its simple math, it made a peak of 450ftlbs, but carried 400ftlbs out to 8000 and barely squeaked 600. HP = torque over time. It needs a light car, a 4500+ stall and 5 something gears for it to work. Its gonna get beat by a car that weighs the same, but has that same 600hp at 5000rpm, and runs a highway gear, provided you can get it to hook, and you'll be able to drive it around easily. Vehicles are all trade offs/compromises. 700ftlbs at 4500, with 700hp at 6500 with a 3.08 gear behind it is going to run better than 700hp@9000rpm (its only 410 or so ftlbs at 9000) with a 5.13 gear behind it in a 2000lb and heavier car. Give it enough airflow and valve train stability, and anything will make hp above 5252rpm. Its how the math works. I Have a 700ftlb@4500/700hp@6000 engine it was still climbing but we stopped revving it at 6500. Thats not the peak HP. It is making 520+rwtq down at 3000rpm with a 270/272@.050 solid roller, and only 467ci. Gear it so that grunt everywhere is working to push the car, its gonna run faster than the steep geared high revving small engine that makes the same hp. Its in the math. Hero peak HP numbers are meh when there isn't any tq behind it. the 250/260@.050 cam and just enough airflow for the tiny engine is going to make all the power up top. Its math.
LDN Wholesale because RPM isn't street friendly. Anything you constantly have to shift above 6000 to get the car moving isn't really that much fun to drive. Much like THUMP ER up you'd have to have a ton of converter, I personally was thinking a 5000 or more. Give got to get that engine into it's torque curve or it's useless and as romantic as 600+go looks on paper the torque was just piss poor.
The short stroke with a long rod is used in some cases to control piston speed or acceleration within the bore and to increase dwell time at TDC when running higher RPM.
Engine Masters just did an episode where they tackle rod ratio, and sort of debunked the long vs short rod...there's no appreciable performance difference between dwell time at TDC and BDC. I'm sure there are situations where it may apply differently, but it seems like no one really has done much true testing on whether rod ratios really do matter.
@@jon2914 Teoretical difference in perofrmance - shorter rod should be little better brthing in low rpm... BUT what about longetivity ? Dont need to do any tests to know that longer rod is lighter on piston skirts... and there is much more friction in high rpm, so there is the advantage of longer rods...
@@nobodyspecial313 sure, just talking about pros of longer rods.. there has to be balance, depending on the application of course.....alot of variables
While is almost always easier, cheaper, and more effective to get more power and torque from more displacement it's often more fun to do it with more rpm.
Back when everyone was building 383SBCs (350 block/400 crank), I was always going the other way building 377SBCs (400 block/350 crank) or 351SBCs (400 block/327 crank).
One of the sweetest running engines I ever built back when was a 377 destroked 400. Flat top pistons, angled milled camel hump heads with 2.02 intake valves, and a cast iron 2 barrel intake. Don't recall what cam it had but the engine was built for a 77 Camaro in stock class circle track racing. It came from the factory with a straight 6 and a 3 speed standard. I don't recall the rear gear ratio, but it was perfect running in second gear. It won the championship the year I raced it and it very seldom finished in second place. That camaro was so fast that everyone wanted to protest it but no one wanted to put up the money to see what motor I had built. Made me a believer in them destrokers!!!
alot of people use the 350 block because the walls are thicker then the 400 so it helps with heat. 400 crank in 350 block is 377, 30 over is 383, 40 over 385, 60 over 388 cubic inches. the 400 block had steam holes which with the thinner walls would crack the walls in the 400 block. lots of 350 blocks vs 400 so it was more "common" then to use the 350 block.
That was my motor back in the day when everyone was going 383 instead my poor ass was building back yard 377 with solid cam and camel hump heads kicking everyone's butt
Hrmm. The destroker with the stock cam has a curve that looks like one hell of a cheap, flexible road racing engine. Better rod/stroke ratio keeps piston speed down and avoids essentially cramming the piston into the side of the chamber as well at mid-stroke... it'll live longer.
