Thread: Cheap build whatcha think?

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With a 350, you want to pay attention to the compression height (measurement from the centerline of the wrist pin to the top of the piston crown) of the piston. Stock is 1.560". Rebuilder piston are often shorter and will increase the squish/quench clearance between the squish pads on the piston crown and on the underside of the cylinder head.

When the piston comes to top dead center, it comes very close to the underside of the head and us builders shoot for a squish/quench (a clearance) of 0.035" to 0.045" between the piston and the head to prevent detonation on pump gas. You can jockey the piston compression height, piston deck height (measurement from the piston crown to the deck of the block with the piston at top dead center) and the head gasket thickness to arrive at a proper squish/quench. With squish/quench being the correct measurement of 0.035" to 0.045", when the piston approaches top dead center, the fuel/air mixture is squeezed out from the area above the piston (below the head) and is jetted across the combustion chamber at a very high rate of speed, which breaks up rich pockets of mixture and makes the entire slug of mixture burn more completely, making more horsepower and eliminating detonation. You can see the same effect of squish/quench by dropping a book flatly onto a table top.
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