You might be able to add RPM, but the additional squeeze actually adds lift to the cam. So ultimately that extra half a turn allows more left at the valve to occur and thus will make more power over the curve.
@@davidcarson7542my dad never really explained the theory or reason. He did always say to put a 1/2 to 3/4 turn into them, for our mostly stock race car engines.
Do a set of camshafts with the same lifts but different duration and different LSAs. We all know what they all do but to see a video of them all, that would be neat
David Vizard did that on a 350. With no other changes, closing LSA pumped up torque, widening LSA flattened the curve and improved idle. Duration moved torque up the rev range until heads couldn't flow past 6500rpm. 108 LSA, 252/254 duration high lift cam 1.6 rockers on exhaust side, ported 2.02/1.6 old 186 heads made a killer street engine.
@@marthamryglod291from my understanding David Vizard measures lsa from peak lift to peak lift of the cam lobes. Comp cams measures lsa center to center of the open and close events for each lobe. According to Vizard, displacement picks the lsa, overlap is what changes idle quality and rpm range in his video's that I've watched of his. So in theory from my understanding you could have a something like a 270 duration cam (116 lsa how comp measures it) with asymmetrical lobes that would idle smooth like stock and still have the torque benefits of say a 108 lsa cam as long as the lobe peaks are still at 108. Duration would be determined by your static compression ratio and what you want your dynamic compression to be. I'd love to see a test where someone took 2 cams say something like a 116 lsa cam with the same overlap at 0.050 lift. But one the peaks are at a true 116 lsa how comp measures it and the other with asymmetrical lobes that puts the lobe peaks closer to 108 lsa for a 350 or 106 for a 383. Ironically according to his formula a 110 lsa is the optimum lsa for a 305 so why is basically every comp cam in the catalog ground for a 305 😂😂
15:57 People who work with EFI will have a chuckle at how the crankcase vents in the exhaust stream directly ahead of the oxygen sensor that the Sniper unit is using to read and calculate fuel flows for the unit. Added air "fools" it into thinking the engine is lean and therefor enrichens the mixture.
Yet in reality there is no need to do eo/ic on a stock/mild hft cam as you are far from the lash ramp. Up at 240@50+ on flat tappet or less on roller stuff then yes you need to be doing eo/ic. But there's no harm in educating people to do it this way as it takes the guess work out of it
These guys don't know that -0- lash isn't to make more HP, it's to prevent lifter pump up... they should have done 1/8th turn lash to limit pump up to a minimum...
@@8power857 thats the only way to do it, one up one down. We used to do engine running , back off till they clatter, tighten till they quiet, + qtr. Turn. Just makes a hell of a mess on your fender wells.
@@ronniecox109 its not "the only way to do it" as you say then describe another way to do it 🤦♂️ , there are several ways to obtain correct adjustment. All work if done correctly.
One of the craziest things I've seen: My first car (bought in '76) was a '69 Torino GT, with a fairly worn-out stock 302 2-barrel and 3-speed manual. It would stop pulling at about 5200 rpm, which I attributed to valve float. I was buying up parts to build a serious 289, and had a single four-barrel tunnel ram on hand. I also came across a Holley 465 cfm four-barrel (I think the smallest they made, w/vacuum secondaries, of course) that an acquaintance was selling. So I thought: "Why not?" I was running the 302 HARD, since I was planning on replacing it anyway. So I popped the tunnel ram and Holley onto the otherwise-stock 302. Started EASILY pulling past 6000 rpm, and was otherwise a MAJOR improvement in power from launch on up. Only thing I can think is that it worked so well because the carb was SO SMALL! : )
The stock 302 2v even has push it valve spring studs. So if you want to run high rpm without destroying it, you need to install screw in studs and stronger valve springs.
@@charlesvan13 Need screw-in studs with higher lift cam & higher spring pressure, not just because you rev a stock cam high. You'll experience valve float from the weak stock springs before you pull a stud out
Great video guy's. I have always turned 1/4 turn after zero lash with really good results. People kept telling me go 1/2 turn but understanding hydraulics and design of the lifter it only made sense to me to lightly preload since the lifter was designed to do it's job efficiently.
I love seeing what these parts do with a stock cam and compression to get a base line on small changes. Because sometimes people dont want or dont have the money to get to deep but want there car to be as efficient as it can be. Nice test!
Remember folks, it's not the engine they're comparing, it's the intakes and fuel deliveries. A worn out 305 is good, as long as it's the same worn out 305 with every test.
@@blakake the factory 150-170hp figures are with mild tuning and restrictions on everything. Get rid of all that and yes you can if the engine is still pushing good compression. Where people always go wrong with a 305 is they put way too big of camshafts in them. With the proper camshaft and some Vortec 305 heads you can easily get over 300 horsepower and 300 lb ft of torque. I have done all these things when I was younger so it's not like I'm just talking out of my ass I've been there and done it all. The 305 is not as big of a turd as people make it out to be.
@@blakake Ok I was off a little, just found my old dyno result from my G- body with my 305 and it was laying down 192hp and 244 lbft of torque at the rear wheels.This was with a reworked Q-jet off of a 327 small block, long tube headers, 32 degrees timing and other fuel tuning. The big killer on those factory set ups besides exhaust flow is those ancient computer modules that control the carb- timing ect.Oh I had an aftermarket vaccum advance HEI set up also.Keep in mind those numbers were after drivetrain loss.I was running 100 octane gasoline no ethanol also.
This video came just in time, I am working on a Chevy with a 305 and wasn't that sure about some timing things, so this saved me. You guys are heroes! Greets from Holland.
Just curious, is a chevy pretty common or uncommon over there in Holland? I'll admit to my ignorance being a US boy but just was an interesting thought
@@ryanroberts3742 as a old-timer yes, in the Netherlands Chevy's are very common. Well asking questions is always a good thing, how else will we learn things. But as daily stuff we have a lot of 4 and even 3 cilinder cars (ford, Peugeot, Skoda, VW, etc) because of the high gas prise and emissions rules. I wish we would have more V8 stuff here because we have to import everything we want to do on our V8 old-timer cars.
before you do a cam, i want to see a 1.6 ratio rocker arm swap on just the exhaust valves and then a full all round 1.6 swap. because no one ever tests the stock cams and changing the lift via the rocker. i want to know what everything else really adds compared to a cam swap, cause we all know that a cam ads power
@@kskip4242 but will that actually happen, because if it would, wouldn’t it happen to any cam, sure the 305 has a cam heat treat problem but what about other engines
Didn't some GM engines have plastic coated gear on camshaft? Seems I saw one that the plastic gets crispy and starts coming off on high mileage motors.
