An example adding to perspective.

A 454 with Peanut Port heads (70s-80s) that are mildly ported out, will make 570HP at around 5600rpm with 2.19 valves. Reliably.

With low...just over 8:1 CR...and a FT hyd cam.

Popular Hotrodding Mag in 2001..had an article on a 350 SBC ZZ4 Short Block...with 195cc AFR Heads. All off the sheld parts build. Made 520HP at 6600rpm.

PP heads have about a 208CC port...avg 13more CCs than the SBC port...but the BBC port longer...and it really comes down to port CSA. It's a high velocity port when drawn with 454 cubes and some rpm....but they can flow a lot of air.

Well I’d certainly expect it to do better than a peanut port 454 with low compression, even with the same size valve. So maybe the potential is higher. I was just using a CFM rule of thumb, but huge cubes and enough cam could beat the estimate.

I mentioned the PP head 454 specifically because it's a well setup marine engine for no more than 5800rpm. One of the reasons to use a 2.19 int in a PP head...is to fix the GM bore job into the valve throat..destroying any potential to do a proper valve job.

The PSI engines are def an interesting project.

Ported PSI:
[email protected]
[email protected]
Def going to have some potential.