That's good stuff , alotta folks don't realize there's some time to cut off the ol ET by learning a little about this subject. Redlining every gear isn't necessarily the fastest way down the track.
@Micheal Porter. I bought a kit from Summit racing for my 454 last year. The kit comes with the cam shaft plus Alum heads carb and intake and all the gaskets for $1,900 bucks. The heads even have ports for the fan and temp sensors and it bolted together amazing well. What I liked is the head bolts that came with the kit. The bolts themselves had locking feature when torqued in place. I don't know what grief that will cause in the future for removing those heads if need be but as far as power. I bolted on 75 extra horse power and then the headers and exhaust were another 15hp which was the perfect stew. All I did was bolt it together and my factory 5th wheel Silverado really hauls ass now. I was just impressed I had to do very little other work other than get the module for the trans and installing that new throttle cable and bracket can be a real pain in the ass like it was for me. The bracket Summit sells for the conversion is made for like a stock Q jet carb not the Holley aftermarket carb there is no hole in the bracket to hold the bottom in place so I cut the bullshit leg off their bracket and welded my own leg which goes farther back to the back map sensor bolt on the intake itself for some reasons the Holley intake has what appears to be bolt holes 4 a map sensor . Holley should make their own Bracket and cable kit as far as I am concerned but for my truck they don't make the stuff Edlebrock does. I am really pleased as far as value ease and performance the kit really wakes up a factory engine to tow a big camper. What does not come with the kit is an old school HEI distributor. That is sold separately and I ordered a factory performance Mallory set up off Summit and it also dropped right in no grief whatsoever. I you wanna take a 300hp and increase it just past 400hp that all in one kit Summit has is not bad for the cash because I have spent more in the past and got a hell of alot less for my money.
Just spent the last week healing from a wreck and decided to start building a stand alone harness for my 454 vortec that is being swapped into my k5 blazer(some day). I now have an accurate hp and torque number to tell to all the people who ask. Thanks for all the awesome info Richard! Love the videos keep them coming!
I tell guys like U and folks that come here a custom hand build from stray parts is not as cheap and easy as calling summit and getting cam and heads brand new bolts and gaskets for like $1,500 bucks to $2,00 grand instantly bolts on an extra 150hp. Headers and exhaust really make a diff too for the torque curves. Just of recent I noticed a real power increase on a build that I did last August. I didn't drive the damn truck but back and forth to the store a hand full of times because of working alot since then. I finally took it for a long drive down to my parents place a week ago and the thing really has a new set of balls to it. Some people are getting caught in the con jobs of those aftermarket LS style throttle bodies they sell. They were conning folks with those performance grade Air Idle units on em and all that other bullshit. I will say the best Air Idle to squeeze more horse power is a factory delco air idle does the trick. If use a new factory delco air idle and chip your truck from the get go that adds alot more power than those aftermarket air idles and throttle bodies ever will. There is not waiting in line for some lazy bastard at a machine shop to call ya your parts are ready when ya can call Summit and order the shit ya need brand spanking new and have the shit in 3-4 days all ready to go. I back Summit on alotta issues and the quality of stuff I get from em is usually decent stuff. Except for that fuel tank for a chevy blazer I built. When it came here it looked like Bongo the Guerilla worked it hour at his warehouse for a couple of days.
There is the 6.6l gen5 in new trucks. It has the same heads and camshaft as the lt1 in the corvette and makes 4xx hp. The intake is tuned for more torque and cuts 10-15hp off and the truck has a more restrictive exhaust.
@@timothybayliss6680 yes I know about that and its a neat idea, I haven't seen much done with it yet, ford has their new 7liter truck engine that looks like a big LS engine too
what's wrong with loving both of them.. just picking the right one for the specific application? For high torque application i'd use a larger displacement enginer. For higher rpms, my first choice would be a small block . I don't see any reason we can't have both. Ultimately you can make either do either role.. but there are easy ones.. and hard ones. that's just my logic.. yours may suit you better.
454 BBC vs 454 LS GM crate engines: 454HO 12568774 438HP @ 5300 500TQ @ 3500 Max RPM 5500 4.25 bore x 4.00 stroke 8.75:1 735LBS $6700 longblock with intake oil pan water pump vs. LSX454 19417357 or 19355573 627HP @ 6300 586TQ @ 5100 Max RPM 6500 4.185 bore x 4.125 stroke 11:01 536LBS $12,000 bare longblock only >Both may be 454's but completely different animals!
My 1999 Silverado 4.8 has 862 heads with cable throttle and my 2005 Silverado 4.8 has 706 heads with "drive by wire". Engine choice... I like both engines (4.8 vs 454). If I had to tow a lot I'd take the 454. Just for cruising around, 4.8 has all the power I need and probably gets better mileage than a 454 would. Thanks for all the great content. Best Regards.
Great Info and why I'm going with a Big Block in My 85 monte SS.. I'm just going mild GEN IV with 781 heads and low compress to get the 500 ft-lbs around 3500 rpm ( 224@.050 cam ) , use a 2400 stall in a 2004r and 3.73's to make it lots of fun on the street. No Racing..
idling at 65mph is hard on 1,2,3,4,5,6 cylinder engines. driving in the winter time, smooth traction is needed... so that huge torque curve will actually cause the truck/car to loose traction over ice.
Comparing driveable HP (3000RPM) instead of peak (racing) HP, the 454 is almost double. Under normal driving 2500-3500RPM, not counting passing, the 454 is so much better.
I want to see a test with a junkyard dirty old sbc 350 with an aluminum intake. 4 barrel. Headers. And mufflers. Like what everyone has. And then test it again with a fresh timing chain and basic cylinder head rebuild (minimal deck, clean, and valve lap)
I love the torque down low of big cubes. It extends down from this test as well. I had a VW with a turbocharged 4 that had about the same power to weight ratio of my LS3 powered SS. The small motor combo was on/off (spool it up to 4500 rpm to make it go, because anything below that was like walking). In my SS I can drive smooth but quick if I want, because it makes some power down low at part throttle.
@Keith Nevils. I have new body style extended cab SS concept truck made by Monroe Sport Trucks. That has a 4.8 in it. My son has my old body style black and red 99 SS with the 454. I dusted his ass twice now. That 454 is more suited for towing than it has speed to it. So this video gives a decent illustration about what I have been telling people for years now about the LS trucks. I prefer the 4.8 over the 5.3 because it does make more power than the 5.3's. I don't have a clue why that is but it is fact. I can't get a 5.3 much past making 400hp with basically the same parts I put on my 4.8's. Why is that??? Someone can tell me because in the last 10 years of building these things I do not have the answer why.
$$$$$$$$$$ I bought a mercruiser 8.1 engine for CHEAP and will be doing a HIGH HIGH horsepower build, heres some stuff I've researched. Decent engine, but stock heads are trash (thin castings, extreme weight and the exhaust port size is comparable to LS which is way too small) and piston to valve clearance really bites you in the ass BEFORE you can even get 230* duration camshaft in there. You have 3 options for cylinder heads in ALL OF THE AFTERMARKET, and you're FORCED to get a custom-grind camshaft for really good power (off-the-shelf cams are limited to 225* duration which is child's play). Theres also 1 carburetor intake manifold available in ALL THE AFTERMARKET (and its a dualplane, garbage) so you're limited to stock intake (trash, flows awfully) or Raylar intakes (which are $1200 and $3000) and EFI (same MPFI as LS). Toss a bottom end in there with a REAL compression ratio, REAL valve reliefs in the pistons, a REAL camshaft, some REAL CNC heads, a Raylar cool-gap intake, the sky is the limit for power. My build will be in the neighborhood of 850hp N/A, only after I spend the price of an arm and a dick for everything.
I did medium duty for years If you do anything to an 8.1 Toss the stock heads on the truck next scrap run Valve guides at 12 to 14k miles Cable truck PTO bucket trucks 3900hrs eguals 118k on high idle Plugs and plug wires were routine checks The plugs were caked w oil crust Then you have the dope spinning 8.1 oil filters on an md 6.6 Duramax Takes out the turbo I digress
Spec. Torque (454)0.980176211 (4.8)1.170648464 . Specific torque is higher on the 4.8... In a Drag race with identical gearsets my money is on the 4.8, due to the ability of the engine to maintain 300 ft lbs over such a long duration. Some interesting math ensued after I started looking into this, granted I had to make some graph guesses, but the 4.8 comes out way ahead in the (usable torque range*avg torque)/cubic inch. According to those numbers its almost twice as efficient at producing torque... Richard you are the man, keep the sweet thunder rollin'
I believe the only difference on the heads are where they are made and if it was a sand casting vs semi permanent mold casting. Technically the semi permanent molds can produce a slightly better finish but not in an appreciable way, especially once you open them up and go to bigger valves.
