1.7na

sup guys,

First post on this forum. I posted this question on another forum but didn't get any answers. Hope somebody can give me some feedback.

How thick of a headgasket can you use before cam timing is effected (stock head)? Would it be opposite of a thinner headgasket? 0.012"= 1 degree retard so would every 0.012 on a thicker gasket add 1 degree advance? Thanks for any feedback.

1.7na

Provocateur

A thicker headgasket really cancels out any lower compression you will gain from it because it will allow a larger area for detonation to impinge on and it will make the quench zones of the combustion chamber less effective.

1.7na

Thanks Däs Schmoo. I know it's not the ideal way to lower compression but since I'm in CA, I needed to lower my c/r to be streetable on 91 and also to pass smog (which it did). I had my motor bult in 99 so their was some misinformation back then about the c/r with pct pistons and a b17a motor (negative deck height). If I knew this, I would of ran some p30s or pr3's instead. So you think every 0.012 on a thicker gasket add 1 degree advance? Thanks again for your help.

1.7na

Provocateur

I wouldn't touch the ignition timing unless you have detonation. If you get on a dyno and have some method of tuning the ignition, it wouldn't hurt to smooth out the ignition curves.

1.7na

Thanks again Däs Schmoo. Actually, the reason why I'm trying to adjust my ignition timing is because when i swapped out my headgasket for a thicker one (.54 cometic), I notice that my timing was advance quite a bit and had a hard time getting back to 16. So after doing some research, I changed my cam gears to -2 -2. I can set it to 16 easily now but I just want to make sure the theory of 0.012 on a thicker gasket adds 1 degree advance cam timing. Not trying to advance it for power gains.
I'll have the tuner tune ignition whenever I get a chance to get the car dyno again.

So basically I guess I'm trying to find 0,0 since 0,0 on the cam gears doesn't seem to be accurate anymore with the thicker headgasket. I think -2 -2 on the cam gear is really 0,0 now. Guess this is were a degree wheel would come in handy. Man, getting too old to be playing around with this stuff

Thanks again!
1.7na

Provocateur

Are you sure that the timing belt is seated properly on the cam gears at 0,0? It sounds like it skipped a tooth or something.

1.7na

Yes, I confirmed that the cylinder 1 was TDC (white mark), the gears were - - and the cam holding hole lined up correct with the cam plate (my punch pins went in fine). I also stuck a wood stick to confirm that cylinder 1 was at TDC. That's why I think the thicker headgasket is advancing the cam timing. From what I read, each tooth off is 10 degress timing. My timing is not off by that much. Thanks again for your help.

1.7na

1.7na

Just in case anybody ever does a search for this subject, a thicker headgasket on a stock head should not advance ignition timing very much. I rechecked my cam gears and ignition timing and was able to get stock setting (16*) without much of a problem.

1.7na