Yeah I'm sure it would make way more power with a 650 but the 950 probably has a higher profit margin and on a Dyno with unknown load why not run the biggest most money carb
on my '87 CRX after i rebuilt the engine, I'd put about 3/4 a bottle of seafoam into the gas tank, and the last 1/4 in the oil. ran that several times, doing a full bottle every 3rd gas tank and a 1/4 after every oil change. took a while but it vastly cleaned up all the gunk that was left behind in the rockers and oil passages in the crank/rods and cleaned up the valves really good
Circle track guys may consider "zero lash" by taking out lash altogether and adding washers inside lifter to greatly reduce hydraulic space. Making it act more like a solid lifter. Alot of measuring is done inside lifter bore and the whole job is alot of time taking measurements. It does increase power by a few.
I had always set the lash preload at zero plus 1/4 turn. I always felt that 1/2 was a bit too much. You can hear the engine labor each time you go from 1/4 to 1/2 turn. But zero lash is not enough because you will lose a small amount of lift and duration. Anyway... that is my theory...
@@starfirerider if you are doing 3/4 turn on a GM motor..... you are an idiot LOL . GM valve train is DESIGNED to be zero lash - zero preload that gives you the best lift, duration, wear, friction, and float protection .
zero lash is NOT going to loose any lift.... its a hydraulic lifter!!!!!!!!!...... that 0.0001 lift you are "loosing" is simply taken up by the lifter pumping up . besides... hydraulic lifters will ALWAYS loose a bit of lift over a solid lifter..... again, due to it being HYDRAULIC! . the oil WILL compress a bit.... or leak.... or back flow reducing lift . . . but its SUCH a small amount probably 10HP on a 500HP motor...... . the difference between 500 and 510 (or 490) is NOT going to be felt..... nor will you be able to tell on your 1/4 mile times . . you can easily make up for the ~10hp loss by setting up your car better..... or not eating that large pizza before you put on your race suit
Both are good intakes. Really depends on your combo. My 496 big block makes 550 foot pound of torque at 3,000 rpms with a dart single plane. I could only imagine if I had a rpm air gap intake on it.😜
@@springwoodslasher79 Easy there turbo, he specifically mentioned torque and a low RPM. And it's youtube comment section bench racing speculation, I think it's alright to wonder about an AirGap.
@@springwoodslasher79 you gotta remember though that any BBC is built for low end torque, ESPECIALLY the 496/8.1, most guys with em care about torque, not hp
@@lomfmur the guy im responding to has a 550hp big block v8 so your. 8:1 argument is beyond ignorant. Most guys care about torque not horsepower? Lol 😆 🤣 😂 😹 ... seriously GROW A BRAIN.
i can testify...a semi worn out 305 loves more cam(i used the l-82 vette cam) better heads (i used vortecs) a dual plane (edlebrock rpm ) and a 650 holley...makes for a fun mini mouse.....this engine has maybe 8-8.5 to 1 compression and lives on 87 octane
I'd like to see the test done at 1 full turn the way GM always recommended back in the day. Plus I never made an adjustment on new lifters without pre oiling the engine by using a adapter and a drill to pump up the oil pressure up.
It takes ages but you can actually turn the lifter almost to the bottom of travel. It requires a bit of planning during build up as the pushrods may have to be longer but there are some advantages and you guessed it, some disadvantages. There are some really excellent articles for racers that must run hydraulic OEM style. The rest of us can run short travel lifters and they need to be set exactly as the manufacturer recommends.
1 Full turn can pump up the lifters until the valves hit the pistons at high RPMs with a performance cam... 1 full turn is to avoid ever needing a readjustment on stock cams...
@@BuzzLOLOL so you're an L1 certified Master Tech like me, who has been to GM School. I've done hundreds of engines setting up one full turn on a new set of lifters on a new camshaft. If you're afraid of lifters pumping up go solid lifters like a good old Duntov 30/30 camshaft.
You can basically get any SBC engine to make 1 horsepower per cubic inch and run over 100,000 miles and that includes the 3 V6 variants. So how is the little 305 junk??? The challenge here are you smart enough to make a small engine put out good power and stay together. The money we spend on our junk does not play into it. If you want to talk horsepower per dollar you just go buy a complete engine ready to run, but what fun is in that???
@General Mayhem A good friend of mine put some type of camshaft in a 267 that was in his Chevy Monza and topped it with a Performer intake and a small Holley carb. Even as a teen I found that car was one scary ride. I told my buddy that all the work he was doing wouldn't help much, man was I ever wrong. It would peg the 85 mph speedometer in second gear.
i got a bone stock 305 c. i. worn out weezer with an edelbrock Super Victor II intake popping through the custom hood and 1000 cfm demon carb maxed velocity in a fat tire firebird, runs like hell through the turns dies at yield signs. i need to move up to a dual carb tunnel ram with velocity stacks.
I remember back in the 80's Eddie Bristol would adjust the rockers with the engine running and oil would be going everywhere and he told me and my brother that this is the proper way to do it. 😂
I think they skipped over some things. The sniper system requires a single plane intake or at the very least an open spacer or you will have problems. Also for accurate results you would need to let the system learn between part swaps. The first pull on the system will run well, but it will keep tuning itself. They also did not show any timing adjustments with each swap.
I want you guys to do a single plane va dual plane video like this, but test them on a bunch of different SBCs. I'd like to see how the two intakes affect a 175hp 305cid vs a 325hp 350cid vs a 500hp 383cid. That sounds interesting.
I know this is an old video, BUT it's so cool to see a usd 305 on the dyno!!! Who does that!! :) ... Nice to see stuff we are stuck with in our work trucks??? Up on the Dyno!!
I don’t care what anyone says about the 305, I like them. All the intake manifold test proved, is that the intake isn’t the restriction on the engine. The heads are the restriction. If you do a head shootout you’ll see bigger horsepower gains with the different manifolds
In 1978 I had a 77 Ltd II, 351W. Had cylinder heads, both crack water jackets. Never did dyno but with the Torquer 2, Holly 600, and 74 Torino long tube headers with 24" cherry bombs, a 30mph tromp would break the tires loose. A bonus was going from 15-16mpg at 55-60mph to 20 at 80. Never let a woman drive your car if you plan on keeping it
I prefer a "hot" cam with a single plane intake and a "modest" carb to get a good, high-revving small block. If running a big block, I would go with a dual-plane intake, since they usually don't rev as high and you want that low rpm torque.
Pat just an fyi. Been spinning that pushrod to find zero lash for 40 yrs! Never had a single mishap with this method. Also , every professional engine builder i know does it this way as well. I'm not sure, but i think the way you showed, is how most "in their garage builders " do it.
SO much easier and faster to do this with the engine running. No messing around with base circle, which order to do it in, can get the whole engine done in 2-3 minutes.
Single , Single turbo , Inline V 6 , all wheel drive or I'm a supercharger guy myself ! But , all the philosophies I've ever heard throughout the world really has flew out the window Because of the power nation crew , and Mr . Pat all jokes aside My professor
Basic rule of thumb if you want to produce a lot of torque low down before 1500 RPMs a dual plenum intake is nice if you're planning on racing street strip style and your motor makes more horsepower above 15,000 to 2,000 RPMs a single plane intake is perfect because the RPMs are already up there past 1500 1800 RPMs so you don't have to worry about the full RPM ranges
The zero pre-load for hydraulic lifters was part of the Royal Bobcat tune for 421 Pontiac engines in the GTO in early '60s. Interesting results from your dyno.