With different gearing, LESS WEIGHT and the mechanical advantage the LS will go faster in the same vehicle. I've installed quite a few 5.3's running a stock longblock and intake that took a big blocks lunch money. Your Gen 6 comparison is interesting because a 5.3 run in your test configuration also, more or less, equals the gross hp output of the Gen 6. I'm sure you've done that and should post the curve. Pick an engine, easy. A 5.3 LS punched out to use a 5.7 flat top piston and a healthy cam with LS6 or TBSS intake and your bouncing off 500hp for 1/3 of the cost of building a big block although your test of the peanut port 454 with the cam was VERY interesting.
If you compare rebuilding a 4.8L to any 5.3 rebuild using the same kits Summit sells. I have the 4.8's making 55 to 70hp more than a 5.3 and that is no bullshit. The first 2 times it happened to me I was thinking fluke or my imagination since the trucks were not my own. But after owning all 9 of my silverado's now all but one of em have the 4.8's and 5.'s. I have an odd ball 6.0 truck didn't even know that about it for the first 2 years I had it since it ran nearly the same as all the others that were in dire need of my attentions under their hoods. The 4.8 will make substantially more low end power and overall power when rebuilt. I can also get a much smoother idle curve out of the 4.8 motors.
@@thekingsilverado9004 Really, I thought there was no replacement for displacement and with the longer stroke the other LS's have a mechanical advantage but I never built a 4.8. The 9 engines I built were all 5.3's from mild to mildly wild, the latest is a 5.3 punched out to 5.7 using the stock flat top pistons, I'm hoping to crack the 500hp level with it for my '68 C10. I guess I'll have to look at the 4.8's for my next project, nobody wants 'em and I can have my pick for $200. I have a T5 and an S10 looking for 8 cylinders.
@@hardball107 Ken being honest as I can be most ppl do not have the science we have. As far as 5.3 to thee 4.8 the 4.8 is an enigma. It actually produces more bottom end honestly. I have only been working with these engines about 10 years but that is the truth. I have a 4.8 punched out 30 over and towing cam I got Thornesen that cam sold thru Summit line of stuff no one else. I shoved bored outa 5.3 engine off the grid put it up against my other 4.8 motors as far BOTTOM END the 4.8 won and the 5.3 actually gives a bit more hiway power or top end and peak speeds. The Hero 4.8 peaks out about the same so what I really mean is a built 5.3 built against a built 4.8 not much diff not at all. There is not much diff to be measured internally and I mean that not much at all about 1/4 inch of bore stroke and what is that total horse shit in reality. The 4.8 produces more low end power and torque and rightly so as to the way GM sold the shit in the early days. The 4.8 motors hold up much better too.
TBH the gen 6 barely beat the gen 5 ,especially considering the difference in the heads cam and all that good stuff ,i would have expected a bigger gap. Great vid as always.
If an ideal A/F ratio is present, it boils down to how much o2 you’ve got in the engine. So of course a bigger displacement is going to have more torque down low. Since HP is a function of torque and rpm, it makes sense that the big block runs out of rpm to make power, while the small block runs out of displacement. Putting the big block in a heavy car with a lot of traction is ideal, because it needs lots of torque to get moving and can put it to the pavement. If you put a torque monster motor in a lightweight/short wheelbase car, it could be extremely fast, but takes buckets of skill and maybe an under appreciated sense of well being to do it. Pushing those number further out in the rpm range makes it mor civil and streetable too. You don’t have to worry about spinning out every time you need to make a u turn... as much.
I know it is splitting hairs....but I am wondering about duty cycle between the two when making similar power. The little 4.8 has to spin to the moon while the 454 is loafing about to make the same number.....
They're kinda awesome. They have the same heads and even camshaft as the lt1 in the corvettes. The intake and exhaust is different. With an LT2 intake manifold off a c8 corvette and headers they would probably make 530hp like Richard tests them.
@@jbr496 Good question, I'd say run two tests - one with no weight handicapping to demonstrate power to weight ratio of a particular engine/transmission and one equalized to see if there's a real world difference racing side-by-side. In this case - an LS 4.8 vs. heavier Gen V 454- we'd see how identical power levels with different curves and different weights affect 60ft, 100ft, 1/8th mile and 1/4 mile times. To eliminate another set of variables, I'd say run the engines with stock heads, intake, and exhaust manifolds. I'm sure these tests have been run before, it'd been fun to watch Richard do it. Now he just needs sponsorship money...
What information would you be looking to gain from track testing? 10x more variables to account for and no tq and hp curves for side by side comparison.
The gen v came with a 197/202 @ .050 and .420 lift. I might be of by a couple numbers, but its close. Edit to say, it actually might have been a 193 duration on the intake. The vortec may have came with a 197.
The Gen V's aren't bad for starting grounds. Back around 92-93'ish a buddy of mine got one out of a wrecked truck and we put into his Monte Carlo SS. It smoked the original 305, but he wasn't happy with just that. He was able to find some oval port heads, a 4brl dual plane intake, and a bigger cam for dirt cheap. It was fun time in my life from late '80s to mid-'90s. I was a Mopar guy, my friend able was a GM guy, and our other friend was a Ford guy. We all helped out on each other cars, and helped each other pulling gear in the wrecking yards for each other.
Cool . Fast forward to 2020 , like this week lol. Ive got a GEN IV 454 going into my 85 Monte SS , 781 oval ports, 270 cam, stock compression. Keeping the modified 204r trans and going 12 bolt with 3.73's should be lots of fun. Oh and I'm 52 years old.. the car was bought new by my folks in July 85
I like the sound of big blocks. To take advantage of the 454 in a drag race. I would probably use a 2.56 rear gear and use something like a 3.73 for the ls. But what is the weight difference between the 454 and the 4.8 ?
I remember seeing somewhere that either the 862 or the 706 head was prone to cracking, so opting for the other was best if possible. Don't remember which one was problem prone though. It's probably info that someone has in their noggin.
That is bullshit. I have many sets of the 862 866 868heads someone said that to me at the Salvage Yard where I go get em from this one cracks and this one doesn't. There is not diff between that 703 or the 702 or 862 or 868 and 866. They are just diff casting numbers they take all the same parts to rebuild em and I never had an LS head crack yet. Infact I think in my own opinion these new style heads are one of the only things GM did right about the whole fuel injection set up. I get mildly oversized valves from a local company called Thornsen makes an HD valve and spring kit when that is added with any mild cam made for the fuel injection I instantly get another 100hp bolt on. I don't have to change the intake fuel injectors nothing. Add cam and valves and bolt it back together. Most of those 700 series heads are from SUV's and the 800 series heads are from the Silverado trucks is all is it is is diff casting numbers from diff GM engine facilities. Some of these yo yo's on here feed into too much drama bullshit. In fact those idiots that let a salvage handler charge em more for those heads should have their own fucking heads examined.
Got a nasty cam for my 5.3. duration 236/246, lift 612/612, LSA 110. Going in my 99 Silverado standard cab / long bed. Lots of other goodies for the engine to. Going to be a fun street/strip truck.
Video idea. A lot if us don't have access to an engine dyno, but comp cams has its canquest software. Can you show us a comparison of their software's hp and to estimates versus your actual measured numbers with the same parts? Anyone can find the head flow numbers and compression and select a cam, but you have actually done it. Just a suggestion. Keep up the good work!
@@johnnyboyssite I have desktop dyno 2000. Lol. I've had it for a looong time. It's very similar to comp's camquest6. I've always heard the calculators are a little optimistic but I'd like a little proof.
I would choose a big block every time for the low speed torque, but big blocks don’t exactly fit in every vehicle out there, and the additional weight on the front suspension isn’t good in certain vehicles. Obviously the lighter, more compact 4.8 or 5.3 is a better choice in said vehicles. Both engines are great and definitely have their place. 👍🏻
I've got the gen V TBI and it gets around 9MPG in mixed street highway. All freeway 12 if lucky. I began using no ethanol fuel and I find I get a much smoother idle and about another 0.5 MPG. This with all synthetic fluids, complete tune up, incl new distributor, complete new fuel system. It is an absolute pleasure to drive in fully tuned stock form. I made sure the exhaust is all 3" after the Y and have Magnaflow muffler and cat.
I think the 4.8 would b better the power band is larger so with the right gearing the 4.8 could make more average hp down track! Love the vids keep up the good work congrats on the 100k!!! I'm definitely excited about the giveaway!
The 706Vortec heads are even slightly superior to the commonly found 862 heads. The reason is that the 706 heads are SPM (semi-permanent mold) made, while the 862 heads are sand cast. The SPM method is considered to be a more consistent process, but once you port the 862 head, any difference to the 706 head goes away.
Higher RPM power means you can stay in a gear longer, and have more time with that mechanical advantage. They should be same track times if they have gearing that makes the same average horsepower through the run. That's the short version. And I chose the BBF or a Diesel... Were those choices?