Thanks cause everything i thought that i knew became confusing after watching this video but what your saying brings me back to reality and what i always understood to be correct
Another reason for short stroke large bore engines is to keep piston speeds lower. F1 piston speeds are lower than some high RPM LS builds because of how short the stroke is.
@Daver G A stock 5.3 at 3.62 inches of stroke revving to 8k is 4830fps, 5200fps on a 5.3 crank is 8614 rpm. 5200fps in the 7L LS at 4 inch stroke is 7800 rpm for comparison
Short stroke with short rod will have increased piston speeds. Short stroke with longer rod will make mean piston speed slower and reduce side loading on the piston. The ideal stroke to rod ratio is 1.7:1-2.0:1. Also with a longer rod on the same deck height you’ll have to run a shorter compression height piston.
@@ianmatteson482 I think you mean peak piston speed not mean piston speed. Mean piston speed will be the same for motors having the same stoke at the same RPM regardless of rod to stroke ratio. Shorter rods (same stoke) means the piston travels faster for the first 90 deg (from TDC) and slower for the last 90.
This Ford guy is convinced. Ported stock cathedral ports, the BTR cam, and twin Ebay turbos to fill in the bottom end. The shorter stroke is also less stress on the engine. This would be super cheap and reliable, and so much fun to drive.
You've completely(well not entirely) skipped over why race teams run a shorter stroke. Piston velocity. You want to keep it below ~26m/s. With the short stroke at 7800 rpm you're at a safe 21.6m/s. That same RPM at a 4" stroke is 26.4m/s. Not good for longevity unless you're a F1 team. As a compare, the 20k F1 V10's you reference had a piston velocity of 26.5m/s at 20k RPM. This is the reason for a short stroke, material strength/longevity.
Good point! I was waiting for him to mention ousting speed but he never did. There is a theoretical safe limit for piston speed or at least there was when I was studying engine design years ago.
Yes and no. The big bore allows for more valve area to accomodate the flowrate to make power at those high revs. The short stroke thus allows more bore, obviously, but with it that lower pistons speed. The old rule of thumb of 25m/s mean piston speed isn't as accurate anymore as piston and more so piston ring technology has improved. You'll also notice that if you're concern was internal stresses, the mean piston speed doesn't show the real stresses like breaking down and deriving instantaneous displacement (travel in the bore), then instantaneous velocities, and then instantaneous accelerations. The latter is where you really start to get forces on bolts, rods, piston bosses, wrist pins. In reality, it's a balance of the two, like most design criteria of an ICE.
@@thirteentwentyfeet and they only see that for a fraction of a second before they rebuild them. They also probably don't have to be too worried about ring sealing (blowby) efficiency at that point.
This is literally what nascar cup guys have been saying for years, Baja, and anyone else with long lasting high RPM engines.. valvetrain stability, hence the reason for pneumatic valve control in F1...
@@KaoticFdr1 Freevalve is dead in the water. We don't need to reinvent the wheel when we have finger follower style DOHC and even variable valve timing.
A high winding small block screaming at 8k+ rpm is like angelic music. With a cam that big in such a small engine, I bet the idle sounded wicked. As much as I like the sound of a strung out V8, I like brutal torque curves that let me lope along down the road. Either way, I suppose I like engines than make transmissions cry. They’re either gonna strain from sheer grunt, or be unhappy from rpm. Thanks for all the info you provide.
Where most guys screw up is they dont take advantage of unshrouding the intake valve on the bigger bore. If you scribe the head to the cylinder and grind the combustion chamber around the poor flowing side of the intake valve, you always make far more power than the power you will make simply by adding the extra cubes from boring it. This is why a chevy 305 could never make as much power as a 350. The smaller bore 305 puts the edge of the intake valve too close to the edge of the cylinder, severely limiting the amount of air you can get into the cylinder, not to mention you cant run as big a valve with the smaller cylinder, or the edge of the intake valve hits the edge of the cylinder.
