FWIW I'm running a 440" twin turbo engine in my 71 TA. 67' 400 block with splayed mains. Deburred and prepped. RPM 4" forged crank. 6.635 BBC spec H-beam Eagle rods. Icon dished pistons. Comp Cams solid flat tappet, .508 lift cam with #96 heads that are mildly ported. Cheap($184 each) Ebay GT45 turbos on home built long manifolds. Blow thru C&S carb on e85. Been street raced for over 2 years, shifting at 6000 rpm or so. Car weighs 3650 with me in it and has been 9.16@153 at 7600' corrected elevation. I believe that short stroke and relatively low rpm is what's keeps it together. I don't see any reason that a 4.5" crank won't work if the rpm is kept down. May not be ideal but will work. Good luck with it!
|