In a way it's too bad the domestics don't have transmission ratio options like these here foreign job Volkswagens I been screwing around with for years. I can choose a 4 or 5 speed (nobody really uses the 4 speed) But the 5 speeds , wow, you want wide/narrow gear splits ? Tall or short diff? Theres like 20 of em for me to choose from. Pick your trans code and go hunting ! And if you really wanna get tricky, take a few apart and make your own ratio setup. The car I have is nice, but very slow as it's a non turbo diesel. I don't want to modify the engine ,but I can't have a Prius beat me I've only got 52hp. A close ratio short diff trans , and it rips a 10.5 0-60. I knocked off like 4-5 seconds from stock times that you see posted in old magazines. So yea, it's no rocket but I guess the point is there's so much more to be had in gears if it's not cost prohibitive.
Hard to choose an engine without having a project in mind. If I was building a fast road car, something for twisty roads, I would go with the 4.8 and add a turbo. If I was going for something on the strip only straight line speed I would go with the 454 and add a turbo. If I wanted something for hauling in a 2 ton truck I would go with a DT-466 and add a pair of turbos :) That's me and I have rationale for those choices but in the end pick what makes you happy and make it work. Way too many people say things can't be done and maybe they can't but outside of living in a Black hole most other things are possible.
I’m doing a 383 in my next tow rig for good low end torque but hopefully decent fuel economy. That’s the goal anyway. Everyone has their reasons, like you said
@@CraftsmanQuad19 That's a good choice. One of these days I would like to build a 1/2 ton 4x4 step side with something like that in it. You definitely don't need a monster engine for a big truck. My dad had a F-600, can't remember the exact year early 60's I think, that had a straight 6 in it. I think it was a 260 something. Dad would put six yards of sand or gravel in it and roll down the road at 55-60mph. I drove it around the farm when we were digging the basement for the house and other times. It wasn't a tire lighter but it worked just fine.
Parent of Twins in-line 6 wont win any races (not a stock one anyway), but they do hold up and work hard. I’ve got my LS race truck and this won’t be it lol. For a daily drivable 383, would you run stock iron heads, ported stock heads, or some aluminum heads? Smaller ports generally mean better throttle response, but I’m worried those swirl port heads will choke it even at low rpm. I’m keeping the tbi setup on it
@@CraftsmanQuad19 I'm not sure about the heads. I'm not going to pretend and steer you in the wrong direction. I have tried to get that question answered myself and have gotten mixed results. I guess it depends on how hard it is going to be to work on the engine once it is in the truck. If it's not a huge issue you could put on the swirl ports and see how they do and if it seems doggy change them out. If it is going to be a PITA to work on then I would ask in the comment section and hopefully someone with a similar setup or more knowledgeable than me can give you an answer. Sorry I couldn't help.
Parent of Twins hey man no worries. I appreciate your honesty. Id love to use vortec heads if I can find a tbi intake manifold that will fit...I’m not sure such a manifold exists
PLEASE do an iron headed LT1 test. My 96 Buick Roadmaster sedan needs more power but I have almost no budget. I can do most of the work myself. I just don't know what to do.
I'd say best bang for the buck would be tuning. over at gearhead-efi message board they have a way to flash the stock lt1 pcm diy without buying the expensive aftermarket software. there's a steep learning curve to tuning, but it's free to lean just lots of reading. which makes it the best thing for when you're tight on budget. as for what to hard parts to buy first, depends on how badly you wanna make your car worse to drive. big cars usually respond to big gears and loose converters in et at the drag strip. if you just want hp, the exhaust is a good place to start, like said above, rockers would help and can be found cheap used on the boards. but how much hp they would make if you'd even feel it. I don't know. gen 2 did seem to respond to a little bigger cam pretty well, but being such a big car, without the gear, converter and exhaust. it will just lose mid tq and make it less enjoyable to drive and maybe not any faster in the 1/4. nitrous?
Yes I think with the right gearing the 4.8 could feel like it made the same torque numbers as the 454. At the drag stripe with all being the same car set up, I think the 4.8 could pass the 454 at the top end. Great comparison video, always enjoy seeing the difference technology makes on these engines.
The big block is heavier and if it doesn't launch, because cars that are heavier and make torque are hard to launch, it's over. If the 454 ever falls behind it will never catch up. The LS with the same driver in the same car will be faster every time. It will always trap better. It would likely be quicker as well.
To answer the question the 4.8 would win a drag race with both optimally geared. The 4.8 makes the same power peak but over a useable rpm it's average is higher. And that's before we discuss the weight advantage
@Daver G Well dave when U have a transmission not much bigger than a school kids pencil sharpener the torque curve dives on the race track anyway. Actually less torque in a race engine is common otherwise you could find yourself in lunar orbit or a holding pattern over an airport till ya get clearance to land again. Too much torque on a race track will send ya off the track. I think the guy that could tell ya about that best would be the old man Dale. I worked a life time with race engines here and won 5 championships and what I can tell you is torque needs to kick in past 3rd gear not before.
Thanks for the informational video. It wouldbe cool if you can do a video on what make model vehicle you can find what engine in. In my local salvage yards i see many of the “LS” engines but i rarely find any 454 Engines or i just don’t know what i’m looking at.
Since HP = torque * RPM/5252.....With the proper gearing torque at the wheels will be the same just at a different engine rpm. The bigger engine will launch faster if the same engine rpm is used for both at launch. So it would be interesting to scale the 4.8 torque and power curves by 77% rpm and line it up with the 454 curve. The ratio of displacement of the two engines (4.8/7.4) is 65%. I'm not sure why the discrepancy between the peak power ratio and displacement ratio, but maybe it has to do with the cam profile, friction loss, compression ratio, and head design. Which one has the best BSFC????
Just a random rant, my 03 Silverado has a 4.8 and I’ve always noticed that these things make almost no torque, my 99 Sierra had an 06 LQ4 swapped in and I had torque and power for days in comparison to the little 4.8, they definitely leave a lot to be desired.
They make good torque. They just make it so high in the power band. They have no low end at all. My 4.8 sings from 4K to 5.5k. But the low end is none existent.
Chuck Nasty I have an lm7 out of an 01 Yukon, I’m gonna refresh the engine and use the flat top pistons from my 4.8 with a healthy cam, TBSS intake, and hopefully source some nice 243 heads. I’m not lookin for crazy power, I just want something that can accelerate moderately for a daily. I go over a couple large bridges and on the way up my truck hates life. Eventually I’d like to throw an lsa on top but not sure how likely that is, seems that swap has become more expensive now days.
I would guess that on a manual transmission all things equal the 454 would be faster than the 4.8l. On an automatic with a 4000rpm stall the 4.8L could match the big block. in acceleration.
Richard weird question but just say there was a planetary gear (%100 efficent or no power loss) to reduce the output rpm to about 75% of what the 4.8 runs to raise final drive torque as close to the 454s torque and test drove in same car same rearend gears and drivetrain the same.. what's your thoughts of the difference between the two motors in a drag race situation or just dyno numbers
Great videos sir! Been watching them for quite awhile. I sure would love to see you one day do some testing on the old BB 396. How would it compare to equal displacement LS? Would the BB heads help it perform compared to the LS? There still seems to be plenty of 396s out there that no one is interested in buying. For a street car, hot rod, rat rod whatever fun car, it seems like people should consider it an option. Or is it just not worth it? Sure would like to see you put your twist on that kind of comparison with all those tweaks and variables you always would into those tests. Keep the great content coming!
If both motors. We're in the same car with drivers weight reaction times ect the same. 454 gets the jump. 4.8 come around the back end. Be a tie at the finnish line. If the planets were aligned your at sea level at low tide. And your wearing your lucky boxers.
If you gear the 454 to work from 2500-4500 rpm and the 4.8l 3500-5500 rpm both have similar hp curves between those rpm and would be similar on the strip.
I want to see if you can find a combination of all stock gm ls parts to make power at the magic10k. I’ll bet you can with a large bore destroked combination.
Love them both, as you said, it would depend on the application. We all know it you add a turbo the curves just move up still making the BBC more powerful. Is you go mod for mod, the BBC is STILL gonna win! Displacement will always be king for torque and power. Aw hell just get them both and enjoy your playtime!
So much more aftermarket support of gen 6 and earlier big blocks that it shouldn't even be a question. Extra cubic inches is cool and all, but if you can't do anything to take advantage of em (you can't, its EXPENSIVE to make a good solid powerful 8.1), its trash. It costs an arm and a dick to make a 700hp 8.1
@@rustysausage69 That is true about the Gen V and Gen VI motors. I spent $1,900 on a kit from Summit last spring for my 93 factory 5th wheel truck. The kit was one thing and I spent another $1,000 on distributor headers & exhaust. You can get a cam heads new bolts gaskets and headers and stuff for an LS 4.8 5.3, 6.0 motors get all of that for $2,200 bucks. When rebuilding always replace the 0-2 sensors and the EGR stuff which does add about another $500 bucks but it also makes a diff when the build is done. I have a 99 New Body style extended cab SS really rare truck for one has 4.8 in her from the factory. I was pushing 300hp factory when I got her. Pulled the motor out cleaned the entire block added the Summit kit replaced the factory headers. I am push 470hp out of that 4.8 which is plenty. I can't hold it on the road past 135mph. At 135 the truck begins to like float on a cloud of air and I fear I would never be able to steer it down in an emergency so it's just for nice and sneaking up on the cholo's in their tuner cars. Just on a note on the factory Silverado those factory wheels none of em are speed rated period. Past 100mph you can get a nasty shake to the truck from the wheels. There are plenty of aftermarket wheels that also are not speed rated for going past 100mph. I found that out the hard way.