@@donrutter6765 i only mentioned the replacement for displacement thing because it's an argument that's as old as Time. Engine is simply an air pump. Its goal is to move air and mix it with fuel it don't matter how you move the air,as long as you move the same amount of air you will create the same amount of power. Rpm is the direct replacement of displacement because all you have to do is add RPM to move more air. With more cubic inches you don't need as many RPM to move the air.
Ricard, love the stuff you present here. I was shaking my head through this whole video until the last part. I have been building engines and cars for over 50 years and when talking to someone that wants an engine built that "really runs" the hardest thing for them to understand is bore/stroke ratio, bore size and intended usage and RPM as far as breathing goes. I would like to see this test with a different cam optimized for a 6500 RPM limit and cathedral port heads sized for the air flow. Bigger isn't always better. ( In case you didn't guess my focus is street engines, I think you understand with racing engines there are no limits.)
I run my lq9 to 7800 rpm. It sure sounds sweet up there. Been doing it for 6 years now. The crazy thing is it’s unbalanced, lq4 block and crank, ls2 pistons and rods, ls3 heads and a decent enough camshaft. You are right though it’s all valve control.
The thrust angle reduces with either a smaller stroke or a longer rod, this also affects friction on the sides of the pistons but it also reduces the distance and weight that the engine has to throw around which allows it to rev easier
My buddies dad in the 70's used to race a 266 cubic inch small block chevy and he left the line at about 11,500 RPM's, He had $10k just in heads (back then).
I have to tell you Richard that I've always been planning on doing an TT LS for my 84 Vette and couldn't find as in depth of combinations to research until I stumbled across your channel. I absolutely love what you're doing it's awesome. I've learned so much from you that I 110% know exactly what I'm going to do. Thank you for your time and dedication for passing on knowledge. Top notch content. All the best your friend Ed from Canada
It's unfortunate that LS7, GMPP LSx and/or Re-Sleeved blocks are so expensive, because I would LOVE to see the 3.62 factory crankshaft stuffed into either a 4.125" or even 4.185" block and rev'd to the moon.
i cant get the image of ( A T-Rex with short little arms trying to run the Dyno controls with a LS in the background with turbos glowing red) out of my head after reading that shirt. lol.
HOLY CRAP RICHARD !! Do you ever sleep ? You are AWESOME ! Thank you so much for doing all this testing, I know first hand how much work this is. I never had the opportunity to do that much testing with my dyno. thanks again for working your ASS off to educate us !
DBSSTEELER agreed, piston velocity is the underlying limiting factor. The force required to accelerate the mass of the piston is a function of velocity^2. Eventually the force from repeatedly reversing said velocity will exceed the material properties of the engine components and destroy the assembly. Friction adds to the mess by generating heat that breaks down material properties and lubricants.
Richard Holdener, first off I enjoy your channel. Also, I agree that valve train stability is a huge factor at high frequency/rpm. I agree that some engine designs use what I consider very high piston velocity and still hold together. However to highlight the variable of piston velocity, I’d like you to show an example of multiple engines with different bores and strokes operating at the same power level and compare the fuel consumption. I hypothesize that in most cases the engine with the lowest piston velocity at the same power output uses the least fuel.
Parts have gotten much better over the years. Which allows us more RPM and piston speed before we see breakage. Also, valvetrain is by far the most important thing to me. As light as possible! Stability is huge!
@@richardholdener1727 what stops mountain motors from turning over 8200 is piston speed not the valvetrain. I own a 650cuin 5" bore center Hemi, exact same as mountain motors turn mine 9400rpm with ease. Same valvetrain bug the 820cuin falls hard on it's face over 8200 due to piston speed. My destroked version has no issue.
