learned this from experience, building theses. In addition, the 347ci made more power up top because of cam duration and higher lift. I would of loved to see both side by side .030 builds 351vs 302,
Same cam, same Heads. On Dyno.
Cheers,
Keep on Dreaming 👌
Good informative video. I'm doing an engine swap into a 1955 T-bird which doesn't have a lot of vertical space to work with, so I'm dealing with - as you mentioned - the fitment consideration. The baby birds are much shallower vertically through the body than the regular full size fords of the day. And it isn't obvious when looking at one of the old T-birds, but that hood scoop is necessary. The air cleaner on the Y-block fits right up inside the scoop with only about an inch of vertical clearance. And I want to be sure I have room for a nice tall, high flow air cleaner on my swapped engine. So after a lot of consideration I'm going with the 347 stroker and not the 351 based engine. Also, the 302 based engine is considerably lighter than the 351 (50 lbs or so), which is important to me as I want to shave as much weight off the front end of the car as possible. Thanks for the good thoughts in the vid.
THE WINDSOR IS A MORE HEAVY DUTY BLOCK CAN TAKE MORE POWER AND MATCHES THE Y BLOCKS SIZE AND YOU DON T NEED A STOKER KIT MORE TORQUE WITH LONGER RUNNERS
Spend the money, get an SHP Block and build a 363 for that T Bird. Power, reliability and longevity. Period.
Never mentioned but these 2 have very different rod/stroke ratios. Great information in these videos as real world tested power shows that displacement + airflow = power. Really puts into perspective where money & effort is best spent.
Rod / Stroke "ratio" has zero to do with total HP produced. Engine Masters has already shown that, as well as showing fuel octane rating makes almost zero difference. Their mule made witin a couple HP on all pulls regardless of octane & required exactly the same 29* ignition timing from 87 all the way to 115 octane race gas.
Honestly there’s a lot of variables. The intake like you mentioned, also the rod ratio and dwell time, the large bearing journal size and rod journal size of the 351 and the weight of the rotating assembly. They’re always going to be close.
A slightly longer rod usually brings higher efficiency, but ran on a dyno there is little difference. This instance, where one rod is half an inch longer, the rod bearing is 3/16" bigger and the crank probably weighs 5lb more, the lighter rotating assembly is going to be worth some power when ran on the dyno at 300r/s.
yes on intake and rotating weight
@@timothybayliss6680 Rod length has zero effect on HP output. Engine Masters did a test & the shorter rods actually made slightly more tq/hp with all else being identical
Good presentation. I was going to expound on a point but he covered it. Meaning "Windsor" style Ford heads and they need that split duration in the cam because they don't breathe....compared to a as built high performance head.
performance heads use split duration cams too
@@richardholdener1727 It depends on the set up, (nitrous)and the Windsor head struggled with exhaust flow, compared to others. Subscribed.
Only way to settle this is to get custom cranks and pistons make in .030" incremements and test with exactly the same cam and heads from a stroke of 3" all the way to 4". Of course to really settle it, you need at least 3 different rod lengths for each bore/stroke combination. I look forward to these tests.
He's basically done rod ratio tests. The power changes primarily with displacement.
With all else being equal the Bigger motor will always make more power & there's no reason why you'd need different rod lengths, since "compression height" can be changed with the wrist pin location in the piston. I'm running 6" rods in my 409" SBC & the wrist pin is still WELL below the oil ring!
After fitment comes cost. Finding a running 347 in the yard is highly unlikely.
Nah, just have an old 302 block bored and stroked, then throw some inexpensive AFR 185 heads on it. This was my build on a damaged 302 and it cost: $900 for the complete forged piston stroker kit, around $800 for the block work and assembly, $300 for the cam, $1,500 for the heads, and I had good 'ole TMoss port the lower intake for around $300.
@@larrylaverne9547 $3,800 vs. $800 for a runner 351. Cost effective.
@@bradmaas6875 That's $3,800 for a brand-new 347 VS an old 351 that lasts for 100K if you're beating on it. So, no comparison. Try to build a 347 equivelant for $3,800.
@@larrylaverne9547 add a bit more if you don't have an engine to start with. You have two engines, a 302 and a 351. Build them stock or pump them up, the cost will be very similar but the power will not. The 351 will have more HP and torque.
