Thread: Decked?

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Before you deck the block, you want to find out what your options are for head gasket thicknesses, then you can determine how much to deck it to reach your target of 0.035" to 0.045" squish figure. I was just using these 2 thicknesses as examples. You may have a choice of 3, 4 or 5 different thicknesses from which to choose, so then it's up to you to do the math and determine how much you will deck the block based on the gasket you have chosen.

Zero deck means that you still have the thickness of the head gasket between the piston crown and the head.

If you have a large bore motor where there may be more piston rock in the bore, or if you're using forged pistons with a considerable piston to bore clearance, you might want to use a squish of closer to 0.045". If you have a small bore motor or are using cast or hypereutectic pistons with a tight piston to bore clearance, you might get away with tightening the squish up to 0.035". I've talked to some engine builders who run tighter than that, but I won't recommend it on this board.