N/A high rpm V8 is just beautiful to listen to.

Excellent content. I look forward to these videos because you run tests that I have been thinking about for years.

I’ve learned SO much from you, RH. Thank you!

I've always liked the idea of a de-stroked 6.0 because that works out 329ci (5.4l). I'd love to see a build comparison between the standard 5.3 and a 5.4 using all the same parts. Every time I've seen a comparison, they change parts. Seeing the difference between small bore/long stroke vs a big bore/short stroke with the same exact parts would be very informative.

I like that you're pushing the boundaries of what we normally see.

This is literally the question of the century for us all haha! Definitely holding onto this info and combinations!

1st gen CSB were always known for there hp to torque curve ! And there are ls engines reving to 11,000+ ! Love the videos !

! Thanks Richard you are educating Mercia .

The 347 needed a custom Bullet cam, more compression and port that intake. I bet you would not only find your 8k peak, but quite a bit more HP.

Everything you do and show all of us. Your just an amazing guy.. Thank you for sharring all of your teachings and info.. Can you please do camshaft swaps. On a jeep 4.0. Stock vs the world or sumthing like that. Thank YOU

Richard Holdener I absolutely love your videos and have learned more than I ever could have expected prior to watching these beautifully intellectual engineering experiments and demonstrations. However with all that you have taught me I still have a desire to see a destroked ls hit 10k rpm with boost. I know you say its more about valve train than stroke but I unfortunately brood so much on the thought of where it would matter or become influential in a build of sheer desire and insanity. P.S. I've also always been interested in what an American meat and potatoes mentality could do to a 1UZ early gen motor. Love your videos!! Thank you for everything

Thanks for thee quiz RH. My guess is the rod length to stroke ratio is the one thing that made these engines do what they did and thanks for showing once again that you don't need rec port heads to make power. Your awesome man keep up the good testing.

Not always about the lift. It is important but lobe design is very important. A conversation with the camshaft designer may prove fruitful. Having them examine all the valvetrain components may show needs for change/ improvement in valvetrain configuration. Even though you did not mention any problems ,Would a stud girdle help to improve valve train stability? Could valvetrain harmonics be an issue? Lot more questions than helpful suggestions. As always you make people exercise their brains. That’s a good thing. Love your videos, even though my three brains cells are sometimes tired after watching them.

Back when Freiberger had all his hair still, I built a 302 with a magnum 270 cam, matched springs and early 70’s 351w heads. I also adjusted the lifters with a little less preload to try and prevent pump up (my own idea, based on some tech articles in hot rod) and was rewarded with a rev range that I calculated (no tach in the car) went up around 7500-7800 rpm. I doubt it was making great power up there, but it was sure fun.

It's time to go to 9200 RPM! Solid roller 3-in stroke 9200 the bore size doesn't matter. The bigger the better.

great testing .I will never have a engine that goes there ,but good insight to lifter tech

Why no tunnel ram and duel quads and multiple cams on the SBF?

Love this info. It's very helpfull to me and many others

I built a 1972 Dodge Challenger with a 383 bored thirty over. I ran Roads lifters, they were hydrolic but acted like a solid and I had all the good stuff in it. 86 cc chamber 440 heads with the 6 pack exhaust manifolds $$$$ windage tray crank scraper, you name it this motor had it. I used Keith Black hyperutectic pistons with Sealed Gap Chromally rings. When that motor got around 35,000 miles on it finally felt broke in and was rockin. 3 angle valve grind, with titanium keepers and stainless valves. It was also a 1965 383 block with higher nickel content. It sounded so good with 3 inch true duals. I never did get an x pipe, I couldn't keep the exhaust on it from crappy muffler shops. It would pull the front tires on a good surface. I don't ever hear of anyone using those Roads Lifters, or the Sealed Gap Chromally rings? That was in the 90's I worked for Mono lite Racing Team and we had Aries motors, 8.3 liter and 10 liter for the 300 inch wheelbase dragster and 120 inch wheelbase funny cars. This was Exabition Racing then. The old man was the original maker for all the fiberglass hood scoops and fender flares for Dodge in the late 60's and 70 and 80's. All the light weight parts like fenders and hoods and doors and trunk lids made of fiberglass. He was the man. Anyways I knew all the tricks for those Mopars then. It would do 11.60 quarter miles. But would still go 155 is as far as I took it one time on 4 drum brakes lol yippy Skippy !

what happened to the dyno runs? I'd love to hear these things hit 8k...but like always, Great Video.