@@bradmaas6875 A 351 block costs more, if you can even find one. Parts cost more, parts are less available, fitment can be a serious problem during and after installation (just TRY to do a simple plug change!) It weighs more... noticably more. I had a Mustang with a 351C, and later, one with a 302 (5.0L) That 351 handled like a fat pig. The understeer was just rediculous. The 302? Felt like a feather, a joy to drive in the mountains. You blow-up a 302/347 block? NP, get another one for $150 or less and do it again.
Big block type power without the weight, actually surprised. With the aluminum heads, intake, use of aluminum water pump and headers I wouldn't be concerned about the weight factor for my truck and the 351W is a stouter block. Will work for my application and save a lot of $$$.
The compression ratio is probably the factor.....replace those stock pistons in the 351 with some flat tops and it would be a monster.
I would really Like to see what the 351 would do with a fresh set of flat top pistons & 30 over for a Fresh bore & a Rebuild to un-Do the diff between raggedy 351 from Junkyard & fresh brand new 30 over 347. My Bro put the Edlebrock top end ( heads & intake, etc ) on an already strong 350 Chevy in a 40 Ford Koop & I could not believe the Diffeerence it made. I believe the Cam is Part of the Head & Intake Kit. That 350 Chevy Sounds Righteous for Sure while it is Pushing You Hard back into the Custom Upholstery on each Shift. PLEASE DO Freshen Up the 351 with Flat Top Pistons & Let us See the Dyno Chart of the Fresh Better Compression 351 Windsor !!
Compression is not a major factor in HP. Hot Rod mag did a test years ago using a 440 Dodge motor because there is no "quench" area in the stock heads. They stacked head gaskets to alter the C/R 1 point at a time & the change made minimal difference & a lot of the difference can be made up by cam duration & valve timing. Low compression needs a little cam to increasse cranking pressure & big compression needs much more cam to relieve cranking pressure.
Displacement difference is negligible, cylinder head design matters as far as inline or twisted wedge, intake runner length, and lobe intensity between the 2 cams will make a difference. The difference in port design was explained by Kasse once you move the intake valve, you can no longer compare stock location valve heads to heads with the intake valve moved based on runner size. MCSA is a lot more important, I’d take the Trick Flow head over Edelbrock any day unless it’s a race head.
The taller deck of the 351 means it has a longer runner length than the short deck 302 based 347. That is why the 351 has more torque all the way to 6000rpm. Shorter runners means higher RPM power, longer runners lower RPM power. The same effect is showing up in the 351 here. So you could use the same heads, cam, and everything else but the longer runners of the 351 will make more torque from idle to 6000.
The whole reason the Pontiac engine makes low end grunt like it does is the port length and the shape of the port. They are designed to make all their torque between idle and 5000 rpm. Not that this video is about Pontiac engines, but you can do the displacement test with a 400, 428, and a 455. They can all have the same runner length, head, cam, etc and only the stroke needs to change because those three engines are within .030 of each other on bore and everything except the main journals and piston pin height is essentially the same. Doing that test will show you the difference displacement makes, coming from a 3.75", 4" and 4.21" crank with a 4.15" to 4.18" bore. 500ftlbs is super easy with any of those three engines and a mild cam, and they all can make it from 2500 to 6000rpm with enough airflow. Not so easy to do with a 400 sbc, but the mouse will carry its torque a bit higher in the RPM range due to the shorter ports with a somewhat larger CSA. I've wanted someone to build a 400 sbc with mostly stock parts and compare it to my Pontiac 400 with the same cam timing, compression, both using factory intakes, heads, etc. Nobody wants to do it though. I think it would be fun to find out which one is faster in the same car.
Take a 454 and compare it to the 455, you will find less torque everywhere with the 454, but more horse power above 5252 rpm. The ports are larger and shorter, which makes for less velocity at lower RPM, but they can feed the cubes a little better at higher RPM if you can control the heavy valvetrain and actually rev it that high, all else being the same like cam timing single or dual plane etc. Compare the 454 and its 4" stroke to the 428 Pontiac which also has a 4" stroke and the same effect will happen and the Pontiac will make more torque everywhere, but the 428 will make more HP at higher RPM than the 455 will, because the smaller high velocity ports can feed 428 cubes at the higher rpm than they can 455. The 428 can carry the torque a bit higher because its not choked at 5800 by a factory head. Give the heads more airflow and you make more torque everywhere with the Pontiac, and it moves it up in the RPM range on the short runner chevy.