For whatever this is worth, I ran a 1 ton express van with 6.0 liter LS for 450+K miles, parted out the van (keeping the eng for future swap) then bought a 2017 express for my daily runs with a 4.8 and same "road gearing". The 4.8 is nothing in power compared to the 6.0, each of these were / are all O.E,M. in the same application and this is seat of the pants results.
I would like to see a comparison between the L86 and L8T engines. I don't really get why GM made two different truck engines that make nearly identical torque and hp numbers. What parts can be taken from one to make the other better? Are they really that close in power? Can you stroke th 6.2 with the L8T crankshaft? I've got lots of questions.
@@spareparts7630 With nothing but a factory cam swap and different tune, the stock 8.1 did OK. www.offshoreonly.com/forums/attachments/general-q/124495d1107971433-496-mag-h-o-torque-496ho.jpg
Richard, I think you are saying it backwards; horsepower is a calculated number based on torque and rpm. So the calculated horsepower curves for these engines are a result of the dyno measured torque values over the rpm range. HP is a result of torque generated at rpm.
@@richardholdener1727 Yes, the only measurable quantity that ic engines can generate is torque. Horsepower is a derived quantity that comes from the formula you mention. So the fundamental real world difference in your two tested engines is the difference in the area under the two torque curves between the normal operating rpm limits. I'd certainly rather have the 7.4L torque curve for everyday driving and especially towing my boat (but maybe not the added fuel expense!).
The 4.8 would need about 50% higher numerical gearing (say 5.29 with the 4.8 vs 3.50 with the 454) and a much looser converter than the 454, but both set up properly would ET and mph basically the same. LS is also probably 150 lbs lighter
I prefer making peak power between 2500-4500 rpms in my gas engines. My vehicle applications (work truck and station wagon) do not need to be revved out higher. At this tim I have a 366TD in my C60 that does phenomenal for what the truck is used for. Even though I've flirted with the idea of swapping it for the 427TD with a bit of performance modification. My 95 Caprice wagon came with a LT1 but a swapped it out for a Gen5 454. The wagon see's 28 mpg just on the stock engine. It has a 4L80 and 3.55 gearing and a 33 inch tire.
I don't think so. I have two Triton V-10's one in my F-350 and one in my E-350 van and they don't even come close chipped or not. Alot of it is the computers do not let them go past 4300rpm period and ya can't change the rev limiter on those computers. I don't get the throttle response like I do out of my LS trucks that just plain ole haul ass. I can't say that about some of the Ford Diesels running around here have some real nuts to em. Those Ferd coil packs they put on them Tritons and other engines suck from the get go. Also those R4L100 trans are not made for acceleration either. They hold up very well don't get me wrong but they are not built to throttle out like a chevy 4LE60's.
I know it's the bastard motor nobody wants to talk about, but have you ever done a test on a 366 big block? I've got one out of a 78 c50 I'm going to put in a 74 c30 for a while until I'm done building the original 454, I was curious to know what kind of power they make. I really can't find any information on them at all. Just curious to see what kind of power they could make stock as well as modified
does weight matching pistons and conrods add hp to either a stock engine or one with all the trimmings :) p.s u need lots of torque for pulling ? how about a diesel engine ;)
@@1worldgaming18 you should see how much of a difference going to a 030 over piston can do for the weight. I know they all weigh the same but it's more than youd think.
Hey Richard I was thinking about that destroke video will it work the same with a 289 crank on a 302 block? Or will the motor have no compression or will it just become a 289
You need 289, boss 302 or, and I don't know if it's true, turbo 2.3 rods, to use stock 289 pistons. Apparently the turbo 2.3l uses the C3 hi po 289 forging.
I have a combo for you that a lot of guys are drag racing and winning big. Rods and pistons 6.0/5.3 big turbo and big nitrous on E85 and 799 or 317 heads and meth injection and a self cam stage 2,3 or 4. And making well over 1000 hp. Is reliable and if done properly can easily be steerable if you know it's a drag car you're driving on the street. Just saying. That would be one hell of a test. How much can a good rod and pistons combo in junkyard motor handle. I think you will run out of map sensor again like on the big bang gen 4 6.0 you did. I'm sure you have the stuff laying around. Lol. Love the channel and what you do with motor trend. You need your own show on motor trend.
“Turbo everything” would make a nice sweater for the track on colder days
Yup...
I just want a 500 Cadilac with 500hp and 600 ft-lbs of grunt, y'all can have everything else. Yes the Caddy videos have ruined me for a while!!!
🤣
i like the 500ci in a 70s Coupe DeVille.. ;)
Had a 70 El Dorado. 502 cu in is nice. I outran motorcycle's in that car.
Watch my most recent videos then I have 2 trucks with them
I have one dyno'd at 500/600. Its for sale if you want a good deal on it.
Hp academy has a webinar on torque curves and shift points out this week
That's good stuff , alotta folks don't realize there's some time to cut off the ol ET by learning a little about this subject.
Redlining every gear isn't necessarily the fastest way down the track.
Show us how you would build the 454, to put in a tow rig, to take the rest of these engines to the track.
That has been done already on the channel
@@pr0n5tar I'll have to find it.
@Micheal Porter. I bought a kit from Summit racing for my 454 last year. The kit comes with the cam shaft plus Alum heads carb and intake and all the gaskets for $1,900 bucks. The heads even have ports for the fan and temp sensors and it bolted together amazing well. What I liked is the head bolts that came with the kit. The bolts themselves had locking feature when torqued in place. I don't know what grief that will cause in the future for removing those heads if need be but as far as power. I bolted on 75 extra horse power and then the headers and exhaust were another 15hp which was the perfect stew. All I did was bolt it together and my factory 5th wheel Silverado really hauls ass now. I was just impressed I had to do very little other work other than get the module for the trans and installing that new throttle cable and bracket can be a real pain in the ass like it was for me. The bracket Summit sells for the conversion is made for like a stock Q jet carb not the Holley aftermarket carb there is no hole in the bracket to hold the bottom in place so I cut the bullshit leg off their bracket and welded my own leg which goes farther back to the back map sensor bolt on the intake itself for some reasons the Holley intake has what appears to be bolt holes 4 a map sensor . Holley should make their own Bracket and cable kit as far as I am concerned but for my truck they don't make the stuff Edlebrock does. I am really pleased as far as value ease and performance the kit really wakes up a factory engine to tow a big camper. What does not come with the kit is an old school HEI distributor. That is sold separately and I ordered a factory performance Mallory set up off Summit and it also dropped right in no grief whatsoever. I you wanna take a 300hp and increase it just past 400hp that all in one kit Summit has is not bad for the cash because I have spent more in the past and got a hell of alot less for my money.
Just spent the last week healing from a wreck and decided to start building a stand alone harness for my 454 vortec that is being swapped into my k5 blazer(some day). I now have an accurate hp and torque number to tell to all the people who ask. Thanks for all the awesome info Richard! Love the videos keep them coming!
id love to see you do a build on the 8.1L 496ci vortec....like cam head work etc!
I tell guys like U and folks that come here a custom hand build from stray parts is not as cheap and easy as calling summit and getting cam and heads brand new bolts and gaskets for like $1,500 bucks to $2,00 grand instantly bolts on an extra 150hp. Headers and exhaust really make a diff too for the torque curves. Just of recent I noticed a real power increase on a build that I did last August. I didn't drive the damn truck but back and forth to the store a hand full of times because of working alot since then. I finally took it for a long drive down to my parents place a week ago and the thing really has a new set of balls to it. Some people are getting caught in the con jobs of those aftermarket LS style throttle bodies they sell. They were conning folks with those performance grade Air Idle units on em and all that other bullshit. I will say the best Air Idle to squeeze more horse power is a factory delco air idle does the trick. If use a new factory delco air idle and chip your truck from the get go that adds alot more power than those aftermarket air idles and throttle bodies ever will. There is not waiting in line for some lazy bastard at a machine shop to call ya your parts are ready when ya can call Summit and order the shit ya need brand spanking new and have the shit in 3-4 days all ready to go. I back Summit on alotta issues and the quality of stuff I get from em is usually decent stuff. Except for that fuel tank for a chevy blazer I built. When it came here it looked like Bongo the Guerilla worked it hour at his warehouse for a couple of days.