Your video did get very close to a full explanation of the heater by pass port. But can you get more detailed like showing the hose connections and showing the exact flow of the heater hose outlet on the water pump to the manifold. Is that from the manifold flowing into the water pump? And the hose coming out of the manifold, can it go to the heater core and back to the radiator too right hole to allow bypass while engine is warming up? Thank. You for your help on this?
Throughout one of my tenures working at a dealership, I attended a GM Good wrench School,, and was always taught on GM V8 engines while the engine is running cold when you first start the engine is when you adjust your valves back it off until it clicks turn it quarter of a turn at a time until it stops and then a half a turn to finish.. and do to that other than the fact of putting an engine together and taking the lash out of the valves on a stand (spinning the pushrod) just to get to a starting point that's the way that I was taught to adjust valves from Mr Goodwrench himself..🤔
I noticed the earlier runs were with alternator and water pump installed for cooling. The current run is with an electric water pump. How much difference in parasitic drag did that make?
I recall another video where they tested alternator makes basically zero difference, it was 1-2hp which is within margin of error imo. There's just not enough resistance in a "reverse electric motor" to make a difference on big engines like these.
It's not a debate.. street engine needs a dual.. if the car has a camshaft that makes power up top and lives its life at 4k -7500 has deeper gears. A loose converter. Start lookin at a single...
I think you guys should add a few more commercials. Ive always tightened the rockers until the pushrod spin just starts to drag then let hydraulic pressure finish the lash. Ive never had a problem during start up, run or race.
bought a two year old 68 Camaro that had a 210 hp 327 two barrel. That thing ran like a beast beating many 350 lemans etc. loved that car. the wife could get mid 20;s gas mileage. Me? not so much. fun video thanks.
I picked up 500 rpm using a small economizer intake with a 302 stock ford engine with a600 holley carb on my airboat. Before 2500 rpm after 3000rpm . With secondary set to open quickly it gave snapper performance from 2000 to 3000 rpm but no more rpm.
I want to see you guys do something over the top cool. Do the best dyno run you can with a flat tappet cam with an .842 lifter and then bush the block for a .904 lifter and see if its way better.
I have a somewhat stock 350 with a mild RV cam I am running a Edelbrock 1701 intake with a 1405 carb! I also have a open plane 1/4 spacer! The reason I ran the spacer is heat issue carb was getting too hot! My question is should I put a dual plane spacer or am I fine with open plane?
Could you guys maybe do a super advance ignition timing study? My little brother made a setup to work off of a choke pull, that we hooked to a rotational plate on the distributor. (He was a machinist/mechanic. While you couldn't start a car at 37 Degrees before TDC, you could start it, and then rotate the distributor, after running. The torque and HP gain was phenomenol. Then again, a few times, I over did it. I was given a Geo Tracker that was painful to even drive. I bumped up the timing, and would squeal the tires both taking off and shifting. After 6 months of enjoyment, I broke the crankshaft between cylinder 2 & 3. OOPS! Please do a video on static timing on a SB Chevy. Thanks
They said they have never pulled the valve covers until after the ran the seafoam. How can they say how good it worked🤦♂️. WTF lol. I guess they will say anything if they are getting paid to.
I would LOVE to see a video testing different styles of pistons. I'm building my 69 c20 and having the motor rebuilt but I've already put in a t56, disc conversion on the back, and a few other little things but I'm planning to build another engine for another build and seeing the pros and cons of different pistons would be helpful. The same about cams
Piston choice is determined by application. N/a boost or nitrous will determine material. Desired Compression and combustion chamber shape affect piston shape. Dome /dish valve relief. Cam choice can also affect piston to valve clearance. There's a bazillion old school chevy builds to use as a guide.
This video gives you a great concept for how well engine components complement each other. The intake it came with and the ones that aren't really matched for it, all make roughly the same power. This tells you that you're essentially at the limit for the heads and cam. The cam just isn't going to open the valves enough or long enough to get any more air through and the heads probably won't flow much more anyway. You can see where the power drops off north of 4500, that she is basically breathing through a straw. Just google and look at the differences in a factory 305 head and the DZ302 heads from the first Z/28. The port sizes, the combustion chamber. Compare the cam specs and look at the duration GM used with the old DZ. Also interesting is that the TPI 305 that GM put in some F-bodies is more powerful from the factory than this Holley equipped van motor. Really shows what performance components can do.
That 950 carb is actually probably hurting power on this motor. When a carb is too big the fuel doesn't get atomized as well and actually hurts power, that's even after the carb has been tuned correctly. I've seen 430 horsepower small black chevys show no gain in power on the dyno once the carb got bigger than 750. Once a 950 was on it, power actually went down everywhere even when it was tuned correctly.
Exactly! 950cfm is out of this world crazy! I built a 381 stroker Chevy with every sweet part I could throw on it (too a point lol). It made 511hp and 492tq. The carb is a 650cfm speed demon. You want the absolute smallest carb on the engine you can get away with. Then jet it what it needs. An engine is an air pump. It can only draw in so much air. That little stock wore out engine needed a 450 or 500 cfm max. Then, jet it right. The bigger the carb absolutely does not mean more fuel, more power. It's the opposite. The smaller the carb, the better the throttle response. It draws a better signal to draw in the right amount of fuel (monitored with the jets). Imagine putting on a 2000 cfm carb. More air and fuel? Nope. With a 2000 cfm carb, the same amount of air will be pumped into the engine, but the boosters and all the rest of the gizmos cannot sense the small amount of air running past the venturies. So if it cannot sense the air, it won't let fuel go into the engine. It'll be a dud, even if you put 1/4" jets in the sucker. My 2 cents. I used to rebuild carbs.
@Common Sense Realist yeah. If I had to do it over again, I would build engine a bit differently now. I'd build a torq monster. I was basically a kid 16 years ago and I was probably going to race it at the strip plus I wanted higher hp numbers. I'd put a high lift cam, regular cam duration and a dual plane intake on it. I'd stick with a 600 or 650 carb tho. Instead, I put edelbrock Victor Jr heads and intake on it. The cam I picked is good for a loppy idle tho 😉
I've read that the tall center divider on some dual planes (like the one in the video) prevents the Sniper's MAP sensor from seeing both sides of the manifold which can lead to incorrect fuel ratios on some cylinders and erratic performance. It's recommended to notch the divider. Can we try that on this motor/manifold?
Where do I find information on auto-repair shops that can do this kind of detail testing in Georgia, for an AMC 258 4.2L in Jeep J10. Thanks for your video
When they switched to the Holly sniper Fuel injection replacing the 950 carb, they were pleased because the engine made a few more horsepower. The problem is that when the engine was running the Carb.it was also running a mechanical water pump and a alternator. When they switched the engines, the mechanical pump had been replaced by a electric water pump and the alternator was gone, that's where the extra horsepower came from not from the injection setup.