A 402 bbc makes more torque everywhere than a 406 sbc. Runner length and cross section is the main difference there, along with valve angles. Engine Masters did that test and that is what they found, the bbc makes more torque everywhere than the sbc at the same displacement.
Runner length matters, as does cross section like you said. Port velocity is something you can tune to a certain RPM range using the size and shape of the port, but increasing runner length will almost always result in more torque under 5000rpm.
Damn good reply
5/8 inch runner length difference is insignificant compared to every other parameter.
@@hotrodray6802 it ends up being 1.5"
Back in ‘93 I owned a 90 Mustang LX 5.0L that I wanted a Crawford 347 stroker so badly. But it was cost prohibitive. I was just 22. Ended up spending money on my short block at Nat’s Racing Engines in Seakonk, Ma. Threw on aluminum Edelbrock heads, low compression Paxton VR4 and a little 125HP shot of juice in 3rd gear went 11.7 @124MPH. That was driven easy no powershifting I only had a T5. Always wanted to see what a 347 would have done.
Richard, great job as always! I would like to see you compare a 408 Chevy small block vs a Ford 408 stroker vs a Mopar 408 stroker. Identical components as possible. See who wins!
they all win
@@richardholdener1727 Does the 302 sound any different when stroked to a 347 while idling, revving, or at WOT? And also which is safer and more reliable a 500hp NA 302 or a 500hp NA 347?
Having dealt with and built both 347 and 351w there is a major difference in the rotating and reciprocating masses. I.E the factory 351w piston is so much heavier compared to the 1.100" comp ht 347. All that additional weight of conrod and crankshaft takes extra energy to move. I believe if Richard(Bless his good heart) did just a bottom end swap you would see the 347 accelerates faster and makes more power. See if I'm not right. Thanks for the testing
that's an interesting point, because if memory serves, the original 347 strokers used a cut down 351C crankshaft. most modern kits i'm sure are using a specially cast crank. The ability to rev up to say, 6,000 rpm faster with a lighter reciprocating assembly, works on an engine making more power at a higher RPM--a stock 351W head that would fit both short blocks (for example) was designed more for torque at a lower RPM. but that could always be changed with porting and a swap to chevy valves which were larger in diameter.
it's worth testing your theory on a dyno. i still think the difference in connecting rod length will cause a piston speed difference, perhaps enough to cause a difference in filling on the intake cycle and exhausting on the exhaust cycle. if so, a different engine family may be needed--or one 351W with super light components versus stock OEM parts.
These vids are giving me the itch to pull my 89 notch out of storage.
Enjoy doing things the easy way with off-the -shelf parts while you can. If the environazis at the slimy EPA have their way you will be casting up your own heads and manifolds in a pit dug in your backyard (the way it all started with performance castings) and machining your own camshafts/stroker cranks from a chunk of steel.
Oh heck . I watched again , lol 😆 now I'm confused 😕. Guess I gotta watch it again .
Milder 351 stock stroke and rotating assembly basically has the same power as a high dollar, fitment required unit. The moral of the story is, "There is no replacement for displacement.".
"Except for boost"
@@DarkLinkAD but when you have more qubes with the boost all things equal the larger displacement makes more power. So really boost isnt really a replacement. If everything is equal larger displacement makes more power. Yea smaller displacement with boost can outdo larger displacement but if they both have equal boost larger displacement always comes out on top.
@@midnight347 Its a lot easier make 15psi boost, than to afford a 700cu in 11.4L engine. Far less drag too.
@@DarkLinkAD Yeah, then you "boost" the larger engine, and there goes your exception.
No replacement for cubic $$ MONEY $$!
Depends on what your goals are. The 347 is more expensive and typically a weaker block if running a factor block. Stock block safe at 500hp while stock block 351 is good to 750hp with upgraded rods and pistons junk yard 351 is probably $500 while a 347 is about 3500 for short block. Now if you are into foxbodies you will need a different Intake, 351 specific headers and oil pan with drop motor mounts recommended. Now if your car is already stock it really doesn't matter because you will need to upgrade these supporting mods anyway. Now if you already have headers, upgrade Intake, oil pan and motor mounts I suggest just upgrading to a dart block if you are already paying for a forged rotating assembly and machine work. Plus you can leave your current engine in the car while building out your new setup and continue to enjoy your car. I believe stock block 347 cost about $3500 and capable of a safe 500hp while 363 dart block with similar rotating assembly is good to 1200hp. $2000 to more than double your hp capacity is a no Brainer to me. Plus 500hp stock block is one bad tune up away from being a cracked block paper weight.
