b00stedbyFastrax

in a perfect timed engine with cam gears, pointing a timing light at the gear marks should show them in sync with each other, Right? Now if one were to put a thicker head gasket to drop compression, this would put the cams out of sync with each other (ie intake cam would be advanced) . Is it possible to use the timing light to degree the cams so that they would be in sync instead of a degree wheel? What do you guys think?

earl

How do you define perfectly timed? 0 degrees advanced? Wouldn't use lose that perfect timing when you replaced the head gasket? Not sure what you are getting at. Why not just use your cam gear degree markers to correct?

b00stedbyFastrax

what i am getting at is that if you take a completely stock engine and put in some adjustable cam gears , start up the motor and point a timing light at both gears, the timing marks on the gears should line up with each other (similar as the crank pulley red mark would be lined up with the pointer on the cover). now if you were to install a thicker hg, the cams would be off depending on the thickness of th HG. so to get back the cams to their original setting, could the timing light be used to set the cam gears (adv/retard) so that they line up with each other?

Jared

wont work, your timing light is going to be firing at whatever your advance is, not tdc where the cam gears would line up. If you do have a light that can calculate advance, and set it to whatever your advance is, then sure, your cam gears should line up, unless you've changed something. milling head/block or going witha thinner hgasket advances cam timing, thicker hgasket retards cam timing.

earl

Hey Jared, is there a rule of thumb as to how many thousandths it takes to affect cam timing by one degree?

b18bturbo

Earl,

Most blocks/heads are also being decked and usually .0005 or more are usually removed and milled away. But dont we also want to preserve the quench area in the cylinder The area wiht thicker head gasket would increase the quench area for combustion Dont you want the quench area to be sufficient to cool the hot spots and reduce the detonation. I have been told .040 quench area is the way to go.

From what i have seen and built the .046 gasket compared to .076 gasket the the timing goes off approx 2-4 degrees. I would assume that a 2mm gasket would throw timing off about 4 degrees.

What do you think?


[Modified by b18bturbo, 9:47 PM 12/1/2002]

earl

I'm not sure, Viren but we kind of do what you are saying. Our #1 motor has been decked .020 because of an o-ring problem. We have to use pistons with a custom pin height so as to not stick them out the top of the block. We then use a thicker gasket to bring the head back to stock height. This way timing is not affected but, of course, the compression ratio is lowered slightly.

b18bturbo

thats excactly what we do we deck the surface to make sure it true then we use a .046 or .076 depending on the deck height we took off the head and block. Its goo make sure you do that to keep the surface true just my opinion.