Thanks for doing this. My father explained when I was a kid how they did this to FlatHead Fords back in the 60s. They raced dirt track and figure 8. 😂 he said the engines had less CU but faster rap-up into high rpm range. Something not really measured on dynos. How fast the engine gets from idle to max rpm especially under load.😂
In my understanding, in racing, motor displacement Is often regulated and max rpm is not. Large bore gives more room for larger valves, thus being able to breathe more.
glad you explained its not stroke or bore, its displacement, so many do not understand this when 383, stroked 350, got popular so many would say stroking adds torque not hp, but didn't understand the reason was that more displacement increases torque but peak is at a lower rpm, since hp is rpm dependent it doesn't seen to increase, but if people realized that with bigger displacement you can now run more duration and therefore lift for the same idle loppiness, they'd realize stoking enable much higher torque and hp and the hp gains were there by going bigger cam. in the end if you stroked and cam'd to keep peak torque at same rpm as before you would have higher torque and hp
THANK YOU FOR THIS!!! As someone who's a gearhead first, then a Ford guy, this "destroked" BS has always driven me INSANE. 5.4l Modular stroke - 4.165" 7.5l(460) BBF stroke - 3.850" Guys can argue all they want about "short stroke/high RPM" - I'll wait for ANYONE to try to tell me that a 460 big block is a "higher RPM engine"(whatever that even means) than a 5.4l Modular ...again, a 330" mod motor has a *0.315" LONGER* stroke than a 460" BIG BLOCK - and people spin these things up to 9000RPM on the drag strip
I’ve had the same argument for years. Very frustrating. Good old boys that really do not understand basic engine theory will always cry BS. The bottom line is that cylinder head, camshaft, and intake manifold runner length/cross section pretty much entirely dictate the RPM range of an engine. Bore to stroke ratio is a very unimportant, secondary metric to know - as long as the cylinder head can adequately feed the displacement. Smaller bores limit potential valve area, especially in 2V wedge setups, but the 4V cylinder head really throws a wrench into that. The GT headed 5.4 4V is an excellent example of an outstanding pair of large/raised port 4V cylinder heads feeding a very under-square (3.552x4.165) 330 ci V8 and it loves the rev. Go figure. Those same heads still love to rev on the larger bore 5.8 too (3.681x4.165) because there still isn’t any cylinder head limitation at 354 ci. The GT500’s twin 37mm intake valves provide nearly as much effective valve area as an LS3’s 2.165” intake valve does, and it fits them onto a 3.552” bore without valve shrouding concerns and MUCH better intake port geometry. So we get a very undersquare engine that’ll rev its ass off, makes a ton of power easily and laughs in the face of every Smokey Yunick quoter on the interwebs.
@@BC08 Yup, nailed it! Valve area is KING, plain and simple! Obviously there's a bit more to it than that, but B vs S isn't one of them. Bore your junk as much as your block can reasonably handle, and then drop the largest stroke in that will take displacement up to the edge of class limits - then stop wasting your time on the short block and invest it into what really affects your engine output and the curve; the top end It's like people are oblivious to all of these aftermarket blocks going larger and larger with bore spacing, 5.0" all the way up to 5.3" - NOT deck height! I wonder why...
BTW, Freiburger & Co just completely busted the rod ratio bullshit myth too on the 'Engine Masters' show on MTOD - short rod or long rod, it averages out. Rod ratio is important for reducing piston side loading/cylinder wall wear(short rods = steep angles = increased side loading) - but not for power production
Richard Preach brother, I've got a 305 that was done back in 92 when I came back from Desert Storm and punched it out to a 331 and went through 5 transmissions...lol in my 68 El Camino....still got it and it's still running that same 305 today...I appreciate your videos and outlook on the LS engines too.
Richard, it would be really great if you could make a video comparing a change in 5.3 valve lift only. Keep duration the same and creep up on lift to the point of diminishing return. Maybe you could use a change in rocker ratio to make it easier. Great videos!
I dont think its that it likes to rev as much as it is it has to rev to make peak power! No reason to be mad, just really good knowledge from a knowledgeable guy
I wanted to do what you are doing ten years ago! Right after I finished up at SAM Racing( School of Automotive Machinists in Houston TX). I enjoy this channel much more than you and the comp channel!
