Double Jug Gasket???

Discussion in 'Performance Mods' started by SuperDave, Feb 15, 2013.

  1. SuperDave

    SuperDave New Member

    My Chinagirl came with 2 gaskets between the jug & case. I've read sometimes that happens at the factory, as mine did. If I remove 1 of 'em, what's that gonna do to the performance? Will it move the powerband? I KNOW this will affect timing, lowering the ports & increasing compression.
    Will it hurt?
    Will it help?

    Has anyone done this & what happened?

  2. Fabian

    Fabian Well-Known Member

    It's not even an issue. I run a double base gasket on my engine to lift the cylinder slightly, which gives more open time for the transfer ports , as their open time window is restricted from the factory. The double base gasket also opens the exhaust port slightly earlier which in theory should raise the power band, but in reality it doesn't because the greater restriction is in the standard muffler.

    The next time the cylinder is replaced, i'm going to try 4 base gaskets, combined with an ultra thin copper cylinder head gasket to restore the compression ratio.
    When i rebuilt my engine and dummied up the cylinder with 4 base gaskets, the transfer port open window looked much more healthy, and so did the exhaust port which was never fully open at bottom dead centre with a single base gasket installed.