Raced Guy

I was told if you swap LQ9 heads onto an ls1 you will lower the compression by about 1 point, is this true. And if it is, is everything as far as the valvetrain and what not the same ???

orangeapeel

iTrader: (18)

Valvetrain is the same. It may drop it one point, but depends on gaskets as well.

Raced Guy

Well basically im looking for a way to lower compression some because im going turbo and dont want to tear into the bottom end right now. Just want to lower it a little for saftey sakes. So can i just change out the head gasket to lower compression, i know you can to raise it.

orangeapeel

iTrader: (18)

yeah it works both ways...I am not an expert on which gaskets will +/- compression. I just know that is how some people move it around. But yeah, when you said that you were going with the LQ9 heads i knew you were looking to drop your CR.

Raced Guy

Yeah then i will fell alot safer about running the boost i want to run.

orangeapeel

iTrader: (18)

What ideal CR are you looking for? 9.1, 8.5?

Raced Guy

If i can get it in the low 9's i would be happy, id be very happy with 8.8-8.9 to 1.

orangeapeel

iTrader: (18)

yeah that would be ideal I would think for some major forced induction.

Raced Guy

.....

Raced Guy

So can anyone verify if these heads will lower compression???

JZ'sTA

iTrader: (23)

Compression with a typical LS1 bottomend and a .054 gasket with non milled LQ9's will be right around 9.5:1