This is a conceptual question more than anything, and based upon what I've been reading about the new BMW M3 and M5.

So, how do you get a V-8 to rev up to 8,000+ RPM? Is this a stroke-length limitation, is this a valvespring/retainer limitation issue, both, or more? Would it be possible to do it with our motors?

I have to say, the prospect of getting a V-8 to 8,000 RPM both scares and excites me at the same time. :hmmm: :eek2: :drive:

go try it and get back to us :jest:


yikes :eek2:

8k little high, with the right cam and intake 7k is doable pretty easy.

Stress on the components is exponential, not linear, with velocity.

There is a reason F1 V8s only have a stroke of 28mm, as opposed to the ~4 inches (102mm) of our V8s.

Stress on the components is exponential, not linear, with velocity.

There is a reason F1 V8s only have a stroke of 28mm, as opposed to the ~4 inches (102mm) of our V8s.

Hence my question. :D

So I guess smaller mass (smaller components and lighter weight) coupled with lower velocity (shorter stroke) are the main variables contributing to rev-ability?

Taking this info into account, since the 4.8L has the shortest stroke (3.268) out of all the LS1-based engines, would this be the crank to use if you wanted to rev it up?

I just realized that at the end of the day, the engine still has to mate up with a transmission, and the 4L60E/4L80E/6L80E are likely not up to the task of accepting 7500 RPM+ input....or are they? :confused:

Hence my question. :D

So I guess smaller mass (smaller components and lighter weight) coupled with lower velocity (shorter stroke) are the main variables contributing to rev-ability?

Taking this info into account, since the 4.8L has the shortest stroke (3.268) out of all the LS1-based engines, would this be the crank to use if you wanted to rev it up?

I just realized that at the end of the day, the engine still has to mate up with a transmission, and the 4L60E/4L80E/6L80E are likely not up to the task of accepting 7500 RPM+ input....or are they? :confused:


4.8's are known to love higher rpm; Hell Quik revs his turbo stock bottom end 4.8 to 7000+ on a regular basis. I'd like to see a block with LS1 pistons and a 4.8 crank or even a 6.0 block with one to see what it'd do; low end would be non-existent but it'd scream up top.

I'm also under the impression that its rpm that kills a lot of 4L60's; might not always be the case but I think it has a lot to do with it.

I'm also under the impression that its rpm that kills a lot of 4L60's; might not always be the case but I think it has a lot to do with it.

Yeah, that's what crushed my joy - realizing that even if I could get an LS1-based motor to rev to 7500-8000, I'd still be left with how to apply the power to the ground.

Anyone know what the practical (vs. theoretical or spec'd) limits are on the 4L60/4L80 trannies?

The m5 has a 305ci V10 and the M3 has a 4l V8. The smaller engine with a smaller stroke is what is allowing them to achieve 8000rpm limits.
The larger your stroke the more mass your moving and the less stable things will be at high rpms.

For instance the Ariel Atom3 comes with a 2.4L V8 pushing 500bhp and revs to 10,000rpm.

thats just like a little skinny guy being able to run faster than a big heavy tall guy

The m5 has a 305ci V10 and the M3 has a 4l V8. The smaller engine with a smaller stroke is what is allowing them to achieve 8000rpm limits.
The larger your stroke the more mass your moving and the less stable things will be at high rpms.

For instance the Ariel Atom3 comes with a 2.4L V8 pushing 500bhp and revs to 10,000rpm.

There's also a trade-off in the TQ department when you build a motor to rev high. I think the M5 is ~500HP/400TQ while the M3 is ~400HP/300TQ.

There's also a trade-off in the TQ department when you build a motor to rev high. I think the M5 is ~500HP/400TQ while the M3 is ~400HP/300TQ.

the m5 has a little over 500 hp and 383tq , thats a big split

horsepower just tells you where the torque is made. If its split big like that, its well above 5252 rpm (the point where hp and tq cross).

go try it and get back to us :jest:
yikes :eek2:

What he said.

...So I guess smaller mass (smaller components and lighter weight) coupled with lower velocity (shorter stroke) are the main variables contributing to rev-ability?

Taking this info into account, since the 4.8L has the shortest stroke (3.268) out of all the LS1-based engines, would this be the crank to use if you wanted to rev it up?


Sandog, light weight components in valvetrain/ recip. mass help, but so do multi-valves. They rev to the moon.
I member HotRod built a 302 LT-1 & it was a "revver". Short-stroke. Just like the 302 back in '69.
Like StrokerAce03 said, his impression is rpms kill a lot of 4L60's or has a lot to do w/. their demise, our heavy trucks don't help things.

The m5 has a 305ci V10 and the M3 has a 4l V8. The smaller engine with a smaller stroke is what is allowing them to achieve 8000rpm limits.
The larger your stroke the more mass your moving and the less stable things will be at high rpms.

For instance the Ariel Atom3 comes with a 2.4L V8 pushing 500bhp and revs to 10,000rpm.