I been say that for ever!!!!!!
I wish gm would have made a 454 LS big block, based on LS architecture but everything bigger, that would have been an absolute beast!
There is the 6.6l gen5 in new trucks. It has the same heads and camshaft as the lt1 in the corvette and makes 4xx hp. The intake is tuned for more torque and cuts 10-15hp off and the truck has a more restrictive exhaust.
@@timothybayliss6680 yes I know about that and its a neat idea, I haven't seen much done with it yet, ford has their new 7liter truck engine that looks like a big LS engine too
THEIR IS A gm LS crate version of the 454. It's in the chevy performance catalog.
what's wrong with loving both of them.. just picking the right one for the specific application?
For high torque application i'd use a larger displacement enginer. For higher rpms, my first choice would be a small block . I don't see any reason we can't have both. Ultimately you can make either do either role.. but there are easy ones.. and hard ones. that's just my logic.. yours may suit you better.
Blagg Ironheart well Not sure about you but my truck only holds one motor That’s why .....🥱
454 BBC vs 454 LS GM crate engines:
454HO 12568774
438HP @ 5300
500TQ @ 3500
Max RPM 5500
4.25 bore x 4.00 stroke
8.75:1
735LBS
$6700 longblock with intake oil pan water pump
vs.
LSX454 19417357 or 19355573
627HP @ 6300
586TQ @ 5100
Max RPM 6500
4.185 bore x 4.125 stroke
11:01
536LBS
$12,000 bare longblock only
>Both may be 454's but completely different animals!
To add cam specs:
454 HO
Duration @ .050" 211/230
Lift with 1.7:1 rocker 510/540
Lobe centerline: 112
LSX454
Duration @ .050" 236/246
Maximum Lift (in) W/ 1.7 Rocker 612/612
Maximum Lift (in) W/ 1.8 Rocker 648/648 (LSX454 crate engine comes with 1.8)
Lobe Centerline: 110
Watching your videos has showed what an impressive motor 4.8 really is
easy fix on the 454 for relative torque... put a fairly stock grind cam in it that revs out as far as the 4.8 then see where power falls
My 1999 Silverado 4.8 has 862 heads with cable throttle and my 2005 Silverado 4.8 has 706 heads with "drive by wire". Engine choice... I like both engines (4.8 vs 454). If I had to tow a lot I'd take the 454. Just for cruising around, 4.8 has all the power I need and probably gets better mileage than a 454 would. Thanks for all the great content. Best Regards.
Probably? You mean it does? I've never heard of a 454 getting more than 8 miles per gallon 🤣 a healthy running 4.8 can get 20mpgs all day
Great Info and why I'm going with a Big Block in My 85 monte SS.. I'm just going mild GEN IV with 781 heads and low compress to get the 500 ft-lbs around 3500 rpm ( 224@.050 cam ) , use a 2400 stall in a 2004r and 3.73's to make it lots of fun on the street. No Racing..
Absolutely, Richard! Gears cure ALL torque deficiencies, but CANNOT patch in more power (actual work capability).
I’ve had turbo 8.1l and now turbo 6.2l. Both in 2500hd. Love ls and bb both.
idling at 65mph is hard on 1,2,3,4,5,6 cylinder engines. driving in the winter time, smooth traction is needed... so that huge torque curve will actually cause the truck/car to loose traction over ice.
Comparing driveable HP (3000RPM) instead of peak (racing) HP, the 454 is almost double. Under normal driving 2500-3500RPM, not counting passing, the 454 is so much better.
I want to see a test with a junkyard dirty old sbc 350 with an aluminum intake. 4 barrel. Headers. And mufflers. Like what everyone has. And then test it again with a fresh timing chain and basic cylinder head rebuild (minimal deck, clean, and valve lap)
YES
That would make a great video.
Would love to see that!
valve job and timing chain?
@@richardholdener1727 that would make an interesting conversation after the video aired
I love the torque down low of big cubes. It extends down from this test as well. I had a VW with a turbocharged 4 that had about the same power to weight ratio of my LS3 powered SS. The small motor combo was on/off (spool it up to 4500 rpm to make it go, because anything below that was like walking). In my SS I can drive smooth but quick if I want, because it makes some power down low at part throttle.
@Keith Nevils. I have new body style extended cab SS concept truck made by Monroe Sport Trucks. That has a 4.8 in it. My son has my old body style black and red 99 SS with the 454. I dusted his ass twice now. That 454 is more suited for towing than it has speed to it. So this video gives a decent illustration about what I have been telling people for years now about the LS trucks. I prefer the 4.8 over the 5.3 because it does make more power than the 5.3's. I don't have a clue why that is but it is fact. I can't get a 5.3 much past making 400hp with basically the same parts I put on my 4.8's. Why is that??? Someone can tell me because in the last 10 years of building these things I do not have the answer why.
Rich
What about the 8.1
Big Block
I have a bunch of ls engines
But no big blocks
With turbos
$$$$$$$$$$ I bought a mercruiser 8.1 engine for CHEAP and will be doing a HIGH HIGH horsepower build, heres some stuff I've researched.
Decent engine, but stock heads are trash (thin castings, extreme weight and the exhaust port size is comparable to LS which is way too small) and piston to valve clearance really bites you in the ass BEFORE you can even get 230* duration camshaft in there.
You have 3 options for cylinder heads in ALL OF THE AFTERMARKET, and you're FORCED to get a custom-grind camshaft for really good power (off-the-shelf cams are limited to 225* duration which is child's play). Theres also 1 carburetor intake manifold available in ALL THE AFTERMARKET (and its a dualplane, garbage) so you're limited to stock intake (trash, flows awfully) or Raylar intakes (which are $1200 and $3000) and EFI (same MPFI as LS).
Toss a bottom end in there with a REAL compression ratio, REAL valve reliefs in the pistons, a REAL camshaft, some REAL CNC heads, a Raylar cool-gap intake, the sky is the limit for power. My build will be in the neighborhood of 850hp N/A, only after I spend the price of an arm and a dick for everything.
I did medium duty for years
If you do anything to an 8.1
Toss the stock heads on the truck next scrap run
Valve guides at 12 to 14k miles
Cable truck PTO bucket trucks
3900hrs eguals 118k on high idle
Plugs and plug wires were routine checks
The plugs were caked w oil crust
Then you have the dope spinning 8.1 oil filters on an md 6.6 Duramax
Takes out the turbo
I digress
I wanna build an 8.1 with a hair dryer as a daily/tow rig ....thoughts?
That's what in putting in my 69 Chevelle
I always find your videos rich in useful information.
Spec. Torque (454)0.980176211 (4.8)1.170648464
. Specific torque is higher on the 4.8... In a Drag race with identical gearsets my money is on the 4.8, due to the ability of the engine to maintain 300 ft lbs over such a long duration. Some interesting math ensued after I started looking into this, granted I had to make some graph guesses, but the 4.8 comes out way ahead in the (usable torque range*avg torque)/cubic inch. According to those numbers its almost twice as efficient at producing torque... Richard you are the man, keep the sweet thunder rollin'
Im just finishing a 454 supercharged 70 Chevy c20 and i love torque but my next project will be a big ls because i also love efficiency.
I believe the only difference on the heads are where they are made and if it was a sand casting vs semi permanent mold casting. Technically the semi permanent molds can produce a slightly better finish but not in an appreciable way, especially once you open them up and go to bigger valves.
With different gearing, LESS WEIGHT and the mechanical advantage the LS will go faster in the same vehicle. I've installed quite a few 5.3's running a stock longblock and intake that took a big blocks lunch money. Your Gen 6 comparison is interesting because a 5.3 run in your test configuration also, more or less, equals the gross hp output of the Gen 6. I'm sure you've done that and should post the curve. Pick an engine, easy. A 5.3 LS punched out to use a 5.7 flat top piston and a healthy cam with LS6 or TBSS intake and your bouncing off 500hp for 1/3 of the cost of building a big block although your test of the peanut port 454 with the cam was VERY interesting.
If you compare rebuilding a 4.8L to any 5.3 rebuild using the same kits Summit sells. I have the 4.8's making 55 to 70hp more than a 5.3 and that is no bullshit. The first 2 times it happened to me I was thinking fluke or my imagination since the trucks were not my own. But after owning all 9 of my silverado's now all but one of em have the 4.8's and 5.'s. I have an odd ball 6.0 truck didn't even know that about it for the first 2 years I had it since it ran nearly the same as all the others that were in dire need of my attentions under their hoods. The 4.8 will make substantially more low end power and overall power when rebuilt. I can also get a much smoother idle curve out of the 4.8 motors.
@@thekingsilverado9004 Really, I thought there was no replacement for displacement and with the longer stroke the other LS's have a mechanical advantage but I never built a 4.8. The 9 engines I built were all 5.3's from mild to mildly wild, the latest is a 5.3 punched out to 5.7 using the stock flat top pistons, I'm hoping to crack the 500hp level with it for my '68 C10. I guess I'll have to look at the 4.8's for my next project, nobody wants 'em and I can have my pick for $200. I have a T5 and an S10 looking for 8 cylinders.
