[tpepmeie]

All this talk about 8K is entertaining, but nobody has mentioned the cam chains. If I recall, they were the failure point for the World Challenge cars, when they were sustaining 7500 for extended periods. JVD could chime in here, I'm sure.

Maybe stronger chains are available these days?

The other limiting factor to making power that high (8000+), is the port cross-section. Especially as you increase the stroke. As the piston speed goes up, the port choke rpm is reduced. The best you're going to get at the intake throat is about 38mm, or 1.5" diameter just under the valve seat. I think Rod has gone to 39, but with very thin port walls.

Finally, not least, the intake tuned length (about 13" total) is perfect for 7000 rpm. That is where the wave tuning is strongest. This can be fudged a little higher, with the big plenum runners, and creating a taper, to reduce the effective length of the port.

Best I've heard is a Jeal/Kirchhofer 415 which went 724 hp at the crank, at 7550 rpm. Impressive as that was, the BMEP (hp per cid, per k rpm) was lower than the best 385/415s from LPE, etc. That suggests to me that pumping losses and friction was significantly impacting power at that high RPM.

Todd