LS1 with 6.0 heads question

**aquickfive0** · 09-02-2006, 01:56 PM

hi i have a 2002 ws6 trans am with a sts turbo system
im am putting LQ9 heads on it to lower my compession, does any1 know what it will lower to? does it add or loose horse power? will my stock valve covers and rockers fit on there?

please tell all that can help?

**BlwnCamaro** · 09-02-2006, 10:41 PM

Originally Posted by aquickfive0

hi i have a 2002 ws6 trans am with a sts turbo system
im am putting LQ9 heads on it to lower my compession, does any1 know what it will lower to? does it add or loose horse power? will my stock valve covers and rockers fit on there?

please tell all that can help?

The combustion chambers on the lq9 heads are right at 73cc where as the stock ls1 heads are around 67cc I believe. Your compression should drop from 10:1 to about 9.4:1 depending on the thickness of the headgasket you use. A thicker headgasket may yield around 9.2:1, invest in some good headgaskets also. Yes your valve covers and rockers should fit fine. You may lose just a little power with the compression drop but in the bigger picture you will have more power with your turbo cause you could run higher boost levels more safely. Plus the aluminum lq9 heads have similar port configurations as the ls6 corvette heads so consequently they flow pretty decent for stock, and would respond great to a port job also. Also since it will be apart if your budget allows get a good cam that is set up for boost. Generally cams that have good duration, and lift with a tight lob separation work good with boosted applications. However with a stock bottom end having some overlap in the cam will lose some boost and horsepower but will put less cylinder pressure on the stock bottom end. If your on a budget the
ls6 cam with valve springs is pretty cheap and actually works decent with boost, however if your budget allows I would consult comp or other reputable companies that could grind you a custom boost friendly cam or point you in the direction of a good grind that fits your needs and application for the car. You would also need good valve springs, hardened pushrods, ideally good lifters and a ported and shimmed ls6 oil pump or similar. Plus if you are gonna have the engine out I would invest in arp studs and rod bolts for the bottom end. Good luck.

**aquickfive0** · 09-03-2006, 04:43 AM

this is gona be a in car head swap

**GA Country Boy** · 09-07-2006, 04:12 PM

Good advice BlwnCamaro! I think you're right on the money with everything you said. BTW, I've never worked on a 'F' Body...can you do heads and/or cam without pulling the motor?

**cailey37** · 09-08-2006, 05:58 PM

Originally Posted by GA Country Boy

Good advice BlwnCamaro! I think you're right on the money with everything you said. BTW, I've never worked on a 'F' Body...can you do heads and/or cam without pulling the motor?

Yep.....heads and cam can be done without having to pull the motor.......

**SSmoky01** · 09-08-2006, 06:04 PM

Originally Posted by cailey37

Yep.....heads and cam can be done without having to pull the motor.......

I second that.

**GA Country Boy** · 09-08-2006, 06:36 PM

Originally Posted by cailey37

Yep.....heads and cam can be done without having to pull the motor.......

Damn! That's the way it should be!!! I guess I'm so used to Y-bodies where it seems that the drive train gets pulled for just about everything. BUT they can't fool me! When they tell me they have to pull it to change the oil, I just wont let
that happen. I KNOW I'm NOT due for an oil change yet!!!