@@hardball107 Ken being honest as I can be most ppl do not have the science we have. As far as 5.3 to thee 4.8 the 4.8 is an enigma. It actually produces more bottom end honestly. I have only been working with these engines about 10 years but that is the truth. I have a 4.8 punched out 30 over and towing cam I got Thornesen that cam sold thru Summit line of stuff no one else. I shoved bored outa 5.3 engine off the grid put it up against my other 4.8 motors as far BOTTOM END the 4.8 won and the 5.3 actually gives a bit more hiway power or top end and peak speeds. The Hero 4.8 peaks out about the same so what I really mean is a built 5.3 built against a built 4.8 not much diff not at all. There is not much diff to be measured internally and I mean that not much at all about 1/4 inch of bore stroke and what is that total horse shit in reality. The 4.8 produces more low end power and torque and rightly so as to the way GM sold the shit in the early days. The 4.8 motors hold up much better too.
I wonder what they would both do with proper camshafts and then maybe a mild ported head? Top it off with some aftermarket heads. I’d watch it.
Look thru Richard's vids, he's done that to both.
What would be a really nice test is to use the same heads, cam and intake on all those different displacements.
My 4.8L is at 96000miles running great. Zero problems
TBH the gen 6 barely beat the gen 5 ,especially considering the difference in the heads cam and all that good stuff ,i would have expected a bigger gap. Great vid as always.
If an ideal A/F ratio is present, it boils down to how much o2 you’ve got in the engine. So of course a bigger displacement is going to have more torque down low. Since HP is a function of torque and rpm, it makes sense that the big block runs out of rpm to make power, while the small block runs out of displacement.
Putting the big block in a heavy car with a lot of traction is ideal, because it needs lots of torque to get moving and can put it to the pavement. If you put a torque monster motor in a lightweight/short wheelbase car, it could be extremely fast, but takes buckets of skill and maybe an under appreciated sense of well being to do it. Pushing those number further out in the rpm range makes it mor civil and streetable too. You don’t have to worry about spinning out every time you need to make a u turn... as much.
Great test. Also, the BBC will be much less stressed towing a heavy load. All other things equal, engine life is inversely proportional to BMEP.
I know it is splitting hairs....but I am wondering about duty cycle between the two when making similar power. The little 4.8 has to spin to the moon while the 454 is loafing about to make the same number.....
Your not wrong but The big block has alot of slinging weight so that into consideration the little 4.8 might have less wear over time
454 for the win!
“Displacement FTW”.
Im curious m. Say drop these both in 70 chevelles both with 4l80E. Im curious what et side by side would be
4,8 rpm would be screaming just to stay up with 7.4
Don't forget about the new 6.6 liter direct injection Chevy truck motor, I would like to see you tinker with that one.
They're kinda awesome. They have the same heads and even camshaft as the lt1 in the corvettes. The intake and exhaust is different. With an LT2 intake manifold off a c8 corvette and headers they would probably make 530hp like Richard tests them.
I’d suggest building two identical Comp Eliminator dragsters with a variety of engine and transmission mounts and do actual side-by-side races.
I'd like to see that too. What would you do about the weight difference? Add ballast to the LS combo to equalize the weight?
@@jbr496 Good question, I'd say run two tests - one with no weight handicapping to demonstrate power to weight ratio of a particular engine/transmission and one equalized to see if there's a real world difference racing side-by-side.
In this case - an LS 4.8 vs. heavier Gen V 454- we'd see how identical power levels with different curves and different weights affect 60ft, 100ft, 1/8th mile and 1/4 mile times.
To eliminate another set of variables, I'd say run the engines with stock heads, intake, and exhaust manifolds.
I'm sure these tests have been run before, it'd been fun to watch Richard do it.
Now he just needs sponsorship money...
What information would you be looking to gain from track testing? 10x more variables to account for and no tq and hp curves for side by side comparison.
My father had a Chevelle with a carbbed GenVI and a cam. It was a scary torque monster.
The gen v came with a 197/202 @ .050 and .420 lift. I might be of by a couple numbers, but its close.
Edit to say, it actually might have been a 193 duration on the intake. The vortec may have came with a 197.
Depends on the application I would think
I wonder what's the weight differences?
Big block is about 670 to 750lbs full dressed with fluids.
LS iron blocks normally weight about 420 to 500 lbs with fluid and accessories.
Was going to ask the same thing
Almost 345 pounds.
The Gen V's aren't bad for starting grounds. Back around 92-93'ish a buddy of mine got one out of a wrecked truck and we put into his Monte Carlo SS. It smoked the original 305, but he wasn't happy with just that. He was able to find some oval port heads, a 4brl dual plane intake, and a bigger cam for dirt cheap.
It was fun time in my life from late '80s to mid-'90s. I was a Mopar guy, my friend able was a GM guy, and our other friend was a Ford guy. We all helped out on each other cars, and helped each other pulling gear in the wrecking yards for each other.
Cool . Fast forward to 2020 , like this week lol. Ive got a GEN IV 454 going into my 85 Monte SS , 781 oval ports, 270 cam, stock compression. Keeping the modified 204r trans and going 12 bolt with 3.73's should be lots of fun. Oh and I'm 52 years old.. the car was bought new by my folks in July 85
I wish I had half your knowledge you do. love the the ls videos🤯
I only have 1/2 myself
For my 96 Buick Roadmaster sedan I'd pick the 454. For my 80 Monte Carlo I'd pick the 4.8
I would take the LS with a couple of Hong Kong hairdryers strapped to it.
Taiwan Typhoons....
I like the sound of big blocks.
To take advantage of the 454 in a drag race. I would probably use a 2.56 rear gear and use something like a 3.73 for the ls.
But what is the weight difference between the 454 and the 4.8 ?
You should do a video of the 8.1 if you haven’t already. See if they are worth the extra hassle since parts aren’t exchangeable with the older BB
I remember seeing somewhere that either the 862 or the 706 head was prone to cracking, so opting for the other was best if possible. Don't remember which one was problem prone though. It's probably info that someone has in their noggin.
That is bullshit. I have many sets of the 862 866 868heads someone said that to me at the Salvage Yard where I go get em from this one cracks and this one doesn't. There is not diff between that 703 or the 702 or 862 or 868 and 866. They are just diff casting numbers they take all the same parts to rebuild em and I never had an LS head crack yet. Infact I think in my own opinion these new style heads are one of the only things GM did right about the whole fuel injection set up. I get mildly oversized valves from a local company called Thornsen makes an HD valve and spring kit when that is added with any mild cam made for the fuel injection I instantly get another 100hp bolt on. I don't have to change the intake fuel injectors nothing. Add cam and valves and bolt it back together. Most of those 700 series heads are from SUV's and the 800 series heads are from the Silverado trucks is all is it is is diff casting numbers from diff GM engine facilities. Some of these yo yo's on here feed into too much drama bullshit. In fact those idiots that let a salvage handler charge em more for those heads should have their own fucking heads examined.
Got a nasty cam for my 5.3. duration 236/246, lift 612/612, LSA 110. Going in my 99 Silverado standard cab / long bed. Lots of other goodies for the engine to. Going to be a fun street/strip truck.
hope you have valve reliefs
Do you have a high torque starter? For initial startup?
@@richardholdener1727 Good point.
So did I do well getting a gen 4 4 bolt 454 then?
Video idea. A lot if us don't have access to an engine dyno, but comp cams has its canquest software. Can you show us a comparison of their software's hp and to estimates versus your actual measured numbers with the same parts? Anyone can find the head flow numbers and compression and select a cam, but you have actually done it.
Just a suggestion. Keep up the good work!
I've got the DeskTopDyno5 software and it is excellent.
@@johnnyboyssite I have desktop dyno 2000. Lol. I've had it for a looong time. It's very similar to comp's camquest6. I've always heard the calculators are a little optimistic but I'd like a little proof.
I would choose a big block every time for the low speed torque, but big blocks don’t exactly fit in every vehicle out there, and the additional weight on the front suspension isn’t good in certain vehicles. Obviously the lighter, more compact 4.8 or 5.3 is a better choice in said vehicles. Both engines are great and definitely have their place. 👍🏻
I still think studded gen vi bbc’s with sefi can dominate all. Except for fuel mileage. That is all.
I've got the gen V TBI and it gets around 9MPG in mixed street highway. All freeway 12 if lucky.
I began using no ethanol fuel and I find I get a much smoother idle and about another 0.5 MPG.
This with all synthetic fluids, complete tune up, incl new distributor, complete new fuel system.
It is an absolute pleasure to drive in fully tuned stock form. I made sure the exhaust is all
3" after the Y and have Magnaflow muffler and cat.
@@latrogeniwile58 .5 is a bunch better when 9 is your starting point.