Those are the cream of the crop from Ford. 4ci and stroke variants change it identifiably so. WOW 🤩
Good work Richard. Just as i expected between the two engines. And everything you said is true. Mick from australia
Hey Richard,have you ever dynoed the 357w sbf engine?
a .060 over 351w?
@@richardholdener1727yes,
@@docdixon194 He must get so tired of these retarded questions
and these same rules apply across the big three and their respective engines of yesterday. Nice comparison
Or how about direct comparison between Holley efi systems and fitech system have friend with a fitech system but I think its junk needs to b replaced with Holley carb... but would love to see what they both have potential for
More sbf
Ima thinking that the engines would have made near identical power with the same compression ratios. Splitting hairs at that point.
Haven't got through all your Vids yet. Curious if you have done any testing on combos for making low RPM torque for rock crawling or towing. Love to see a torque off with the 440, 454 and 460's or stroker variants that could drop into 70's and 80's pickup trucks.
Love the videos.
Find a old Edelbrock SP-2P intake 4 barrel,those things make supersonic velocity to the point of supercharging effect. Perfect for trucks turning big tires and crawling. I've seen a 400 Ford turning over 500lb/ft or torque not far off idle running that intake.
The 347 has other "issues" the shorter piston skirt can cause oil control problems and bore wear from the piston rocking more. Plus the 351 has larger bearings that are more suited to low engine speed use. IMHO the more sensible stroker option for 302 blocks would be a 331ci .
The wider block and taller deck height also adds weight to the picture so there are pro's and con's to each so it comes down to how much $$ you spend to get the result your chasing.
There is ONLY 0.100" difference in the stroke between a 347 & a 351, which is negligible. The pistons could be almost identical, but the 347 uses a relatively short rod & rod angularity is where "piston rock" could come into play but it would still be a miniscule difference. I run 6" rods in my 409" SBC & the wrist pin is still well below the oil ring & the deck height on ALL small block Chevies is the same, regardless of displacement.
The 347 had a better cam for all out power and that's about it. Swapping the cams would make these motors switch power curves with about 5 more ftlbs of peak torque at 100 fewer rpms and the same peak power but also at 100 fewer rpm for the 351. The tighter lobe separation angle and additional exhaust duration are the critical differences but the headers' primary length and diameter used for these tests could have affected the power curves almost as much.
The 5.96" connecting rod in the Windsor is the best reason to go with the 351w! That, and the fact that the runners are longer equals more low end torque. Besides, the 351 has the ability to take far more power that that the 302 block! The only reason to choose the 8.2 deck block is the 9.5" won't fit!! Ran both, the 9.5 is heads and shoulders above the 8.2"!! The rod stroke ratio on thev347 is horrible!! There's a reason we call them hand granades!! The only drawback to the Windsor is the 3" mains, but it never was a problem for us!!
Well done,what about lighter Bob weight of 347 rotating assembly.
People talking about a new fresh motor against a junkyard wore out motor being a disadvantage but people forget loose is fast. Thats why they always run best right before it blows
Richard, I’m building a 302 low budget build with parts laying around the machine shop. What realistic hp can I expect with flat tops and e7te heads? Otherwise I have a set of 2v Clevland heads and I was considering building a clevor, however then I need to buy new pistons and an expensive intake.
300 hp with a good intake and cam
1 hp per inch
In my experience LSA makes a big difference and the compression
I went from a 347 stroker to a 408 stroker and the power difference throughout the entire rpm range is significantly more than the 61 ci increase would suggest.
It would have been interesting to run the exact same top end on both engines! Just to see what changes the longer I take runners on the 351w do differently!
Imo it’s really hard to compare bottom ends configurations without using the exact same top end combos.
Interesting video tho.
Can you do a lima 2.3 turbo build?
I would have guessed the 347 with higher rpm would have had 50 more hp than the 351w.That old junkyard dog has some bite.
Love my 351w in my old heavy f150.Shes a old sleeper with a whole lot of bite.
Richard, I would like to see how much power is possible from a 351W using a pair of 100% stock, untouched 1969/1970 351W heads. Find the ideal cam, intake, headers and carb to fully take advantage of those stock heads and find their absolute limit.(on pump gas) 350 hp? more?
the limit would be above 350 hp on those heads on a very wild combo
As far as I can tell you did nothing wrong. The big reason a lot of builders like the little ford 289/302 is because it's light and small and you can fit it into a lot of small cars: Sunbeams ,Austin healey 3000's and of course the ever classic Ace roadster which eventually became the most awesome Cobra. I love the little engine because of it's fierce reputation for longevity and consider that it was very well designed.
