Rotary Car Club - View Single Post - Semi-PP thought/question

NoDOHC · 05-03-2009, 07:27 AM

When I considered this, the biggest issue was how to close the primary ports when not in use. Because the primary ports close well after the compression stroke has started, they will destroy most of the benefit of the peri-port. I have considered devconing all the ports shut except for the secondaries (5th and 6th port only) and using them for idle and the peri-ports above 4,000 rpm or so.

I have no doubt that this can be done, I just haven't found a good way to make it work well.

05-03-2009, 07:27 AM	#5
NoDOHC The quest for more torque Join Date: Sep 2008 Location: Sheboygan, Wisconsin Posts: 855 Rep Power: 18	When I considered this, the biggest issue was how to close the primary ports when not in use. Because the primary ports close well after the compression stroke has started, they will destroy most of the benefit of the peri-port. I have considered devconing all the ports shut except for the secondaries (5th and 6th port only) and using them for idle and the peri-ports above 4,000 rpm or so. I have no doubt that this can be done, I just haven't found a good way to make it work well. __________________ 1986 GXL ('87 4-port NA - Haltech E8, LS2 Coils. Defined Autoworks Headers, Dual 2.5" Exhaust (Dual Superflow, dBX mufflers) 1991 Coupe (KYB AGX Shocks, Eibach lowering springs, RB exhaust, Stock and Automatic)