@@jasonhooey5677 in what world is 13.1 rich? Most power is being made for most engines at around 12.6-12.8 on my engine dyno. Pump gas has 10% Ethanol, which brings AFR down even more.
@@jasonhooey5677 that is not HP related. I ran a stock 84 Vette TPI on the dyno the other day and it made peak HP at 12.8. When you have tons of overlap then yeah, some fuel flushes out the exhaust and you wanna make it richer. So I 13.1 at WOT is neither rich nor “super rich”, but rather lean. So the direction of that statement is wrong to being with.
Please do horse power increase or decrease with stock exhaust manifolds and headers, colder thermostats, higher ratio rocker arms, heavier valve springs, different spark plugs and wires, additives that promise horse power, lighter fly wheel and clutch assembly
@@crackjack8320 - More likely lost MPG since it lost torque... and the new EFI cars have to spin the engine over twice to start whereas carb. cars start the first time a piston comes up and you don't even hear the starter...
The original intake installed looks like the old old torker sp intake. I would have thought that intake would have really killed bottom and mid range torque, but it didn't. Even with the itty bitty, worn factory cam, with a stretched timing chain.
Howdy P-N, seafoam = "Petroleum Distillate" - why not just # 2 Fuel Oil or DIESEL ? fuel-injection + a single-plane intake ... Dual-Plane & a 600 cfm or 650 cfm Holley would have been more informative - IMHO COOP ...
I pulled the scorpion torquer of the SBC 385 (0.40 over) and put on an RPM air gap dual plane and the thing stomped off the bottom and screamed all the way to 7000 much harder than the old single plane.
I was going to go with an Air gap as well, but my Cam builder ( Mike Jones Camshafts) disagreed and said I would be leaving alot of HP. So a single, port matched, Vic JR has been in it and its an awesome street motor. Plenty of tire roasting TQ on tap, and a killer pull all the way to 6700 - 7000 rpms. Very happy. I do wonder how the airgap would perform though.
@@arodderz My cam is a Howards blower grind PN:110265-14 with Dart IK 200 Heads, Admittedly the old Scorpion single plane torquer is Edelbrock's oldest of that style of manifold, but the difference in bottom end and top end power is chalk and cheese, the power off the bottom is mostly noticed and is like a totally different motor coming out of a corner in second gear (Muncie 4 speed) with 3.36 rear gears just driving normally the tires start squealing just with minor input and it will just go up in smoke as you squeeze the throttle on, the torque delivery is like I bolted a 454 in it. My only complaint is I have to put a scoop on the hood of the Vette.
@@brianross4057 not sure how different the older type of single planes behave or work, but I know some may be to " large " for certain street applications, like the super victor. Glad your set up works for you. 👍. Maybe down the line, when $ become avail, I'll buy the dual and give it a go...i know it will do great
Back in the 1960's the reason we used zero preload was to prevent lifter "pump up" in case of valve float, NOT because we thought it made more power.
that is the ONLY reason for zero lash - zero preload
.
"Uncle Tony's Garage" just did a video about this
I was always told to do this to make the lifter behave like it was solid and you can squeeze some RPM out of it.
@@kainhall I would never take advice frm that idiot "uncle Tony" the guy is a total tool
You might be able to add RPM, but the additional squeeze actually adds lift to the cam. So ultimately that extra half a turn allows more left at the valve to occur and thus will make more power over the curve.
@@davidcarson7542my dad never really explained the theory or reason. He did always say to put a 1/2 to 3/4 turn into them, for our mostly stock race car engines.
Really like these types of videos, swapping parts for testing and comparison. Super informative, love the content guys
L
I love the build videos for entertainment, but these videos are worth thousands of dollars for those of us chasing after torque and horsepower.
Should check out Richard holdener he has so many different videos of such nature.
@@stephenbianchi7141 you're Darn Tootin
@@trianifeA7xI love his videos and information.
Do a set of camshafts with the same lifts but different duration and different LSAs. We all know what they all do but to see a video of them all, that would be neat
Awesome idea
You need to watch Engine Masters.
David Vizard did that on a 350. With no other changes, closing LSA pumped up torque, widening LSA flattened the curve and improved idle. Duration moved torque up the rev range until heads couldn't flow past 6500rpm. 108 LSA, 252/254 duration high lift cam 1.6 rockers on exhaust side, ported 2.02/1.6 old 186 heads made a killer street engine.
@@marthamryglod291from my understanding David Vizard measures lsa from peak lift to peak lift of the cam lobes. Comp cams measures lsa center to center of the open and close events for each lobe. According to Vizard, displacement picks the lsa, overlap is what changes idle quality and rpm range in his video's that I've watched of his.
So in theory from my understanding you could have a something like a 270 duration cam (116 lsa how comp measures it) with asymmetrical lobes that would idle smooth like stock and still have the torque benefits of say a 108 lsa cam as long as the lobe peaks are still at 108. Duration would be determined by your static compression ratio and what you want your dynamic compression to be.
I'd love to see a test where someone took 2 cams say something like a 116 lsa cam with the same overlap at 0.050 lift. But one the peaks are at a true 116 lsa how comp measures it and the other with asymmetrical lobes that puts the lobe peaks closer to 108 lsa for a 350 or 106 for a 383. Ironically according to his formula a 110 lsa is the optimum lsa for a 305 so why is basically every comp cam in the catalog ground for a 305 😂😂
We don't all know exactly what it'll do, I'd also suggest same duration and LSA but different max lift
15:57 People who work with EFI will have a chuckle at how the crankcase vents in the exhaust stream directly ahead of the oxygen sensor that the Sniper unit is using to read and calculate fuel flows for the unit. Added air "fools" it into thinking the engine is lean and therefor enrichens the mixture.
Yep.. and, having the o2 sensor too close to the end of the exhaust can give you an erroneous reading
enrichen isn’t a word. It’s enriches.
@@coreymacqueen4802 Thanks for enrichening my vocabulary.
Thank you finally someone actually understands how to set lash on a hydraulic lifter whenever I explain this to people they look at me like I’m stupid
Yet in reality there is no need to do eo/ic on a stock/mild hft cam as you are far from the lash ramp. Up at 240@50+ on flat tappet or less on roller stuff then yes you need to be doing eo/ic. But there's no harm in educating people to do it this way as it takes the guess work out of it
These guys don't know that -0- lash isn't to make more HP, it's to prevent lifter pump up... they should have done 1/8th turn lash to limit pump up to a minimum...
Finally someone ? It's so basic makes me want to puke.
@@8power857 thats the only way to do it, one up one down. We used to do engine running , back off till they clatter, tighten till they quiet, + qtr. Turn. Just makes a hell of a mess on your fender wells.