I ran a 347 stroker against a small block 388 Chevy stroker rear view mirror race the 347 tryed to keep up but no dice but tryed
As for making a 351 fit in a Mustang, there are tubular k members that drop it down so you can use a stock hood.
I think packaging in a specific vehicle matters most as in how does it fit in the engine bay. Beyond that though my second thought is how much structural integrity does the 302 block lose when you notch it to fit the modified stroke? Windsor blocks are already known to be kind of weak does the rod clearancing make them weaker?
A stock 351 will def take more power than a built stock block 347. I think its the winner far as bang for the buck. If you're gonna spend money going aftermarket rotating assembly you could just do a 427 windsor with a 351 and really get down.
@@midnight347 definitely. In my situation a 351 won't fit cramming the 302 in was rough. Depending on what your size restrictions are you may have the choice.
Trickflow 185 has the same size runner volume as the edelbrock but the trick flow runner is shorter. The effective size of the trick flow is larger.
100%. So the 347 not only had shorter runners, but they were bigger.
I'd be interested in seeing the results of a leak down test on both engines.
Hey Richard, how about some FE testing? I have an old fe390 that's .030 over and begging for me to build it. I'm by far Not a Ford guy but love hp and tq. Want to see if it's worth my time
Add a 4.125 or 4.25 stroker kit and good modern heads... 5-600hp easy peasy
What would’ve been cool is if he gets a junkyard motor and puts the stock cam and heads on a 347 stroker then we could see what the 351 made stock and 347 stroker With stock stuff
I have run a stock cam and stock heads on a 347 stroker
@@richardholdener1727 that would be a great comparison to add to the data comparison of these two.
@@richardholdener1727 What did it Run Like? Were The Stock Heads Atleast Decent? Thanks
You also have to take into consideration the 351 Is running stock internal so the pistons are gonna be lower compression. The stroker kit is going to come with better pistons , possibly forged even and probably also balanced.
As you said, the smaller engine fits in better when space is tight (say a sleek sports car or race car), and the larger 351W can be bored and stroked to 408 (like that "Clevor 408" in another of your videos). As a Daily Driver that can hold it's own on a track, the extra displacement in the good breathing 408 yields lots of extra torque and HP so I like that combo as Windsor parts are both good and relatively inexpensive. A hardcore racer might prefer the MOD 347 but with just that high end bit from 5700 to 6500 (and a higher REDLINE of about 6750 vs 6250) you have to push it to the MAX to get extra performance edge over the 351W-MOD ...that slight edge would disappear at the 363 and 392 over-bores, and for sure if bored and stroked out to 408. No replacement for displacement, all other things being equal!
So I pretty much want cnc twisted wedge heads with a tight combustion chamber and a cam with decent duration and a tight lsa and an intake to match on a 351w to make some pretty darn decent HP an tq 🤔. I wonder what either would do with the block decked and fly cut Pistons 💪. People only hate on sbf because the e7 heads were such garbage. A well matched hci on even a 302 is not to shabby. Planning on building a sbf for my dad's 68 soon. Now I know what we want!
I was hoping you'd comment on the weight of the rotating assembly between the 351 and the 347. The 351 has a much heavier crank and rods and even longer rods. Which I believe to attribute to the lower speed torque of the 351. I'd like your input on the difference you think the weight had to do with the numbers.
weight can change power-but not rpm much
@@richardholdener1727 I know a light weight rotating assembly and flywheel will give quicker throttle response so I figured the opposite would give better torque. Like heavy flywheels being better for truck applications (stored energy). Great videos by the way.👍
@@richardholdener1727 I apologize, I should have been more specific. What I was referring how the two combinations made very similar power but the 351 made its numbers at lower engine speeds. You said that the 351 has longer intake runner is why it probably made power down lower. I'm wondering how much the weight had to do with it also. The crank has 3" mains and the rods are a little more than a half inch longer.
@@brucemallison8350 Tasos who is often working on European cars thinks that a heavier rotating assembly have more momentum and thus make more off idle torque, there are others who think this. Who knows for sure...
Oh, in the C63 vs the SLS there is a crank that's 5.5 lb lighter and lighter rods and pistons a C63 built with the SLS rotating assembly gets around 3HP more, it's not noticeable. But lighter pistons and rods equal more high rpm durability.
