Thicker base gaskets ?

[maskmanLS6]

Alright guys im asking for a flaming but i gotta ask anyway. My question is about Base gasket thickness, and port timing. I think my cylinders were decked at some point because when at TDC my pistons are coming out about .010 or just enough for a thumbnail to catch on the outside rim of them if you try to scrape your thumbnail across the top of the cylinder onto the piston. My compression with a stock unshaved head and stock gasket is 140psi. Im thinkin that a thicker base gasket will cure this but im worried about it messing with my port timing, Any advice would be appriciated .

[lms1977]

do a squish test if it comes out fine .040-.05 I would just use it as is.

 

if you change the base gasket thickness you will change the port timings... I think .01 is around 1 deg port timing but I might be off on that number

[maskmanLS6]

do a squish test if it comes out fine .040-.05 I would just use it as is.

 

if you change the base gasket thickness you will change the port timings... I think .01 is around 1 deg port timing but I might be off on that number

 

Thats what im planning to do, i dont think the .010 height on the TDC is gonna hurt anything but wanted some opinions before i made any changes.

[RadarRacing]

There are a bunch of motor options . Is your motor a 4 mil stock cyl? What thickness is the base gasket? Any spacer plate? There are different rod lengths, different pistons for stock strokes as well as longer stroke motors. Its pretty easy to use a feeler gauge and get the pop out measurement and the same for the step in the head. If it is a stock cyl unported it is very common to have the wrong base gasket when someone does a rebuild.

[Burt Reynolds]

If you find your running stock everything,and the cylinders just have been slightly decked,and your squish is to tight,you wont have a problem running a thicker base gasket,it will change your port timing a little,but not to where its going to be a big deal

[maskmanLS6]

There are a bunch of motor options . Is your motor a 4 mil stock cyl? What thickness is the base gasket? Any spacer plate? There are different rod lengths, different pistons for stock strokes as well as longer stroke motors. Its pretty easy to use a feeler gauge and get the pop out measurement and the same for the step in the head. If it is a stock cyl unported it is very common to have the wrong base gasket when someone does a rebuild.

 

My cylinders are stock with a port job, and my crank is a stock stroke vitos crank. No spacers or special gaskets, I didnt think to gauge the base gaskets when i put them down because i assumed they were all the same in a stock gasket set. My squish is ok now but its tighter than normal for stock head and gasket. I have 140psi compression with all stock gaskets and head. And with the port work i have it should be a little lower than stock i would think. It runs great like it is and is all i wanted it to be. The only concern i have is if its gonna cause head gasket problems but i think its gonna be fine.

[maskmanLS6]

If you find your running stock everything,and the cylinders just have been slightly decked,and your squish is to tight,you wont have a problem running a thicker base gasket,it will change your port timing a little,but not to where its going to be a big deal

 

My squish is ok just tighter than it would normally be with stock head and gaskets, I was worried about it causing head gasket issues but its doing fine. My compression is a little high for stock demensions but not too high for pump gas. Its at 140psi with port work and stock stroke and head but thats the only side effect it has.

[maskmanLS6]

I really appreciate all the advice and info from all you banshee pros,,I wish i would have joined before i started building this bike. There is a wealth of info and advice here.