Post by
amc49 »
https://forums.nicoclub.com/amc49-u275146.html
Thu Jul 25, 2019 6:55 pm
Using a gasket only .004" one way or the other in thickness will not really change anything. And if your shim is only that, or .1 mm. you are really silly as that can blow out easy as spit. A shim that thin then in essence becomes like greasing the head gasket, it stops one side of the thick gasket from biting into the head or block to move around in use. If the gasket is a graphite one you likely failed it using a shim.
You absolutely cannot crush a gasket in a local area (vise) and expect it to be the same crushed thickness as one crushed all over, the unit measure of crush goes up with limited area as it is easier to crush limited area as vs. a much bigger area, the bigger area will not be as thin when done.
On FelPro gaskets..................I used them for many years and up to 13/1 compression ratios on all kinds of racing engines. The parts may have changed some obviously with the world moving to cheaper product. I went to the veggie website video and beyond the thin firering I think the guy is crazy. You do NOT want the firering tight with gasket unused, that gets crushed harder due to not being tight and if you want to stupidly monkey around with the firerings before using the gasket then good luck with that. The fire rings ARE loose before you tighten the gasket up, the torque is what sets them hard in place. That is NOT a mark of a bad gasket, only a bad mech. You need to look for gasket overhang if overboring to make sure the gasket does not protrude into the chamber and if it does then that is mech incompetence at not checking for it. I CAN say we failed Victor gaskets repeatedly back then to never use them again and they will have cheapened out processes as well so beware.