@@ronniecox109 its not "the only way to do it" as you say then describe another way to do it 🤦♂️ , there are several ways to obtain correct adjustment. All work if done correctly.
One of the craziest things I've seen: My first car (bought in '76) was a '69 Torino GT, with a fairly worn-out stock 302 2-barrel and 3-speed manual. It would stop pulling at about 5200 rpm, which I attributed to valve float.
I was buying up parts to build a serious 289, and had a single four-barrel tunnel ram on hand. I also came across a Holley 465 cfm four-barrel (I think the smallest they made, w/vacuum secondaries, of course) that an acquaintance was selling. So I thought: "Why not?" I was running the 302 HARD, since I was planning on replacing it anyway.
So I popped the tunnel ram and Holley onto the otherwise-stock 302. Started EASILY pulling past 6000 rpm, and was otherwise a MAJOR improvement in power from launch on up. Only thing I can think is that it worked so well because the carb was SO SMALL! : )
The stock 302 2v even has push it valve spring studs. So if you want to run high rpm without destroying it, you need to install screw in studs and stronger valve springs.
@@charlesvan13 Need screw-in studs with higher lift cam & higher spring pressure, not just because you rev a stock cam high. You'll experience valve float from the weak stock springs before you pull a stud out
@@foxfordcatguy2283
The base engines are just made to run up to about 4400 RPM.
If you build a 302/289 for performance they wake up at over 5000.
Great video guy's. I have always turned 1/4 turn after zero lash with really good results. People kept telling me go 1/2 turn but understanding hydraulics and design of the lifter it only made sense to me to lightly preload since the lifter was designed to do it's job efficiently.
One of the best parts of these videos; is how genuinely happy Pat is , with the dyno results.
I love seeing what these parts do with a stock cam and compression to get a base line on small changes. Because sometimes people dont want or dont have the money to get to deep but want there car to be as efficient as it can be. Nice test!
Remember folks, it's not the engine they're comparing, it's the intakes and fuel deliveries. A worn out 305 is good, as long as it's the same worn out 305 with every test.
It was definitely worn out. it should have been pushing 250hp and 300lbft easy.
@@kskip4242 yo, what? Stock 305 aren't 250 hp and 300 tq
@@blakake the factory 150-170hp figures are with mild tuning and restrictions on everything. Get rid of all that and yes you can if the engine is still pushing good compression. Where people always go wrong with a 305 is they put way too big of camshafts in them. With the proper camshaft and some Vortec 305 heads you can easily get over 300 horsepower and 300 lb ft of torque. I have done all these things when I was younger so it's not like I'm just talking out of my ass I've been there and done it all. The 305 is not as big of a turd as people make it out to be.
@@blakake Stock log style 305 manifolds hold back close to 40hp alone.
@@blakake Ok I was off a little, just found my old dyno result from my G- body with my 305 and it was laying down 192hp and 244 lbft of torque at the rear wheels.This was with a reworked Q-jet off of a 327 small block, long tube headers, 32 degrees timing and other fuel tuning. The big killer on those factory set ups besides exhaust flow is those ancient computer modules that control the carb- timing ect.Oh I had an aftermarket vaccum advance HEI set up also.Keep in mind those numbers were after drivetrain loss.I was running 100 octane gasoline no ethanol also.
This video came just in time, I am working on a Chevy with a 305 and wasn't that sure about some timing things, so this saved me.
You guys are heroes!
Greets from Holland.
Just curious, is a chevy pretty common or uncommon over there in Holland? I'll admit to my ignorance being a US boy but just was an interesting thought
@@ryanroberts3742 as a old-timer yes, in the Netherlands Chevy's are very common. Well asking questions is always a good thing, how else will we learn things.
But as daily stuff we have a lot of 4 and even 3 cilinder cars (ford, Peugeot, Skoda, VW, etc) because of the high gas prise and emissions rules.
I wish we would have more V8 stuff here because we have to import everything we want to do on our V8 old-timer cars.
before you do a cam, i want to see a 1.6 ratio rocker arm swap on just the exhaust valves and then a full all round 1.6 swap. because no one ever tests the stock cams and changing the lift via the rocker. i want to know what everything else really adds compared to a cam swap, cause we all know that a cam ads power
Definitely some one needs to
You will flatten a stock 305 camshaft in short order doing that.
@@kskip4242 but will that actually happen, because if it would, wouldn’t it happen to any cam, sure the 305 has a cam heat treat problem but what about other engines
@@Andy47357 its not every single 305 ever made...... it was just a specific batch of bad cams
@@Andy47357 dude, my dad bought a 78 monte carlo with a 305 with a flattened lobe on #7, and it had 68 THOUSAND MILES.
I really want to see what throwing a fresh timing chain on it would do
And a cam
Didn't some GM engines have plastic coated gear on camshaft? Seems I saw one that the plastic gets crispy and starts coming off on high mileage motors.
Good job.
Everyone should own a Dyno!
I’d love to see a power run with just new valve springs
Can’t believe that old worn out 305 picked up power with a 950cfm carb. I figured that would of been to big for that old stock motor.
Yeah I'm sure it would make way more power with a 650 but the 950 probably has a higher profit margin and on a Dyno with unknown load why not run the biggest most money carb
on my '87 CRX after i rebuilt the engine, I'd put about 3/4 a bottle of seafoam into the gas tank, and the last 1/4 in the oil. ran that several times, doing a full bottle every 3rd gas tank and a 1/4 after every oil change.
took a while but it vastly cleaned up all the gunk that was left behind in the rockers and oil passages in the crank/rods and cleaned up the valves really good
Circle track guys may consider "zero lash" by taking out lash altogether and adding washers inside lifter to greatly reduce hydraulic space. Making it act more like a solid lifter. Alot of measuring is done inside lifter bore and the whole job is alot of time taking measurements.
It does increase power by a few.
220 hp is better than I thought it was going to pull. I figured 210@ best. Great job guys. Best of luck 🍀🍀
Good idea working on a base engine to show the increase with the dif. manifolds
One of your better episodes - love the comparisons.
I had a donkey; I called him Oatey. I liked my donkey Oatey.
I remember Pat teaching me at SAM in the late 90's. He was a cool cat. I'm glad to see he's doing well.
I've seen enough SBC dyno tests to know. For a street engine, get an Edelbrock RPM intake and call it a day.
Not even that just a base performer will do great numbers under 340-ish horsepower
@@theeoddments960 Torque baby
@@raylaux8295 all day every day
Or similar high rise dual plane...
yep,got a couple of them.one for regular sbc heads and one for the vortecs im now running
I had always set the lash preload at zero plus 1/4 turn. I always felt that 1/2 was a bit too much. You can hear the engine labor each time you go from 1/4 to 1/2 turn. But zero lash is not enough because you will lose a small amount of lift and duration. Anyway... that is my theory...
I see some videos with 3/4 turn
@@starfirerider if you are doing 3/4 turn on a GM motor..... you are an idiot LOL
.
