I have a jdm b18c gsr motor, and I have low compression (120 psi) in the #3 cylinder....I was planning on just upgrading my pistons along with the rings since I have to take them out anyway.

My question is should I get the CTR pistons or the ITR pistons, I want an all motor setup with higher compression. I heard that the CTR pistons have higher compression, but I want to make sure I don't have to any specialty work since I am using different pistons.....Any advice is appreciated.

 

I would go with JDM ITR pistons.

 

CTR pistons will give you a much higher compression, and you won't have to alter them at all to get them to fit.

Just have to decide if you want 11.3:1 or 12.3:1 compression. Beware of 91 octane if you get CTR pistons.

 

Some people were giving me smack cuz I said I wanted all motor and I am a fool for going with a thinner headgasket and higher compression pistons...

With the thinner headgasket and higher compression CTR pistons......I won't have a timing problem, with the crank and the timing of the valves since the gaps will be different?

 

With a thin headgasktet AND CTR pistons, good luck making it streetable, unless you can get high octane pump gas. Also, with a milled GSR head and CTR pistons you can have piston to valve contact, so I don't know if a thin headgasket is such a good idea.

 

Yea, We ran a another compression test after the motor was warmed up...and we got 150 -140 psi this time. Which makes me believe it is something else because the pressure is holding too.

I think I am going to skip the pistons, and JUST replace the headgasket. Any issues with doing this, or any tuning I would need to do ?

Thanks alot.

 

Well yeah when the motor is warm, things expand and seal better, so you're gonna have better compression #'s. That still is low for the motor you have, it should be in the low 200's.