Junkyard LQ9, cam/valvetrain, check bearings - 150shot. 550whp Cheap cheap cheap - 1500$ cost for me to build one so it’s REPEATABLE! And if my upgrade parts survive, the costs drop even more. Stock lifters because I try not to remove the heads or stock bolts/gaskets, so we spin it to 6800-7400 rpms to stay safe. Stock ring gap because I never removed the pistons. 12 events on this current one. I love thinking about cool builds but my pocket forces me to stay closer to stock. Also with a lightweight triple disk on that engine.. it revs up SO FAST! I would love to have a LS that could rev past 8k though :)
@@reyperez3424 no I didn’t. Also as a side note, I didn’t want to do it for power, I wanted to do it for sustained high rpm longevity due to the decrease in connecting rod angle
Cool build! I remember one of the famous car magazines tested the stock bottom end of a 5.3 engine to see how much power would break it. I'm talking turbocharged, high-flow heads, they threw it all at it. Long story short, they quit at 1400hp and the stock bottom end was little worse for the wear if at all. It was during disassembly to check the rotating assembly that they discovered the 5.3 was actually a 4.8 - 1400hp from a stock 4.8. So, piston acceleration is reduced with an oversquare build like this too. Of course like you mentioned the valvetrain is still the weaker link, but that slower acceleration/deceleration compresses the fuel mixture more gently, to the point that you can run higher compression with no side effects. Hot Rod Magazine once built a 352 from a 400 with a 327 crank and modified Ford 300 6-cyl rods. They ran 12.5:1 pistons on 87-octane with ZERO ping, and the engine put down 412hp.
This engine would be perfect for a lightweight chassis. Put this in something like a Miata with a manual trans, and grin ear to ear while banging gears at 8k!
I have two mid-engine cars. One is a 1987 Fiero GT 5 speed with a L44 2.8L V6 that made approximately 140hp at 5200 rpm and 170lbs of torque at 3,600 rpm . The Fiero weighs 2,780 lbs. The other is a 2000 MR2 Spyder 5 speed with a 1ZZ FE 1.8L that made 140hp at 6,400 rpm and 126 lbs of torque at 4,400 rpm. The MR2 weighs 2195lbs. The MR2 feels like a go-kart compared to the much heavier Fiero. Because the 1ZZ makes it's power at a far higher rpm the MR2 is able to be geared lower making the car accelerate even faster. Also because the engine is designed for higher rpm this enables the car to reach a higher top speed of 135 mph compared to the Fiero's 120 mph. When the L44 is peaking out the 1ZZ is just getting started and makes good power all the way to 7000 rpm. What's funny is the Fiero, even though it is a heavier car it's engine pulls harder at a much lower rpm this makes the car feel more powerful off the line. The MR2 feels like it's got nothing off the line even though it's a significantly lighter car with lower gearing. Torque is about leverage horsepower is about the amount of work done. So in this example you have two engines with a drastic difference in displacement yet make the same horsepower but do it in different ways. The MR2 and the Fiero accelerate off the line at nearly the same rate. But after first gear it's all MR2 from second gear on the MR2 continues to pull away.
I run a Turbo big bore 4.8 in my drag car. We've been 4.90's @ 143 mph at 2800#. Stock 243 heads, TBSS intake and a baby 80mm turbo. The short stroke really keeps the turbine wheel happy
I like his videos, he always has an open view never saying what he says is right. There are options, and at the same time he gives you great information......
I got less money in my set up than you think. A installed set of kooks on a s550 at a shop cost more than I have in my set up and I got some really nice parts. I built street/race cars for a living for 3 years in Houston before I moved to NC so I got a shit ton of awesome exspensive parts for nothing or really cheap. I got a super victor intake for 50$ and a BTR huge cam for 20$ brand new in the box and I bartered the machine work for parts and time. I got a 8-9000$ engine for next to nothing.
I’ll make 550hp at the crank at bare minimum and then it’s set up to spray so I’m gona throw 500shot at it. I’ve thrown 500shots on stock 5.3’s and they lived so I think I’ll do pretty good with my set up
As much as I love the details of the dyno testing, your summations at the close often make me rethink things I thought were "written in stone". this one was surely one of those! Your summation not only said this was true but explained why- and the little light in my "old skool small block" brain almost burned out! I've actually rebuilt several 5 and 10 hp air compressors- I know from the fingertips how accurate your comment "it's just a big air pump is", and I never made that jump. Thank you!