GM valve train is DESIGNED to be zero lash - zero preload
that gives you the best lift, duration, wear, friction, and float protection
.
zero lash is NOT going to loose any lift....
its a hydraulic lifter!!!!!!!!!...... that 0.0001 lift you are "loosing" is simply taken up by the lifter pumping up
.
besides... hydraulic lifters will ALWAYS loose a bit of lift over a solid lifter.....
again, due to it being HYDRAULIC!
.
the oil WILL compress a bit.... or leak.... or back flow
reducing lift
.
.
.
but its SUCH a small amount
probably 10HP on a 500HP motor......
.
the difference between 500 and 510 (or 490) is NOT going to be felt..... nor will you be able to tell on your 1/4 mile times
.
.
you can easily make up for the ~10hp loss by setting up your car better.....
or not eating that large pizza before you put on your race suit
Both are good intakes. Really depends on your combo. My 496 big block makes 550 foot pound of torque at 3,000 rpms with a dart single plane. I could only imagine if I had a rpm air gap intake on it.😜
It would make less power at high rpm. Someone with a big block with over 500hp should know that. Stick with the single plane.
@@springwoodslasher79 Easy there turbo, he specifically mentioned torque and a low RPM. And it's youtube comment section bench racing speculation, I think it's alright to wonder about an AirGap.
@@Kstang09 IF YOU KNEW ANYTHING ABOUR CARS YOU WOULDN'T NEED TO WONDER ABOUT THE AIR GAP.
@@springwoodslasher79 you gotta remember though that any BBC is built for low end torque, ESPECIALLY the 496/8.1, most guys with em care about torque, not hp
@@lomfmur the guy im responding to has a 550hp big block v8 so your. 8:1 argument is beyond ignorant. Most guys care about torque not horsepower? Lol 😆 🤣 😂 😹 ... seriously GROW A BRAIN.
I’d love to see a cam kit, a thinner head gasket to bump up CR, and different types of headers next.
i can testify...a semi worn out 305 loves more cam(i used the l-82 vette cam) better heads (i used vortecs) a dual plane (edlebrock rpm ) and a 650 holley...makes for a fun mini mouse.....this engine has maybe 8-8.5 to 1 compression and lives on 87 octane
I'd like to see the test done at 1 full turn the way GM always recommended back in the day. Plus I never made an adjustment on new lifters without pre oiling the engine by using a adapter and a drill to pump up the oil pressure up.
It takes ages but you can actually turn the lifter almost to the bottom of travel. It requires a bit of planning during build up as the pushrods may have to be longer but there are some advantages and you guessed it, some disadvantages. There are some really excellent articles for racers that must run hydraulic OEM style.
The rest of us can run short travel lifters and they need to be set exactly as the manufacturer recommends.
1 Full turn can pump up the lifters until the valves hit the pistons at high RPMs with a performance cam... 1 full turn is to avoid ever needing a readjustment on stock cams...
@@BuzzLOLOL so you're an L1 certified Master Tech like me, who has been to GM School. I've done hundreds of engines setting up one full turn on a new set of lifters on a new camshaft. If you're afraid of lifters pumping up go solid lifters like a good old Duntov 30/30 camshaft.
@@marlobreding7402 - No, I'm a GM Engineer who went to GMI... Mary Barra also went there but 13 years after me...
Hydrolic lifters need to be soaked and void of air.
You can basically get any SBC engine to make 1 horsepower per cubic inch and run over 100,000 miles and that includes the 3 V6 variants. So how is the little 305 junk??? The challenge here are you smart enough to make a small engine put out good power and stay together. The money we spend on our junk does not play into it. If you want to talk horsepower per dollar you just go buy a complete engine ready to run, but what fun is in that???
@General Mayhem A good friend of mine put some type of camshaft in a 267 that was in his Chevy Monza and topped it with a Performer intake and a small Holley carb. Even as a teen I found that car was one scary ride. I told my buddy that all the work he was doing wouldn't help much, man was I ever wrong. It would peg the 85 mph speedometer in second gear.
Pat with his dad jokes, he should start his own youtube channel
i got a bone stock 305 c. i. worn out weezer with an edelbrock Super Victor II intake popping through the custom hood and 1000 cfm demon carb maxed velocity in a fat tire firebird, runs like hell through the turns dies at yield signs. i need to move up to a dual carb tunnel ram with velocity stacks.
That was a damn good video. Use this as a model please for future episodes. Dual plane for the win.
they should have stayed with a carburetor, especially using a dual plane.
I remember back in the 80's Eddie Bristol would adjust the rockers with the engine running and oil would be going everywhere and he told me and my brother that this is the proper way to do it. 😂
Take a old valve cover and cut it in half longways. Keeps oil from going everywhere
Score one for Frankie with the Dad Joke! He's learning how to beat Pat at his own game! (ROFL)
Hey guys my name is Cecil y'all are awesome and really enjoy what y'all do and teach👍
You had no valve spring pressure. Thats why it liked extra 1/2 turn. It kept more compression that way.
The extra half turn would work against the springs on base circle
Thanks for the timely humor, too ☺👍
305 love....im in they love a set of milled vortec heads, more cam and headers
Frankie developing his set of pens etc in his shirt pocket. Way to go
I think they skipped over some things. The sniper system requires a single plane intake or at the very least an open spacer or you will have problems. Also for accurate results you would need to let the system learn between part swaps. The first pull on the system will run well, but it will keep tuning itself. They also did not show any timing adjustments with each swap.
I want you guys to do a single plane va dual plane video like this, but test them on a bunch of different SBCs. I'd like to see how the two intakes affect a 175hp 305cid vs a 325hp 350cid vs a 500hp 383cid. That sounds interesting.
I know this is an old video, BUT it's so cool to see a usd 305 on the dyno!!! Who does that!! :) ... Nice to see stuff we are stuck with in our work trucks??? Up on the Dyno!!
I don’t care what anyone says about the 305, I like them. All the intake manifold test proved, is that the intake isn’t the restriction on the engine. The heads are the restriction. If you do a head shootout you’ll see bigger horsepower gains with the different manifolds
In 1978 I had a 77 Ltd II, 351W. Had cylinder heads, both crack water jackets. Never did dyno but with the Torquer 2, Holly 600, and 74 Torino long tube headers with 24" cherry bombs, a 30mph tromp would break the tires loose. A bonus was going from 15-16mpg at 55-60mph to 20 at 80. Never let a woman drive your car if you plan on keeping it
Very informative and fun, Thanks a lot for sharing.
I prefer a "hot" cam with a single plane intake and a "modest" carb to get a good,
high-revving small block. If running a big block, I would go with a dual-plane
intake, since they usually don't rev as high and you want that low rpm torque.
Pat just an fyi. Been spinning that pushrod to find zero lash for 40 yrs! Never had a single mishap with this method. Also , every professional engine builder i know does it this way as well. I'm not sure, but i think the way you showed, is how most "in their garage builders " do it.