I remember reading about a 289 cobra from a company called motion performance back in the late sixties/early seventies that would blast through the traps at ten thousand rpm. Still see a few mustangs on you tube with those small block fords winding past 9000, and man do they sound sweet.

I would love to see a series on the ford alphabet cams... maybe with a set of AFR 185’s or comparable trick flows. Cool to see what’s possible with a junkyard 5.0L

Fabulous video as usual Richard, I would love to know why the Ford was such an uninspiring thing, my guess would be that the single carb inlet was choke point, at those flow rates it doesn’t take much restriction to starve half the stroke.

Thanks Richard for consistently great tests and info! That Ford had all the right parts to scream AND make big power, except for the headers. They choked it right down. Should have had 1 7/8" minimum. I have a 302 SBC with similar cam specs. ( solid lifter ) with ported bowtie heads, shortened tunnel ram, 2 center shooters, and 1 7/8" headers. Pulls hard from 3500 to 8000 while making well over 600 and 450. I think that Ford was a classic example of a choke in the system. Keep up the great work.

I agree I'm really surprised that the 347 didn't make more power. It would be interesting to see what would happen with other sets of heads like D3 High ports just to see if that would make any difference.

Always learn something from your research and testing. Great job and thank you again. I really didn't think it would work, you proved it can be done.

On the SBF I'd pull the valve cover off to see if you are getting the lift as advertised. A miss stamped cam or rocker arms ratio are nearly impossible to tell by sight alone and many cams share the same lobe centers when dialing them in. A simple valve lift measurement will be your first clue. These high rpm motors are the best candidates for testing rocker arm ratios. Although higher lift may not show an increase on the flow bench they will hold the valve opened longer at and over it's maximum flow.

Thank your effort’s of so many

My 331 with the xfi cam and 10.6 comp afr 225 kooks headers my ported parker aed 650e stock block made 585hp and 462tq. Had behive springs and cheap shaft rockers 1.73 motor sport lifters. Off shelf probe rotating. Went a 5.98 8th in a heavy fox with a 175 hit on fb and 26 10.5 dots 1.32 60s

Richard recently did a cam LSA video on a 500HP combo with 108, 112 and 120 LSA. The 112 LSA made up to 34 more ft-lb to 5400 than the 120 LSA then it matched it after that. The 108 LSA made 14 more ft-lb over the 112 LSA to 5400 and matched it and then at the last 500 rpm made 7 more HP... It showed sometimes wide lsa is certainly "wrong" and the tight lsa is the right way to go. N/A cars seem to make more power with tighter lsa's.

This was pretty cool I didn't know you could get away with those revs and lifters

The two factors that used to affect hi RPM long stroke crank combos, was the weight and the oiling ability of the bigger journals. The factory OEM big stroke cranks of course had a lot of meat in the "cheeks" and balance weights. The other issue is the large mains needed for crank overlap to keep the strength of the crank. Now the "overseas" aftermarket cast iron cranks are as strong as the old OEM forged cranks. So, technology has outpaced the wives' tales.

Great info. Very interested in moving up the red-line and your test does prove it can be done with hydraulic lifters. I would still go solid for anything I intended to run north of 7K regularly or for sustained periods. I am fairly sure there is no such think as a 8K pushrod engine that can be treated as if maintenance is not needed regularly like an OEM 100,000 mile design life beater engine. I have been bookmarking and saving info on higher RPM builds for some time. There is a great article from 2010 I keep revisiting. It features pictures of dark daired dude working on a good old high RPM SBC 302.. you guys might be familiar with it.

This test speaks to me. I am assembling a 388" LS7 shortblock this week that will be Hyd roller. The cam & intake manifold set up should make peak power around 7500 and will be shifted around 8k. This engine size has been done many times before but most of them have solid rollers. Theoretically I'll need to spin this combo 10% higher than a 427" (all things being equal) to make equal power.

"Not trying to make NASCAR levels of power".... now that you mention it, any chance of you playing with a 358 anytime?

