Pocket porting - ZR-1 Net Registry Forums

cvette98pacecar · 08-02-2011

Does anyone have any flow charts on stock heads vs. fully pocket ported heads?
Before I invest the money to buy heads, blueprint them and fully pocket port. I would like to know what the increased flow rates are. Of course I know that the intake, throttle body will also need to be done as well.

Marc Haibeck · 08-03-2011

Pocket porting will not accomplish much on the LT5. The ports are beautifully shaped in the area from the valve seat and back an inch or so. Porting in that area is probably good for only about five hp. The porting gold mine on the LT5 is the intake port volume. Going from the OE 33 mm diameter to 36 mm from the valve guide to the plenum will add 60 hp or more on a 90 ? 92 350 ci engine.

08-02-2011	#1
cvette98pacecar Join Date: May 2011 Location: Sydney, Australia Posts: 2,479	Pocket porting Does anyone have any flow charts on stock heads vs. fully pocket ported heads? Before I invest the money to buy heads, blueprint them and fully pocket port. I would like to know what the increased flow rates are. Of course I know that the intake, throttle body will also need to be done as well.

08-03-2011	#2
Marc Haibeck Join Date: May 2007 Location: Addison IL Posts: 250	Re: Pocket porting Pocket porting will not accomplish much on the LT5. The ports are beautifully shaped in the area from the valve seat and back an inch or so. Porting in that area is probably good for only about five hp. The porting gold mine on the LT5 is the intake port volume. Going from the OE 33 mm diameter to 36 mm from the valve guide to the plenum will add 60 hp or more on a 90 ? 92 350 ci engine.