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Discussion Starter #1
too lazy to go look up piston heights and try to figure things out on my own, so ill just ask here. I know they use the 302 piston in a 351w for the 393 stroker kit, but can you use a 302 piston in a stock stroke 351w and approx what will the compression be with a flattop 302 piston and 60cc head?
 

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Just by reasoning that without the stroker crank the stock rods and 302 pistons would never even come close to the top of the cylinder. They would end up in the hole .4-.5 of an inch. I guess you could use a long rod kit and make it work.
I hope that was right
 

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According to my manual the distance from the centre of the wrist pin to the top of the piston is .136 shorter on a 302 piston than on a 351.These are stock piston figures.
 

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Discussion Starter #4
so is that a bad thing? will it affect anything else besides compression ratio? what do you think compression will be
 

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Looks like somewhere around 8 to 1. But you quench would be ****.

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<font size=-1>[ This Message was edited by: dragman64 on 3/13/02 3:20am ]</font>
 

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Having a piston down the hole eliminates quench. The quench area is the flat part of the piston that would contact a similar flat area on the cylinder head if you had .000" assembled quench height. In a running engine, the .040" quench decreases to a close collision between the piston and cylinder head. The shock wave from the close collision drives air at high velocity through the combustion chamber. This movement tends to cool hot spots, averages the chamber temperature, reduces detonation and increases power.
Since it is the close collision between the piston and the cylinder head that reduces the prospect of detonation, never add a shim or head gasket (or set the engine up with the piston way down in the hole) to lower compression on a quench head engine. If you have 10:1 with a proper quench and then add an extra .040" gasket to give 9.5:1 and .080" quench, you will create more ping at 9.5:1 than you had at 10:1. The suitable way to lower the compression is to use a dish piston. Dish (reverse combustion chamber) pistons are designed for maximum quench area. Having part of the combustion chamber in the piston improves the shape of the chamber and flame travel.
 
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