Ariel Atom is a lil beast according to your specs. :eek2:

I usu. just look @ HP/ TQ & ETs. And @ what point their making those #'s. I know the older Ferrari, I forgot if it was Testarossa or what not had a V12 5.0L. I thought wow that's kinda small displacement. But many foreign nameplates use multivalves & rev up, where U.S. uses pushrods & cubes.

FWIW, the successsor to the Ferrari F430, I believe it's a F458 makes 580 HP, redline @ 9000 R's. Lemme go find spec, I just read last night.

People rev big blocks to 10K+ rpm, you should be able to figure something out. :D

The owner of our shop has a 632 bbc in his boss hoss, its built to the moon, but the builder told him to set the rev limiter at 8100, but the power really falls off around 75-7600 from what i can feel.

The owner of our shop has a 632 bbc in his boss hoss, ...

That's crazy on a bike!!!:loco:

The Ferrari 458 Italia I mentioned earlier, 570 HP 4.5L (+80 over the F430) is cleaner, greener, & more fuel efficient than the smaller/weaker 430 engine - Go Figure, in a Ferrari!
Redline:9,000 Rpm, the highest winding engine ever in a non-racing Ferrari. Tho, IMO, they're a thinly disguised racecar anyway.

0-60 3.3 sec for ~$200k.
I'll take 1 please. :hail:

4 years ago we were turning a 7L LSx well over 8k RPM at SAM. Of course it had very good cylinder heads and a very good solid roller valvetrain.

I've revved my to 8k on accident, usually shift at 7400 tho.

my brother has a SBC 355ci in his mud truck.. 2bolt mains, stock rods, Probe lightweight forged alum pistons, worked camel hump heads and he holds it at 7000+rpms all day long at the mud bogs. Ignition cant keep up above 7500 :(

Its lasted for years like this. Pulled it apart and put new bearings, cam, lifters, pushrods, springs and ported the heads, new intake and carb. Its unkillable as far, and he is known to break anything he gets his hands on.

4.8's are known to love higher rpm; Hell Quik revs his turbo stock bottom end 4.8 to 7000+ on a regular basis. I'd like to see a block with LS1 pistons and a 4.8 crank or even a 6.0 block with one to see what it'd do; low end would be non-existent but it'd scream up top.

I'm also under the impression that its rpm that kills a lot of 4L60's; might not always be the case but I think it has a lot to do with it.

Quik shifts at 7500 when he runs the quarter, IIRC. That's damn high for only having rod bolts and a double roller timing chain. I'm sure he could push it to 8k a couple times if he wanted to.:D

i bought a cheap ass regrind cam from a guy and wen tuning for it im shiftin at 7k with my lil 4.8 and sounds pretty down loud wined up sh it load of topend for me i think

what you were talking about with the 4.8 crank in a 6.0 block is pretty much the same thing as destroking a sbc 400 to a 377. a guy at work has a 377 in his dirt track car, it runs at 9000 rpm all night long. they make good power but their main advantage is being quicker revving over other stroker motors, you just need to buy good parts becuase with the higher rpm comes more wear and tear.

I have a built 377 in my 67 Camaro. They're badass engines :headbang: It hasn't been in very long, so i'm still doing some tuning and tweaking before i start winding her up.

the setup for HP with high rpms is big bore and short stroke. take a lq4/9 block bore it .030 over if necessary, drop in the 4.8 crank if you can get the rods and pistons to make it work. (i believe when this was seriously looked into awhile back, that you couldnt get rods that would work?) you would then have a 7500rpm ++ capable motor and actually be able to make some power with it.

would be perfect with a t56 and a lightweight flywheel :devil:

why does everybody ALWAYS want to destroke an engine when there is talk about high RPM?

because long stroke, high-rpm engines have alot of piston velocity and that wears things out VERY quickly and most of the time you dont want to have to rebuild your street engine every oil change.

Not really a help for the OP, but I do know of an LSX being built that will be shooting for 1000 fwhp N/A while spinning somewhere in the 10000 rpm range... Yes, the dood is a nut, but he's very good :)

Not really a help for the OP, but I do know of an LSX being built that will be shooting for 1000 fwhp N/A while spinning somewhere in the 10000 rpm range... Yes, the dood is a nut, but he's very good :)

Link? Email address? I'd like to talk with him.

because long stroke, high-rpm engines have alot of piston velocity and that wears things out VERY quickly and most of the time you dont want to have to rebuild your street engine every oil change.
Did you read my first post in this thread? ;)

big bore short stroke, lightweight rotating assembly, good heads, good intake, big cam, shaft mount rockers, lightweight valve train..8000+ no problem.. +1 on 377 motors quick high revvin motors

go over to hardcorels1.com and ask this exact question.... there are a few guys there that have set up stock..... yes I said stock 6.0L short blocks that spin 8K in rails and they haul ass.

4 years ago we were turning a 7L LSx well over 8k RPM at SAM. Of course it had very good cylinder heads and a very good solid roller valvetrain.

How long did it last and was it driven daily?