Richard, you should build a Low Lash Solid Roller LS setup for testing like this. That would be a great watch

as usual, great info Richard, I'm kinda hooked on solid roller cams myself (see below)

my 358ci sbc gen 1 with a solid roller pulls strong past 8000rpms (knife edge crank, billet main caps, aluminum rods, 12+ to 1 comp. massively ported 492 angle plug heads, .600" lift cam), fun little street engine

Without you Rich a lot of builds wouldn't be established today with that being said,,, you should do a 454 or some other Big Block hydraulic roller cam to see if it can go to 8,000rpm as well... Great information as always 💪🏾💪🏻💪

One thing that speaks volumes to me as a Ford guy primarily I love chevy to , owned both from vettes and Camaros to foxbody sto s550s to vans and trucks. If you want to go fast with a STOCK block go chevy , if you want to go fast with a Ford , buy an aftermarket block the 351w can take some power but not as much as a LS. Chime in if I’m wrong or right I’m thinking of building the famous Budget 418. A 351w stroker Google it. 670 crank hp NA on pump gas. The perfect street strip engine. With some boost this combo would be a monster just on low boost. Only thing I MAY change on the build is the dish pistons to flat top with valve reliefs and different rings. 10.5.1 to 11.5.1 wold be perfect. I’d run pump 93 and 107 aviation fuel mixed 70% pump 93 and 30% AV Gas.

I think you said it with the LS test... More duration and more LSA to push that peak power out higher for the Ford... Need a different cam in it Richard!

It’s good that you point out none of these engines are stroke limited at 8k. I think the reason short stroke is often associated with higher RPM is with the same top end the short stroke engine simply takes more RPM to move the air and reach peak HP (valve train permitting). It would be interesting to see what happens to that 347 with a shorter stroke even though it's not stroke limited from a piston speed perspective.

That’s go to know. I just bought a CompCam 201-428-17 for a 5.7 based hemi stroker. Cam card says it’s operating range is 2400rpm-7400rpm. But it may see more rpm going through the traps.

The 347 has something jankey in the setup. Dead giveaway is torque and HP take a dip at the same RPM. Love those LS cathedrals, they are a work of art.

For the sbf, is like to see the same lobe profiles but with a wider lsa. That should move the peak farther out if I’m not mistaken.

The problem I ran into revving my ls6 on a track for 20-30 minutes at a time was the timing chain biting the dust. I think a lot of the old conventional wisdom on hydraulic lifters ignores how good the springs and lifters are these days. Of course this frees us up to worry about longevity of Rod bearings and stretch at high RPM. Which the gen 3 and 4 factory lumps still blow away my old 1st Gen SBC's in those regards too. What a fantastic time to run high performance engines.

I run a 347 in Super Street 10.90. I slow the car down for the class, but it is a great little motor that revs, especially, in good air.

Yes! Super exciting test :-) How about doing a big bang engine running to 8K? Less torque required to make huge HP and craaaaazy sound - what is not to like?

id like to see a 4.6 high rpm motor and the 502 ram jet bbc high rpm set up and see what u can get

Jon Kaase was asked about his hugely undersquare IHRA Pro Stock engines and he said that although they didn't look good "on paper", the cars got down the track pretty well. Yes, it is all about valve control.

Would love to see some of these 8000rpm combos done with BTR’s max effort cams with the accompanying short runner intakes.

Having just watched last week’s engine masters, I’d say the tighter LSA (110 vs 118 on the LS) pushes the power down in the rev range and might have limited it up top just a little.

I think the Ford has an issue with valve control. Ha it been a lack of flow or exhaust restriction, I think the curve would just have gone flat. That weird concave curve suggest some kind of harmonic spring issue. Maybe the valve is too heavy or it needs 15-20 lbs more spring rate, because if it had been a collapsed lifter or actual float, it would just drop off in a more convex curve, that's at least my experiences. It is definitely not a shape I associate with flow or runner length tuning issues. Did the springs have dampers?

I feel a roller 351w would of been a better equivalent on Fords end. But that's just my honest opinion. Awesome comparison and work done in this as well though! Great job sir!

I see a modified oil pickup tube , how do you remove welding scale from the inside of the tube . Somehow run a flexible wire brush inside ?

That ford definitely needed some more exhaust header size. It also probably should have had more LSA to help move the power band up too.

Only reason to put a short stroke in a motor is to keep the piston speed down. Bad things start to happen when piston speed gets out of control.

Love the details, but I really want to hear each combo idle and scream!

Would have been interesting to list valve springs used with open and closed pressure.

Back in the 70s I was running a 340 with a crane cam and a hydraulic crane lifters and launched a 8000 RPMs no problems .🏁🏁🏁

Super cool. What spring pressure are you running on each?