SO much easier and faster to do this with the engine running. No messing around with base circle, which order to do it in, can get the whole engine done in 2-3 minutes.
I Love that Dyno VooDoo that you do.
Great work Pat, thank you for good information. You are the best...Keep it up. SGT DOUG
Love to see u guys do more mods on this 305 like heads & cam
Single , Single turbo , Inline V 6 , all wheel drive or I'm a supercharger guy myself ! But , all the philosophies I've ever heard throughout the world really has flew out the window Because of the power nation crew , and Mr . Pat all jokes aside My professor
Thank you guys!
Mayo “neighs” lol 😂. You got a pretty badass day job there bruh!
Basic rule of thumb if you want to produce a lot of torque low down before 1500 RPMs a dual plenum intake is nice if you're planning on racing street strip style and your motor makes more horsepower above 15,000 to 2,000 RPMs a single plane intake is perfect because the RPMs are already up there past 1500 1800 RPMs so you don't have to worry about the full RPM ranges
The zero pre-load for hydraulic lifters was part of the Royal Bobcat tune for 421 Pontiac engines in the GTO in early '60s. Interesting results from your dyno.
When did Pontiac ever put the 421 in a Goat?
Your video did get very close to a full explanation of the heater by pass port. But can you get more detailed like showing the hose connections and showing the exact flow of the heater hose outlet on the water pump to the manifold. Is that from the manifold flowing into the water pump? And the hose coming out of the manifold, can it go to the heater core and back to the radiator too right hole to allow bypass while engine is warming up?
Thank. You for your help on this?
Wait a sec.
Pat is in no position to determine if his young partner has good or bad jokes.
Has he ever heard his own corny jokes? Lol.
Throughout one of my tenures working at a dealership, I attended a GM Good wrench School,, and was always taught on GM V8 engines while the engine is running cold when you first start the engine is when you adjust your valves back it off until it clicks turn it quarter of a turn at a time until it stops and then a half a turn to finish.. and do to that other than the fact of putting an engine together and taking the lash out of the valves on a stand (spinning the pushrod) just to get to a starting point that's the way that I was taught to adjust valves from Mr Goodwrench himself..🤔
I noticed the earlier runs were with alternator and water pump installed for cooling. The current run is with an electric water pump. How much difference in parasitic drag did that make?
15-20 HP
Gotta do something to make the money spent = more HP !!!
20 - 30 h.p. when you combine the drag from both the water pump and alternator.
I recall another video where they tested alternator makes basically zero difference, it was 1-2hp which is within margin of error imo. There's just not enough resistance in a "reverse electric motor" to make a difference on big engines like these.
It's not a debate.. street engine needs a dual.. if the car has a camshaft that makes power up top and lives its life at 4k -7500 has deeper gears. A loose converter. Start lookin at a single...
I think you guys should add a few more commercials. Ive always tightened the rockers until the pushrod spin just starts to drag then let hydraulic pressure finish the lash. Ive never had a problem during start up, run or race.
Hi what header brand are those? I like them because u can get at the plugs easy..
bought a two year old 68 Camaro that had a 210 hp 327 two barrel. That thing ran like a beast beating many 350 lemans etc. loved that car. the wife could get mid 20;s gas mileage. Me? not so much. fun video thanks.
I picked up 500 rpm using a small economizer intake with a 302 stock ford engine with a600 holley carb on my airboat. Before 2500 rpm after 3000rpm . With secondary set to open quickly it gave snapper performance from 2000 to 3000 rpm but no more rpm.
On the run with the duel plane intake manifold, did they leave the Lash at 0 or back to 1/2 turn?
I want to see you guys do something over the top cool. Do the best dyno run you can with a flat tappet cam with an .842 lifter and then bush the block for a .904 lifter and see if its way better.
Good to see you test a stock motor . Setting the values at zero will let the eng rev higher without floating.
I have a somewhat stock 350 with a mild RV cam I am running a Edelbrock 1701 intake with a 1405 carb! I also have a open plane 1/4 spacer! The reason I ran the spacer is heat issue carb was getting too hot! My question is should I put a dual plane spacer or am I fine with open plane?
Love Pats look at 1:11, priceless.
I really appreciate how bare bones this 305 series is
Could you guys maybe do a super advance ignition timing study? My little brother made a setup to work off of a choke pull, that we hooked to a rotational plate on the distributor. (He was a machinist/mechanic. While you couldn't start a car at 37 Degrees before TDC, you could start it, and then rotate the distributor, after running. The torque and HP gain was phenomenol. Then again, a few times, I over did it. I was given a Geo Tracker that was painful to even drive. I bumped up the timing, and would squeal the tires both taking off and shifting. After 6 months of enjoyment, I broke the crankshaft between cylinder 2 & 3. OOPS! Please do a video on static timing on a SB Chevy. Thanks
Would have liked to see the differences between manifolds with the carb from the last video instead of the efi.
You two blokes are great to watch, loving the terrible dad jokes they are so bad they are awesome
Another comparison you could do is a Marine cam vs Truck Cam vs General Automotive cam.
The Horse joke made this video so much better!
They said they have never pulled the valve covers until after the ran the seafoam. How can they say how good it worked🤦♂️. WTF lol. I guess they will say anything if they are getting paid to.
Sludge that's built up in the oil passages that we can't see
It's all in the oil. They changes the oil like 5 times before using the seafoam and it came out black. Seafoam does work. Just a poor representation
Imagine if your job was just to throw mods at motors and test them on an engine dyno. Living the dream 😎
I like this dude I been watching him for years he's a really good mentor he's always teaching and sharing his knowledge
I've always wondered if runner length is more important than single plane vs duel
You guys should throw heads, cam, rockers and springs on it and see how much you can get out of it.
I would LOVE to see a video testing different styles of pistons. I'm building my 69 c20 and having the motor rebuilt but I've already put in a t56, disc conversion on the back, and a few other little things but I'm planning to build another engine for another build and seeing the pros and cons of different pistons would be helpful. The same about cams
God dam it it's not a motor.
@@raylaux8295 what the hell are you talking about?
Piston choice is determined by application. N/a boost or nitrous will determine material. Desired Compression and combustion chamber shape affect piston shape. Dome /dish valve relief. Cam choice can also affect piston to valve clearance. There's a bazillion old school chevy builds to use as a guide.
I would be interested to see a test on an old school factory or Offenhauser dual 4 barrel crossram.
This video gives you a great concept for how well engine components complement each other. The intake it came with and the ones that aren't really matched for it, all make roughly the same power. This tells you that you're essentially at the limit for the heads and cam. The cam just isn't going to open the valves enough or long enough to get any more air through and the heads probably won't flow much more anyway. You can see where the power drops off north of 4500, that she is basically breathing through a straw.
Just google and look at the differences in a factory 305 head and the DZ302 heads from the first Z/28. The port sizes, the combustion chamber. Compare the cam specs and look at the duration GM used with the old DZ.