The tfs 185cc head is actually a bigger head so the 170cc head was a better comparison. With the twisted chamber design, it shortens the intake runner giving it less volume per cross section. The twisted wedge head can't be compared fairly to an inline valve head of the same port volume.
After that, there could be a difference in overall weight, which will affect the vehicles performance.
Last, there is a subtle difference in pushrod stability with the shorter deck height, but I doubt that will be seen with hydraulic lifters and a modest rpm.
that's why I included both
Good explanation between the 2 engines
How much difference inn compression and combustion chamber sizing which comp is best same with combustion chambers ???? These videos are great thankyou
Have any tests directly comparing carb size? Like what really happens when you run too small or too big a carb? Maybe the results are similar to what happens when you have “too big of runner” on a small motor. Would be interesting. Like 3-4 carbs on stockish motor and then the same 3-4 carbs on a modified version of that motor.
Great video! What metering blocks are on that Holley? Thank you!
might be percys adj
@@richardholdener1727 do you like them or is it somewhat of a gimmick? I see they stack with the metering blocks. I’m not one that has to change jetting often but it would be fun for tuning purposes... Test and tune or dyno. Thanks again.
Have you done a 347 sbf Vs. 347 sbf??? one with the 3.4 stroke and one with the 3.25 stroke? It would be interesting to me to see this. Everyone always says, "No replacement for displacement" them again, i suppose you did explain that in this video lol
That 351w dyno graph helps me. I am building a 393w with the AFR 185 heads, comp XE282HR, 11:1, with a air gap and a Holley sniper EFI system. I am hoping for 500tq and maybe a little more then 500hp. Its all going into a prerunner F150. Whats your thought Richard? Care to do a dyno session on this engine?
You need 205 heads minimum. My 438windsor has afr 220 heads
@@maximusvonce1381 so totally not true. I am going for high RPM hp.
A 185 on a damn 393... 🤨
I would still pick the 351 over the 347if I'm going to put that much money on the top end I might as well definitely buy a way better piston for it the 351 so I could have fun longer
347 is max stroke for 5.0 block. 351 has over 400ci potential
@@craigvoclain1406 427 to be exact.
With the LSA of the cams. It affectively lowers the compression ratio on both engines.
A better comparison would be doing the equivalent modifications to the 351 as was done to the 347.
Of course it would but they're about the same if you did put the tw185s on the 351w
🤦🏻♂️
The 347 would be waffle stomped. Especially if you are going to expect durability.
And also consider the costs involved. the junkyard 5.8 was...junkyard priced.
Weight and cost difference? I'd expect the mod 351 to be heavier but cheaper. Good showing that .030 bore increase doesn't make up for 0.1 longer stroke and intake runners.
What about piston to valve clearance with that big of cam!
The 351W is a heck of an engine!
HARD TO BEAT ALL AROUND
Got one in my 1977 searay original engine runs like new never rebuilt well maintained by original owners now the Omc outdrive work in progress lololo
You can put the 347 in more vehicles but you can get a lot more displacement with the 351. The 302 block tops out around 360 CID while the 351W block can get 427 CID. The question is, can a 351W fit into your vehicle without major surgery?
Personality I would go for the 351 in this comparison as a nice street engine in a Fox Body if it would fit. It made more low end torque and in my experience, I never revved a daily driver over 6000.
It could also be at home in a 70's or 80's F-250 with a 4" lift and 35's.
It will fit i got a 89 with a 351 Windsor in it fit no problem i had to get a set of i believe it waz 2 inch drop motor mount to make 351 set same as 302.you van use stock motor mounts but I think hood might not shut
Here’s my question, Im building a 347 for my 67 mustang. Problem is finding the right manifold that will produce the best power but will fit under the standard hood. I’m not building a drag engine , I want a street friendly engine. I think I’m using AFR 175cc heads
stock or performer usually fit
@@richardholdener1727 I have a vintage performer on it now, original 1968 302. Time for an upgrade!? Thanks!
In comparison what are the rod ratio differences between the two?? ,🤔🤓🤷🍻🏁👀
I notice you could interchange the camshafts, which was not done, and not mentioned. But the cams were compared as being factors. Also, the 347 has a shorter rod which spends less time at the end of the stroke. And the 347 pistons are lighter. In reality though the cams should have been swapped I think. Could have swapped the heads first, then the cams.