I’d love to see you find the best valvetrain/bore/stroke combination to see how high you can rev an ls.... affordably. You would probably have a head start with all of the experimenting you’ve done on these engines.
Affordably has very different meaning to different people so its not a realistic criteria. Even if 2 people have the same job and make exactly the same income what they consider affordable will be vastly different. If cost is a major factor stock is always a solid option.
+1 to all the comments about reliability/durability. Always like to point out Honda engines when it comes to RPM. You can rev a 4" stroke K24 to well past 9000 rpm without breaking the crank, just like a 3.5" stroke K20. But that K24 will wear out a lot faster, in no small part to the side loading on the bores. You'll egg those things out very quick. Fine for a race motor that sees regular rebuilds, not so much for anything else.
I’m like a kid sitting here waiting for the next video to come on that he makes like waiting for ups to come with the parts you just ordered for your car as I stare out the window when the truck pulls up
@@andyharman3022 I met him twice and had short conversations between races. I dont about all of his motors but I do know that the 351 Cleveland he had in the Fairmont that went undefeated for a whole calendar year was destroked to a 330 but when they moved up to the Big Blocks I have no idea what he did to his Boss 429 Motors but whatever it was it was evidently better than what everybody else was doing.
@@davescbradiorepair8195 Cool story! Being a Chevy guy, Glidden was the guy I loved to hate back in the day, because he kept beating up on the Chevies. I remember his crash in the T-bird during the big-block era. He got out of the car, and immediately put his jacket over the intake manifold.
thanks mate! im wanting to put a 4.8 crank in my 5.7 to move the power range further up in the RPMs, seems as though this should be achievable as long as the valvetrain suits.
lol I have gone from does he know what he's talking about, to yes he does and being totally addicted to your videos. I'm now down to checking daily for new content. Way to go Richard that takes some doing.
@@richardholdener1727 no problems, it's actually a real relief / pleasure to find YT channels that really know what they are talking about. There are more than a few really popular YT channels with a million plus subscribers that are completely clueless, and they carry on like they are some kind of authority on the subject. Pisses me off know end that they are misleading so many young guys and gals into thinking that what they are saying is even remotely factual. I think the first video or two of yours I stopped and thought hmm not sure if that is exactly right, gave it a bit more thought and decided nope you were right. It's just a real joy to be able to enjoy the content without having to think are they right?, or worse full of crap. Keep up the great work you earned a new subscriber yesterday.
Well this is why I love my 409 Chevy. Short stroke big bore. Pulls like a big block revs like small block. But very little down low. BTW not a 409 sbc or LS. A real 409
Where the short stroke engines really shine is oval track racing. Being able to sustain high rpms for long periods of time. Piston and rod speed come into play. A longer stroke engines has a lot more strain on bearings, con rods, and crank. Simply because it has to travel farther on the larger circle path of the crank. It's all about reliability at high rpms. The valve train definitely effects the rpm range but the piston/rod speed kills stroker motors. I have seen broken cranks and lots of spun bearings. 377 vs 383 sbc 377 is more reliable.
My friend had a few 1968 and 1969 Camaros. He had the 302 and a 396. He always said the 302 screamed but it couldn't hold a candle to the Big Block 396! No replacement for displacement. He passed away last year. I miss him.
Yep, make your body take up lots of space with violent hand motions that pop your veins out nicely. BTW Is Richard the guy from "pinks" or the henchman from House of Cards?
I figured valve float would be the thing that limited it, just saved some of us from trying this. If nothing else the longer stroke gives you more reliable HP, as opposed to revving it into the stratosphere.
It is pretty simple more displacement yields higher port flow if port size does not change. You simply get ideal port flow at a lower rpm with more displacement creating torque sooner and port velocity reaches choke at a lower rpm causing hp to peak sooner. F1 utilizes the combo they use because it fits within the rules.