I think you may have been seeing the effects of those small exhaust runners. I'd be interested to see if you pick up some numbers way out at the top with 2" primaries. I feel like it's rolling over because it can't get the air out well enough. I love that you keep doing Ford stuff either way. Too many LS the world people. ( I get it, it's the cheapest way to do it, but it's not the only way to do it)

The valvetrain sets the highest rpm where the engine will make power, regardless of bore/stroke... I totally agree. But the reciprocating mass and stroke combination kinda do set the max rpm where it will survive for long periods of time... ;) Today’s lighter pistons let you reach RPMs with stokers where people would have been de-stroking for durability in the 60s-80s, IMO, but even today shorter strokes are easier on parts.

Love your music Richard gets me pumped up in the morning

I think it’s a combination of two things here. First is the intake. It really needs plenum port work and match ported to the heads. Second is that crane cam. I’ve never had any luck with their cams in sbf. Do a hyd flat tappet lifter test!!!!

Changing the rod/stroke ratio is going to make some difference to the overlap interaction between the intake and exhaust flows - good or bad, hard to guess. Fun test, though.

My 347 is pretty standard off the shelf parts. Stock block Forged crank, H beam rods, and flat top pistons 10/2/1 comp. Brodix LH 195 Heads fully cnc Ford racing x cam 542/542 lift Funnel web intake 780 cfm quick fuel carb Made 478 hp at 6200 Made 442 tq at 4200 My guess as to why the sbf made such low numbers is because of mismatched parts. Maybe needed more compression. 🤔 I have no clue, but I would have guessed that screamer being in the mid 650 hp area.

The sine wave is likely the roller cam profile roughness verses the valve sping period. Everything has a natural frequency that gets excitations when at certain engine speeds. If the cam is linished to stop the follower getting agitated, the surge should be eliminated.

Hey Richard I couldn't tell but what bolt pattern was used on the sbf trick flow high ports? There is a small horizontal bolt pattern and the bigger diagonal bolt pattern. I noticed on these heads if you use the small bolt pattern it chops a lot of flow off the exhaust. Trick flow makes a high port specific header flange for the bigger bolt pattern for like $60 if I remember correctly. Also goes to a 5/16 header bolt for more clearence.

The LSA on that Crane came seemed a little narrow. I'm also wondering what the intake centerline was, was it early also? What lifters did you use and what was the seat and open pressure? Are you confident the pushrod length was optimal?

Rich- it may have been said already, but I’m thinking that the longer intake runners on the Ford (in addition of the smaller size headers) may have held it back at the top end a little bit- the LS runners were a lot shorter, and the dual 4 setup may have been able to flow just enough more to keep it revving. There was plenty of cam in the Ford, just thinking the breathing wasn’t there.

Given the drop in power and your knowledge of engine combos, it appears the smaller header created some restriction on the top end. The cam is large enough, and shorter stroke would have revved higher in this case if cubic inches went down with the stroke. A tunnel ram intake on the sbf would have changed things as well. However, one cannot overlook the volumetric efficiency of each combination, favoring stroke length without considering the ratio to rod length, angle of ports and valves, directly comparing valve weights, valve angle grinds, comparing induction manifolds, etc. It is difficult to compare every little variable when there are a couple hundred of them in engine designing... I would have to say that while many combos can be made to turn 8k rpm, a longer stroke with shorter rod will always create efficiency at a lower rpm than the inverse. When you are testing boundaries, though, these factors now become critical; 18k rpm F1 cars being an example. You will struggle to make an small block anything turn 18,000 rpm; the basic design just isn't there. In this particular test, I think sizing the headers and the intake manifold similarly to the LS would have yielded more power at top rpm. Basically 1 7/8" headers with a tunnel ram, maybe more carb...

Short stroke isn’t for RPM potential it’s for longevity of the crank and rods. Dynamic forces at those engine speeds break stuff in the bottom end.

347 all day long. It has lighter pistons. By far. And that makes a huge difference when you start revving up past 7000. Kudos to you also, for using stock lifters to reach out to 8000 rpms. I am surprised by that. I would love to know what lobe profile was used. It surely was easy on the opening and closing ramps to keep the lifters from lofting without using killler spring pressure. They are heavy when they are full of oil.

