mygtr wrote:Just thought i would post my proposed engine combo. Looking for HP estimates from this forum.
Maybe even some improvements.
434 cu in
Scat crank 4" stroke x 4.155 bore
6" rods h beam rods
235 AFR heads
shaft mount rollers 1.65 int 1.55exh
Super Victor (4500)
1050 QFT alky carb
comp cams solid roller 724/668 lift 279/286 dur @ 50 108 lobe sep.
Moroso vac pump.
I am building a LSX same bore and stroke my heads flow 418 cfm and have a 3.28" primary choke size so its for a big revver. Your heads are on the small side probably right for a 383ci or similiar. It will get to a point where it stops making power regardless of your cam, but more won't hurt it can only help. I have seen a similiar combo with a 255cc port volume, unsure of the choke but they flowed 350-360 cfm with 11:1 on pump fuel with 280s cam made 630hp but cranking compression was very low, he went to 13:1 and fitted a tunnel ram which raised the average cross section to move peak torque higher and make the head appear to look bigger lol. He ran two dominators on 102 octane unleaded and it made 797hp. The cross section for the heads were on the smaller side so it loved the extra volume in the runners. They put a lot of work into the single plane but still didnt have the avg cross section of the tunnel ram.
See how it goes your compression and cam is up there maybe the cyl heads need some work, with the engine being on the larger side it will respond a lot to cyl head, manifold, pipes.
7Al 3 msd ignition.