@@latrogeniwile58 I implemented the highway lean cruise on my TBI 305 and I get 20mpg highway. Bet you could get 15
I think the 4.8 would b better the power band is larger so with the right gearing the 4.8 could make more average hp down track! Love the vids keep up the good work congrats on the 100k!!! I'm definitely excited about the giveaway!
The 706Vortec heads are even slightly superior to the commonly found 862 heads. The reason is that the 706 heads are SPM (semi-permanent mold) made, while the 862 heads are sand cast. The SPM method is considered to be a more consistent process, but once you port the 862 head, any difference to the 706 head goes away.
Higher RPM power means you can stay in a gear longer, and have more time with that mechanical advantage. They should be same track times if they have gearing that makes the same average horsepower through the run. That's the short version.
And I chose the BBF or a Diesel... Were those choices?
In a way it's too bad the domestics don't have transmission ratio options like these here foreign job Volkswagens I been screwing around with for years.
I can choose a 4 or 5 speed (nobody really uses the 4 speed)
But the 5 speeds , wow, you want wide/narrow gear splits ?
Tall or short diff?
Theres like 20 of em for me to choose from.
Pick your trans code and go hunting !
And if you really wanna get tricky, take a few apart and make your own ratio setup.
The car I have is nice, but very slow as it's a non turbo diesel.
I don't want to modify the engine ,but I can't have a Prius beat me I've only got 52hp.
A close ratio short diff trans , and it rips a 10.5 0-60.
I knocked off like 4-5 seconds from stock times that you see posted in old magazines.
So yea, it's no rocket but I guess the point is there's so much more to be had in gears if it's not cost prohibitive.
Hard to choose an engine without having a project in mind. If I was building a fast road car, something for twisty roads, I would go with the 4.8 and add a turbo. If I was going for something on the strip only straight line speed I would go with the 454 and add a turbo. If I wanted something for hauling in a 2 ton truck I would go with a DT-466 and add a pair of turbos :) That's me and I have rationale for those choices but in the end pick what makes you happy and make it work. Way too many people say things can't be done and maybe they can't but outside of living in a Black hole most other things are possible.
I’m doing a 383 in my next tow rig for good low end torque but hopefully decent fuel economy. That’s the goal anyway. Everyone has their reasons, like you said
@@CraftsmanQuad19 That's a good choice. One of these days I would like to build a 1/2 ton 4x4 step side with something like that in it. You definitely don't need a monster engine for a big truck. My dad had a F-600, can't remember the exact year early 60's I think, that had a straight 6 in it. I think it was a 260 something. Dad would put six yards of sand or gravel in it and roll down the road at 55-60mph. I drove it around the farm when we were digging the basement for the house and other times. It wasn't a tire lighter but it worked just fine.
Parent of Twins in-line 6 wont win any races (not a stock one anyway), but they do hold up and work hard. I’ve got my LS race truck and this won’t be it lol. For a daily drivable 383, would you run stock iron heads, ported stock heads, or some aluminum heads? Smaller ports generally mean better throttle response, but I’m worried those swirl port heads will choke it even at low rpm. I’m keeping the tbi setup on it
@@CraftsmanQuad19 I'm not sure about the heads. I'm not going to pretend and steer you in the wrong direction. I have tried to get that question answered myself and have gotten mixed results. I guess it depends on how hard it is going to be to work on the engine once it is in the truck. If it's not a huge issue you could put on the swirl ports and see how they do and if it seems doggy change them out. If it is going to be a PITA to work on then I would ask in the comment section and hopefully someone with a similar setup or more knowledgeable than me can give you an answer. Sorry I couldn't help.
Parent of Twins hey man no worries. I appreciate your honesty. Id love to use vortec heads if I can find a tbi intake manifold that will fit...I’m not sure such a manifold exists
PLEASE do an iron headed LT1 test. My 96 Buick Roadmaster sedan needs more power but I have almost no budget. I can do most of the work myself. I just don't know what to do.
Long tube headers first,then put on some 1.6 roller rockers,you can even get by cheaper by only using them on the intake valve,cost you half as much.
I'd say best bang for the buck would be tuning. over at gearhead-efi message board they have a way to flash the stock lt1 pcm diy without buying the expensive aftermarket software. there's a steep learning curve to tuning, but it's free to lean just lots of reading. which makes it the best thing for when you're tight on budget.
as for what to hard parts to buy first, depends on how badly you wanna make your car worse to drive. big cars usually respond to big gears and loose converters in et at the drag strip. if you just want hp, the exhaust is a good place to start, like said above, rockers would help and can be found cheap used on the boards. but how much hp they would make if you'd even feel it. I don't know. gen 2 did seem to respond to a little bigger cam pretty well, but being such a big car, without the gear, converter and exhaust. it will just lose mid tq and make it less enjoyable to drive and maybe not any faster in the 1/4.
nitrous?
As someone whose local drag strip does not do track prep some nights. I'd pick the smaller motor for a street tired car.
Yes I think with the right gearing the 4.8 could feel like it made the same torque numbers as the 454. At the drag stripe with all being the same car set up, I think the 4.8 could pass the 454 at the top end. Great comparison video, always enjoy seeing the difference technology makes on these engines.
The big block is heavier and if it doesn't launch, because cars that are heavier and make torque are hard to launch, it's over. If the 454 ever falls behind it will never catch up. The LS with the same driver in the same car will be faster every time. It will always trap better. It would likely be quicker as well.
To answer the question the 4.8 would win a drag race with both optimally geared. The 4.8 makes the same power peak but over a useable rpm it's average is higher. And that's before we discuss the weight advantage
@The Truth about Africa hurts what's so funny?
@The Truth about Africa hurts maybe you should study physics a little more.
Mario Andretti said: Horsepower sells cars torque wins races!
That doesn't mean he is correct..
If that was always the case Hondas would always get smoked
@Daver G Well dave when U have a transmission not much bigger than a school kids pencil sharpener the torque curve dives on the race track anyway. Actually less torque in a race engine is common otherwise you could find yourself in lunar orbit or a holding pattern over an airport till ya get clearance to land again. Too much torque on a race track will send ya off the track. I think the guy that could tell ya about that best would be the old man Dale. I worked a life time with race engines here and won 5 championships and what I can tell you is torque needs to kick in past 3rd gear not before.
He means racing that involves turning and braking, put a tpi third gen against a modern type r on a road course.
All for about $7. Priceless. I almost pissed myself. Richard a dang fool. Love his vids
I'd like to see 4.8 ls vs modular 4.6 sohc battle. H/c/i..example trickflow stuff
Thanks for the informational video. It wouldbe cool if you can do a video on what make model vehicle you can find what engine in. In my local salvage yards i see many of the “LS” engines but i rarely find any 454 Engines or i just don’t know what i’m looking at.
look in full size trucks and SUVs for the BBC
No replacement for displacement.
It's a pump. Replacement = add more air = forced induction.
Not always true
Since HP = torque * RPM/5252.....With the proper gearing torque at the wheels will be the same just at a different engine rpm. The bigger engine will launch faster if the same engine rpm is used for both at launch. So it would be interesting to scale the 4.8 torque and power curves by 77% rpm and line it up with the 454 curve. The ratio of displacement of the two engines (4.8/7.4) is 65%. I'm not sure why the discrepancy between the peak power ratio and displacement ratio, but maybe it has to do with the cam profile, friction loss, compression ratio, and head design. Which one has the best BSFC????
Just a random rant, my 03 Silverado has a 4.8 and I’ve always noticed that these things make almost no torque, my 99 Sierra had an 06 LQ4 swapped in and I had torque and power for days in comparison to the little 4.8, they definitely leave a lot to be desired.
They make good torque. They just make it so high in the power band. They have no low end at all. My 4.8 sings from 4K to 5.5k. But the low end is none existent.
Chuck Nasty I have an lm7 out of an 01 Yukon, I’m gonna refresh the engine and use the flat top pistons from my 4.8 with a healthy cam, TBSS intake, and hopefully source some nice 243 heads. I’m not lookin for crazy power, I just want something that can accelerate moderately for a daily. I go over a couple large bridges and on the way up my truck hates life. Eventually I’d like to throw an lsa on top but not sure how likely that is, seems that swap has become more expensive now days.
I would guess that on a manual transmission all things equal the 454 would be faster than the 4.8l. On an automatic with a 4000rpm stall the 4.8L could match the big block. in acceleration.
BBC LS6 in my 69 z28 and a 6.0 turbo in my 78 camaro love both.