I can’t say enough good stuff about your channel! Ty for all that you do. Always sharing your info & pushing people tonthe channel. Quick question. M90 supercharger video was great & I had a feeling that it would not improve that combo. What about an M90 on a 4.0 Jeep? Is the 4.0 any good as far as performance? It’s a “cant kill it” engine, but is the output worth the money spent? Future test perhaps?

I'm a Ford guy, the deck is only 8.2". Rod stroke ratio sucks on these strokers. The only reason to run the things is if a 9.5" deck block won't fit, or you're lying bout cubes. Nobody falls for that anymore. Raced them 20 years ago cause I had parts for them. Couldn't afford to step up and build another motor even though could've recycled most of the stuff! We stuck a junkyard Windsor with a used solid lifter flat tappit cam, borrowed rpm heads. Turd was a second faster 1/8 mile!! Ran it 4 years and last I heard it's still running round in a street car. 5.969" conn rod, 3.5" stroke, 9.5" deck! Like to see a cheap build on a 360 Dodge, talk about good rod stroke ratios.

I'm reving my Harley Sportster with a 3.81" stroke 7500 rpm. Cam specs are .600 x .600 lift ,264° x 270° @ .053". Full travel lifters with 1.850 in valves and 1.60 ex valves. Comp cams 7256,spring rate 485lbs/in ,160lbs@1.900" conical valve springs specs im using 185lbs on the seat., titanium retainers. She's still pulling hard when she comes on the rev limiter. Stroke dosent matter it's all in the cam and spring package. Oh yeah a good set of forged pistons are a must have too. Lol That piston speed is moving at that rpm.

do you think the lifters may have pumped up too much at higher rpm and didn't full close the valves. I have heard of earlier hydraulic lifters doing this but crane cams were supposed to be the first manufacturer to fix this problem. I'm talking about early LT1 hydraulic roller lifters pre LS.

How much difference does a balanced rotating assembly make in snap when spinning up to 8000rpm?

rpms always has a price to bear to get there but good bottom end and uper end needs to be well thought therw balance wieght and home work and good parts start there. do the resherch do it right

I think that Crane cam was the limiting factor on the 347. Can you do a video on custom ground rollers versus off the shelf.... Matching cam to head flow numbers since the vehicle info can't be entered? Cam Motion has made almost every build I've done surpass most in not only peak number's but bringing the average up across the board

Hello Richard -I am using solid rollers on a hydraulic roller cam (408 Ford blower motor)

As a question was there anything special you did with the lash on either of these?

Crane's eight thousand rpm hydraulic lifters are awesome.

Should have done a Clevor on the SBF. Maybe the CHI 3V heads. Would be interesting to see oem 4V heads too.

What about light weight rotating mass? Lightweight crankshaft, Knife edged ect. An LS7 has Titanium rods and intake valves, dry sump. would that be a good candidate for High RPM Screamer?

Can you talk about area under the curve vs peak power some time? so many folks think its all about that peak.

I have the 4.8ls with 6.3 rod and stock balanced crank with 3.8 fordged piston......little demon!

I thought the destroke was to make it more reliable at higher rpm. It was a long and short could both spin that fast but the long stroke would wear out rings or cylinder walls faster?

Great video

Rpm is just a number

Hey Richard, what’s the RPM cutoff reason? Is there any lifter wear considerations or do you just stop once the power curve starts trending downward? What sort of engine life are you looking at for LS based motors being revved to 8,000RPM and above? Thanks

What about a 306 vs 331 vs 347 with all other specs same: Intake, cam, compression, etc. Determine value of power gained for vs the cost of increased stroke.

What was the compression ratio on that Ford? Try a dual-plane intake with a high-rise spacer.

Any plans on doing a Dodge/Ram 5.7 Hemi truck/suv engine? I hear they respond well to cam upgrades

yes yes yes it can be done you need GOOD PARTS good specs and know how or boom.get the jb weld out or duct tape that would be good start to.few hp.but rod lenth is also has alot to do with clyder fill you can make it peakee or slow the rpm band on how long the rod is .weight crank pistons .rod lenth has a roll in it.

Hey, have you ever tested a Thumper cam? I want to try one (hydraulic roller) on my Ford 460 but wonder how much power I have to give up in order for it to sound cool.

On this sbf run, which lifters did you use? Were they the crane short travels or others?

Could you use same cams in both engines for a test like that?

same cam on 118 lsa on the Ford might of pushed out past 8k and making power