Interesting. I thought that for endurance racing piston speed is a major determinant in engine life and that was one of the reasons that even in classes where valve size is limited or the class requires factory heads that people fit larger bores and short strokes for the same displacement.
I dont think I've seen anything on flat planes. Most certainly haven't seen one on boost. Just a thought. Thanks for this test and all the others. You rock man.
I would love to see an equal comparison with the Rec heads! I'm actually wanting to put the same combination together for my E36 that's setup for time attack! I want this combination because of the linear torque range, my BMW weighs sub 2000 pounds. My first E36 had an L99 and was great for drifting but could be a handful on a road course! I believe this combination would be a great setup for a road course car, maybe it's just me haha
You have the best job in the world. You get to beat the balls off engines on a dyno Seems like any type of combination we can think of with good info for all of us. Thanks
I couldn't agree more with the points made here, Short stroke with long rods is simply to lower the rod angle and decrease the amount of piston acceleration and deceleration, thus introducing less stress on the rods at both ends, ALLOWING the engine to rev higher. Higher revs opens up the potential to make more power i.e, more design rpm total, hence why NASCAR engines have been designed to turn as high as 11k rpm. Along with power higher in in the engines rpm is the ability to design a more broad curve over a larger window of rpm, meaning an engine built to turn say 12k can have the potential to make more than usable power from say 5k to 11k, and within that window to avg a higher hp number, than a lower reving counterpart, while still not suffering too much loss from 3k to 5k. Well stated and very informative.
I would love to see build comparisons that show the fuel efficiency relationships on engines between factors like hp per c.i., etc. As in, will a 500 hp NA 4.8 consume less fuel than a 500 hp 5.3 or 6 liter. The reason I'm curious about this is everyone k ows how hard on fuel 6 liter LS engines are compared to 4.8's and 5.3's in stock trim with no REAL seat of the pants difference. In other words, what's the most fuel efficient xxx hp engine comparatively? Love all the hard work you're putting into these videos Richard. Thanks!
I know this is a super late reply, but out of all three, with all other things being equal, it'd probably be a close race between the 5.3 and the 4.8l, with the 5.3 probably edging out the win by a relatively small margin (we'll say it's 400hp) What I'm basing my opinion on is parasitic loss and internal drag from engine components. Piston rings, bearing surface area, oil pump efficiency, etc. should all factor in to how efficient an engine package is. smaller diameter rings (and possibly smaller thickness if going for some really special low-tension 0.7/0.7/1.3mm ring packages), along with things like a high-duration/low lift cam (less parasitic loss due to a lower spring pressure to overcome) should be able to decrease the static rotating torque the engine has to overcome to continue rotating. typical smallblock chevy's would require around 20 lb-ft to rotate with a wrench. going to the absolute extreme with the above ring package on an LS with all the fancy bearings and a cam fitting the profile stated above netted just under 10 lb-ft to rotate. Might be nothing, might be something.
Fastest car i ever rode in had a 377. 400 block with a 350 stroke crank. It hit 8000rpm with ease. It had a set of springs between the heads and lifters to keep them from bouncing on the cam.
I would love this combo swapped in to my BMW e36. Keep the bottom end torque low to save on my drivetrain components and give me high-revving top end power.
so i came across this video again. it made me think. you brought up displacement, not bore or stroke dictate power. i agree. your example of the 3 engines where the only difference is (hopefully) displacement gave me a good idea. a standard 5.3 (3.78 bore * 3.62 stroke) vs a destroked 6.0 (4 bore * 3.27 stroke). that puts the displacement with 3ci of each other. the other thing that could be done, like one of your newer videos, is to degree the cam in. then we could see if you could get the power peaks to roughly the same rpm to see what it does on power production across the whole range.
