Not to hijack this thread, but here is one more unlimited racer designed by Skip Holm and AirBoss (my company). This was done just before the weight limitation was brought into effect. So, it never came to be. It would left all the boys in the wake - lol - after all the sqawks were worked out. We should probably start a new thread if racer discussion are to continue.
How was this supposed to be powered ?
The racer was going to be powered by a custom build V-12 that would put out over 2,750hp under race conditions. The aircraft would have been very light for a racer - in the neighborhood of 4,200lb gross.
Falconer/LS based?
1000 cu in ?
Considering that there are 400 cubic inch LS V8s without overbore, that'd put a V12 to 600ci before you start enlarging things. Add lots of stroke for more displacement till you need to notch the pistons to clear the counterweights, then add bore. That'd be 527ci V8s, 790 cubic inch V12s, maybe 800ci with a squidge more overbore.
572ci versions of the V12 LS are pushing 1000hp in mild tune, so an 800ci should be around 1400hp in mild tune. Add lots more boost, water injection, and spray bars on the radiators to help pull more heat out, there you go.
Though the Falconer may have been built on the old 454 big block architecture originally, which can get stupid big in drag engines. 872 cubic inches is the biggest I've seen as a V8. That'd be 1300 cubic inches as a V12.