Also interesting is that the TPI 305 that GM put in some F-bodies is more powerful from the factory than this Holley equipped van motor. Really shows what performance components can do.
Why would a 305 need a 950?
That 950 carb is actually probably hurting power on this motor. When a carb is too big the fuel doesn't get atomized as well and actually hurts power, that's even after the carb has been tuned correctly.
I've seen 430 horsepower small black chevys show no gain in power on the dyno once the carb got bigger than 750. Once a 950 was on it, power actually went down everywhere even when it was tuned correctly.
I can't believe there's not more comments about the 950. It's definitely to big for a 305. On a stock engine they should have ran a 500-600.
Exactly!
950cfm is out of this world crazy!
I built a 381 stroker Chevy with every sweet part I could throw on it (too a point lol).
It made 511hp and 492tq.
The carb is a 650cfm speed demon.
You want the absolute smallest carb on the engine you can get away with. Then jet it what it needs.
An engine is an air pump. It can only draw in so much air.
That little stock wore out engine needed a 450 or 500 cfm max. Then, jet it right.
The bigger the carb absolutely does not mean more fuel, more power. It's the opposite.
The smaller the carb, the better the throttle response. It draws a better signal to draw in the right amount of fuel (monitored with the jets).
Imagine putting on a 2000 cfm carb. More air and fuel? Nope. With a 2000 cfm carb, the same amount of air will be pumped into the engine, but the boosters and all the rest of the gizmos cannot sense the small amount of air running past the venturies. So if it cannot sense the air, it won't let fuel go into the engine. It'll be a dud, even if you put 1/4" jets in the sucker.
My 2 cents. I used to rebuild carbs.
@Common Sense Realist yeah. If I had to do it over again, I would build engine a bit differently now. I'd build a torq monster. I was basically a kid 16 years ago and I was probably going to race it at the strip plus I wanted higher hp numbers. I'd put a high lift cam, regular cam duration and a dual plane intake on it. I'd stick with a 600 or 650 carb tho. Instead, I put edelbrock Victor Jr heads and intake on it.
The cam I picked is good for a loppy idle tho 😉
Can u run a stock 460 engine 1985 with a carb spacer plates to see what top end horse power like the test run that Don with a 305
I've read that the tall center divider on some dual planes (like the one in the video) prevents the Sniper's MAP sensor from seeing both sides of the manifold which can lead to incorrect fuel ratios on some cylinders and erratic performance. It's recommended to notch the divider. Can we try that on this motor/manifold?
Where do I find information on auto-repair shops that can do this kind of detail testing in Georgia, for an AMC 258 4.2L in Jeep J10. Thanks for your video
When they switched to the Holly sniper Fuel injection replacing the 950 carb, they were pleased because the engine made a few more horsepower. The problem is that when the engine was running the Carb.it was also running a mechanical water pump and a alternator. When they switched the engines, the mechanical pump had been replaced by a electric water pump and the alternator was gone, that's where the extra horsepower came from not from the injection setup.
We're not supposed to notice that, or be mechanically knowledgeable enough to notice.
Good episode! Doesn’t it take the sniper a few runs to optimize the AFR? I’m also sure he misspoke on that first efi pull when he said 13:1 was rich.
14.7 is ideal. So 13:1 is rich but under load okay
Nah 14.7:1 is stoich so 14.7 parts air and 1 part fuel so 13:1 is 13 parts air and 1 part fuel so less air and same amount of fuel is rich
@@jasonhooey5677 in what world is 13.1 rich? Most power is being made for most engines at around 12.6-12.8 on my engine dyno. Pump gas has 10% Ethanol, which brings AFR down even more.
For fuel injection, which that motor is running, making 200hp, that's rich.
Big motors, big carbs and bigs cams totally different
@@jasonhooey5677 that is not HP related. I ran a stock 84 Vette TPI on the dyno the other day and it made peak HP at 12.8. When you have tons of overlap then yeah, some fuel flushes out the exhaust and you wanna make it richer. So I 13.1 at WOT is neither rich nor “super rich”, but rather lean. So the direction of that statement is wrong to being with.
I do love the 305 gm and this test made me very happy
Please do horse power increase or decrease with stock exhaust manifolds and headers, colder thermostats, higher ratio rocker arms, heavier valve springs, different spark plugs and wires, additives that promise horse power, lighter fly wheel and clutch assembly
At 04:55 the expensive EFI gained 4 HP but lost 6 lb.-ft. of torque!
@@crackjack8320 - More likely lost MPG since it lost torque... and the new EFI cars have to spin the engine over twice to start whereas carb. cars start the first time a piston comes up and you don't even hear the starter...
So a formative especially the valve lash segment. Proven by the dyno.
Mill heads .030" add cam hydraulic 230deg intake and exhaust at .030" lift .480" lift and 108deg lobe centers with hi rise dual plane.
Great video, wish you would have done the test with the 950 carb.
That’s what I was thinking! No longer apples to apples
The original intake installed looks like the old old torker sp intake. I would have thought that intake would have really killed bottom and mid range torque, but it didn't. Even with the itty bitty, worn factory cam, with a stretched timing chain.
I freaking love this show! I swear!, it is the only thing still cool in this world these days!
Also engine masters
Howdy P-N,
seafoam = "Petroleum Distillate" - why not just # 2 Fuel Oil or DIESEL ?
fuel-injection + a single-plane intake ...
Dual-Plane & a 600 cfm or 650 cfm Holley would have been more informative - IMHO
COOP
...
Can you do a single quad dual quad and six pack and see what is the best set up
I pulled the scorpion torquer of the SBC 385 (0.40 over) and put on an RPM air gap dual plane and the thing stomped off the bottom and screamed all the way to 7000 much harder than the old single plane.
I was going to go with an Air gap as well, but my Cam builder ( Mike Jones Camshafts) disagreed and said I would be leaving alot of HP. So a single, port matched, Vic JR has been in it and its an awesome street motor. Plenty of tire roasting TQ on tap, and a killer pull all the way to 6700 - 7000 rpms. Very happy. I do wonder how the airgap would perform though.
@@arodderz My cam is a Howards blower grind PN:110265-14 with Dart IK 200 Heads, Admittedly the old Scorpion single plane torquer is Edelbrock's oldest of that style of manifold, but the difference in bottom end and top end power is chalk and cheese, the power off the bottom is mostly noticed and is like a totally different motor coming out of a corner in second gear (Muncie 4 speed) with 3.36 rear gears just driving normally the tires start squealing just with minor input and it will just go up in smoke as you squeeze the throttle on, the torque delivery is like I bolted a 454 in it. My only complaint is I have to put a scoop on the hood of the Vette.
@@brianross4057 not sure how different the older type of single planes behave or work, but I know some may be to " large " for certain street applications, like the super victor. Glad your set up works for you. 👍. Maybe down the line, when $ become avail, I'll buy the dual and give it a go...i know it will do great
@@brianross4057 also, I'm on a 3000 stall, with 4:11s