F1 also uses a short stroke for forced indiction stability and minimizing sidewall frictional power loss and heat. The short stroke 6.2L solid roller setup I talked to a guy about at the drag strip was turning 9200rpm and had 13:1 compression and NICE ported and filled combustion chamber ls3 heads Idk what power he was making, but that thing sounded AMAZING
This is the way I've always looked at it, it doesn't like to Rev, it has to Rev. To boil it down simply, making power is about moving air through an engine. You can move a larger volume of air by changing three basic variables. Displacement Aspiration RPM A stroked, oversquare 5.3, would do the literal opposite, make a big number, at a low Rpm.
Dont forget, a larger cylinder allows you to unshroud the edge of the intake valve, and allows you to run a larger intake valve. The biggest advantage in a bigger bore is unshrouding the intake valve, not in the amount of cubic inches you gain.
You basically made an LS version of the Grubb Worm's lt1. I would love to see your breakdown of that motor. Thing is doing stuff never thought of by a gen 2 lt1.
Several years ago, I believe it was Golen Engines did a rebuild/dyno of a real deal 69 DZ 302. I remember showing my father the results... he was in disbelief. I think it only made 286 HP with stock manifolds, etc. It actually picked up power with a smaller carburetor. And they added headers, I believe after all that it barely topped 325 HP on the dyno. He was a 19yr old kid when those cars were new, and he owned one in the early 70s. That test basically threw everything he knew out the window.
I built reproductions of the DZ302, L76, L84, LT1, L79, L46 and L82, as well as HiPo 289, Shelby 289, Boss 302, 351CJ and Boss 351-all on the dyno to get real numbers-I need to do a video series-maybe with Uncle Tony's Garage-Hey Tony!
@@richardholdener1727 - please do! Even though the new stuff makes more power for the most part... the "old stuff" is still cool. I LOVE the Pure Stock and FAST series stuff. They do more with less.
A decent enough cam/spring combo in a stock 6.0 will send it to the moon rpm wise too. I think the short stroke thing is more about piston speed and friction than more rpm. Lower piston speed and less rod angle would help the engine survive longer and create a more reliable engine at big rpm. My 2c.
until you drop a valve or the needle bearings let loose.. top end is weak over 7k for track use on an LS3. I have a dry sump and lot of the top end mods incl link bars and won't go over 7k.
Man that was great info! I totally Believed the hype on the destroked motor combo’s. Thank you for the knowledge!! I look forward to everyone of these videos!
I still love this engine, id been wanting to do a high revving, destroked 6.0 twin turbo engine similar to this for awhile. Something to drop in a lighter 2600-2800lb car. I had a couple reasons for it, esp since it's meant to be a street/strip(daily driver). 1)I wanted less torque down low. 2) Airflow=able to use ls3 heads(unported) w upgraded springs/valves etc. Most importantly, just to do something not everyone and their mother is doing. I always liked engines like the dz302. Now im not a professional engine builder, for me it's a hobby. With the 6.0 w 3.26 crank still has enough torque down low outta boost , to daily it when I want to. I also figured w the shorter stroke under boost, itd def help w longevity. Anyway, i do have a question though, specifically regarding pistons. 1)You said you went with custom instead of off the shelf pistons, im guessing it was cuz of balancing? 2) You also went with 11.2+(?) Compression, was that solely cuz u also planned to run it NA? 3) Cuz I'm trying to keep it 9.0-9.5compression max to not have a problem running 89-93octane on low boost(6-8psi),93 w octane booster and water/meth for high boost (14-16psi). Do u see any issues or what r your thoughts on it? Im here in Connecticut where we do get the occasional snow etc. Granted i prob wouldn't take it out in too much but at least would like it to be possible, main reason i liked the lower torque down low. Anyway, I soooo envy your job, been following a lot of what u do w LS's, K24's etc. I ve actually got this build article saved from a while back (hotrod i think), b4 i ever stumbled onto ur youtube videos/engine masters. Im always looking up dif build's/engines n ill swear, like 60-70% of them turn out were done/tested by you.lol. sooo want ur job. Anyway, keep up the awesome work
There are often times in circle track racing when this low bottom end torque type of motor would be beneficial. I'd like to see this build with a 6.0 steel block and a distributor ignition a lot of track rules require those two things. Thanks for the great content.
