Cylinder Head Surface Finish?
Cylinder Head Surface Finish? What is the proper finish of the Aluminum cylinder head surface? The Patriot Performance LQ9 heads that I bought and put on my L92 short block have a real smooth finish, almost mirror like? I always thought that they should have a little rougher finish to seal properly, but I put them on as they were
The reason I am asking is my tuner says that I may be losing compression when my engine gets hot. I have the new FelPro head gaskets and the car runs decent, but it does not make good wot power. After I put the FAST 90/90 combo on, the car lost power. It went from 450 rwhp/470rwt to 420/440. The power really drops after 5,000 rpm. I am going to pull the heads and have them resurfaced. I am also going to change the cam to one that Patrick G recommended, but right now I am frustrated!
Anyone else ever have a similar problem?
The reason I am asking is my tuner says that I may be losing compression when my engine gets hot. I have the new FelPro head gaskets and the car runs decent, but it does not make good wot power. After I put the FAST 90/90 combo on, the car lost power. It went from 450 rwhp/470rwt to 420/440. The power really drops after 5,000 rpm. I am going to pull the heads and have them resurfaced. I am also going to change the cam to one that Patrick G recommended, but right now I am frustrated!
Anyone else ever have a similar problem?
I just found an answer here: http://www.aa1car.com/library/ar996.htm
I guess I won't know unless I pull the heads and check them?
I guess I won't know unless I pull the heads and check them?
What is the proper finish of the Aluminum cylinder head surface? The Patriot Performance LQ9 heads that I bought and put on my L92 short block have a real smooth finish, almost mirror like? I always thought that they should have a little rougher finish to seal properly, but I put them on as they were
The reason I am asking is my tuner says that I may be losing compression when my engine gets hot. I have the new FelPro head gaskets and the car runs decent, but it does not make good wot power. After I put the FAST 90/90 combo on, the car lost power. It went from 450 rwhp/470rwt to 420/440. The power really drops after 5,000 rpm. I am going to pull the heads and have them resurfaced. I am also going to change the cam to one that Patrick G recommended, but right now I am frustrated!
Anyone else ever have a similar problem?
The reason I am asking is my tuner says that I may be losing compression when my engine gets hot. I have the new FelPro head gaskets and the car runs decent, but it does not make good wot power. After I put the FAST 90/90 combo on, the car lost power. It went from 450 rwhp/470rwt to 420/440. The power really drops after 5,000 rpm. I am going to pull the heads and have them resurfaced. I am also going to change the cam to one that Patrick G recommended, but right now I am frustrated!
Anyone else ever have a similar problem?
With the LQ9 heads, whats your compression ratio at? What size chambers did ya get?
compression should be 10.8 to 1. 72cc Combustion Chambers, 0 Piston Deck Height. .053" thick 4.1" bore head gaskets. This engine should be making close to 500 rwhp. I think the cam is hurting it now, but I am not going back. The FAST 90/90 stays. Besides, I don't have anyhing to go back too. Sold my old stuff to help pay for the new.
Last edited by Deeavi; Nov 1, 2007 at 01:56 PM. Reason: add stuff