Richard weird question but just say there was a planetary gear (%100 efficent or no power loss) to reduce the output rpm to about 75% of what the 4.8 runs to raise final drive torque as close to the 454s torque and test drove in same car same rearend gears and drivetrain the same.. what's your thoughts of the difference between the two motors in a drag race situation or just dyno numbers
454 is lots heavier
@@richardholdener1727 besides the weight difference
Great videos sir! Been watching them for quite awhile. I sure would love to see you one day do some testing on the old BB 396. How would it compare to equal displacement LS? Would the BB heads help it perform compared to the LS? There still seems to be plenty of 396s out there that no one is interested in buying. For a street car, hot rod, rat rod whatever fun car, it seems like people should consider it an option. Or is it just not worth it? Sure would like to see you put your twist on that kind of comparison with all those tweaks and variables you always would into those tests. Keep the great content coming!
they are hard to find
Seems they go so cheap in the big block chevy world on Facebook, nobody wants them anymore. Maybe the supply is just dried up out west where you are?
Lol 60 seconds in 7 likes 3 comments including myself ...i have tk admit it im addicted!!
it's a good thing
Hey are you gonna be able to do fresh testing? I’d like to see some comparisons of Texas speed products
fresh like the 500 Caddy? but yes on TS
If both motors. We're in the same car with drivers weight reaction times ect the same. 454 gets the jump. 4.8 come around the back end. Be a tie at the finnish line. If the planets were aligned your at sea level at low tide. And your wearing your lucky boxers.
If you gear the 454 to work from 2500-4500 rpm and the 4.8l 3500-5500 rpm both have similar hp curves between those rpm and would be similar on the strip.
I want to see if you can find a combination of all stock gm ls parts to make power at the magic10k. I’ll bet you can with a large bore destroked combination.
I don't think you'll find a stock gm cam that makes power to 10k.
john somethin I’m thinking if you can drop the displacement enough then maybe. Would be fun to see if you could get there.
Thinking about it, it would fall on its face w Inadequate valve control.
stock cam and stock springs will never get there
Richard Holdener Ok! Let’s see how fast the generals parts bin will spin! Maybe cheat w some aftermarket valve springs.
Love them both, as you said, it would depend on the application. We all know it you add a turbo the curves just move up still making the BBC more powerful. Is you go mod for mod, the BBC is STILL gonna win! Displacement will always be king for torque and power. Aw hell just get them both and enjoy your playtime!
Do like a max cheapo build. All production rotating assembly and production head castings
You need to do the 8.1 L GM
The question becomes Gen VI 454 or 8.1?
So much more aftermarket support of gen 6 and earlier big blocks that it shouldn't even be a question. Extra cubic inches is cool and all, but if you can't do anything to take advantage of em (you can't, its EXPENSIVE to make a good solid powerful 8.1), its trash. It costs an arm and a dick to make a 700hp 8.1
@@rustysausage69 That is true about the Gen V and Gen VI motors. I spent $1,900 on a kit from Summit last spring for my 93 factory 5th wheel truck. The kit was one thing and I spent another $1,000 on distributor headers & exhaust. You can get a cam heads new bolts gaskets and headers and stuff for an LS 4.8 5.3, 6.0 motors get all of that for $2,200 bucks. When rebuilding always replace the 0-2 sensors and the EGR stuff which does add about another $500 bucks but it also makes a diff when the build is done. I have a 99 New Body style extended cab SS really rare truck for one has 4.8 in her from the factory. I was pushing 300hp factory when I got her. Pulled the motor out cleaned the entire block added the Summit kit replaced the factory headers. I am push 470hp out of that 4.8 which is plenty. I can't hold it on the road past 135mph. At 135 the truck begins to like float on a cloud of air and I fear I would never be able to steer it down in an emergency so it's just for nice and sneaking up on the cholo's in their tuner cars. Just on a note on the factory Silverado those factory wheels none of em are speed rated period. Past 100mph you can get a nasty shake to the truck from the wheels. There are plenty of aftermarket wheels that also are not speed rated for going past 100mph. I found that out the hard way.
706 had porosity issues around the water jacket
For whatever this is worth, I ran a 1 ton express van with 6.0 liter LS for 450+K miles, parted out the van (keeping the eng for future swap) then bought a 2017 express for my daily runs with a 4.8 and same "road gearing". The 4.8 is nothing in power compared to the 6.0, each of these were / are all O.E,M. in the same application and this is seat of the pants results.
I would like to see a comparison between the L86 and L8T engines. I don't really get why GM made two different truck engines that make nearly identical torque and hp numbers. What parts can be taken from one to make the other better? Are they really that close in power? Can you stroke th 6.2 with the L8T crankshaft? I've got lots of questions.
8.1 ???????????
GM put lousy heads on those. Way underachieving engines.
@@spareparts7630 With nothing but a factory cam swap and different tune, the stock 8.1 did OK. www.offshoreonly.com/forums/attachments/general-q/124495d1107971433-496-mag-h-o-torque-496ho.jpg
Torque is basically one power stroke (Cid VE% CR etc..) Hp is all those power strokes added up over time. (rpm)
Why compromise? 454LS all the way!
That 454 with those numbers needs a tight converter and mid gears
It actually comes with a 3:1 torque multiplier and standard 4L80E ratios. I believe 1st is 2.52 just like a THM400.
Richard, I think you are saying it backwards; horsepower is a calculated number based on torque and rpm. So the calculated horsepower curves for these engines are a result of the dyno measured torque values over the rpm range. HP is a result of torque generated at rpm.
HP=TQ x rpm/5252
@@richardholdener1727 Yes, the only measurable quantity that ic engines can generate is torque. Horsepower is a derived quantity that comes from the formula you mention. So the fundamental real world difference in your two tested engines is the difference in the area under the two torque curves between the normal operating rpm limits. I'd certainly rather have the 7.4L torque curve for everyday driving and especially towing my boat (but maybe not the added fuel expense!).
The 4.8 would need about 50% higher numerical gearing (say 5.29 with the 4.8 vs 3.50 with the 454) and a much looser converter than the 454, but both set up properly would ET and mph basically the same. LS is also probably 150 lbs lighter
I prefer making peak power between 2500-4500 rpms in my gas engines. My vehicle applications (work truck and station wagon) do not need to be revved out higher. At this tim I have a 366TD in my C60 that does phenomenal for what the truck is used for. Even though I've flirted with the idea of swapping it for the 427TD with a bit of performance modification. My 95 Caprice wagon came with a LT1 but a swapped it out for a Gen5 454. The wagon see's 28 mpg just on the stock engine. It has a 4L80 and 3.55 gearing and a 33 inch tire.
The new ford 7.3 big block is like an LS engine, I would choose that one if I had the resources.
I don't think so. I have two Triton V-10's one in my F-350 and one in my E-350 van and they don't even come close chipped or not. Alot of it is the computers do not let them go past 4300rpm period and ya can't change the rev limiter on those computers. I don't get the throttle response like I do out of my LS trucks that just plain ole haul ass. I can't say that about some of the Ford Diesels running around here have some real nuts to em. Those Ferd coil packs they put on them Tritons and other engines suck from the get go. Also those R4L100 trans are not made for acceleration either. They hold up very well don't get me wrong but they are not built to throttle out like a chevy 4LE60's.
Nobody builds stock bigblocks tho.
I know it's the bastard motor nobody wants to talk about, but have you ever done a test on a 366 big block? I've got one out of a 78 c50 I'm going to put in a 74 c30 for a while until I'm done building the original 454, I was curious to know what kind of power they make. I really can't find any information on them at all. Just curious to see what kind of power they could make stock as well as modified
I love these type of videos mate..... I'm still holding out hope for the l67 big bang
does weight matching pistons and conrods add hp to either a stock engine or one with all the trimmings :)
p.s u need lots of torque for pulling ? how about a diesel engine ;)
that is done from the factory
@@richardholdener1727 all right . in europe stock pistons can easely have a weight difference of 4-5 grams from the lightest one to the heaviest
@@1worldgaming18 you should see how much of a difference going to a 030 over piston can do for the weight. I know they all weigh the same but it's more than youd think.
Hey Richard I was thinking about that destroke video will it work the same with a 289 crank on a 302 block? Or will the motor have no compression or will it just become a 289
It makes it a 289, they both had the same bore
You need 289, boss 302 or, and I don't know if it's true, turbo 2.3 rods, to use stock 289 pistons. Apparently the turbo 2.3l uses the C3 hi po 289 forging.
Well, if you want torque just go diesel! Perfect for towing ;) When are you going to test a 12v cummins, 24v cummins, lm5p and a powerstroke?
I have a combo for you that a lot of guys are drag racing and winning big. Rods and pistons 6.0/5.3 big turbo and big nitrous on E85 and 799 or 317 heads and meth injection and a self cam stage 2,3 or 4. And making well over 1000 hp. Is reliable and if done properly can easily be steerable if you know it's a drag car you're driving on the street. Just saying. That would be one hell of a test. How much can a good rod and pistons combo in junkyard motor handle. I think you will run out of map sensor again like on the big bang gen 4 6.0 you did. I'm sure you have the stuff laying around. Lol. Love the channel and what you do with motor trend. You need your own show on motor trend.
Transbreak an anti-lag setups will help the 4.8 a ton