Looking for advice on how much P2H clearance I should be aiming for. 885 head, Mahle Stroker pistons (IE), M52 crank + steel rods (fresh small end bushings), NA engine, DD, so not going to see 6500+ very often.
Found a few different numbers:
Found a few different numbers:
https://www.hotrod.com/articles/ideal-quench-height/
Quench should be as tight as possible without the piston actually contacting the head. This, in turn, is largely dependent on the type of connecting rods and the engine’s peak rpm. A good rule of thumb is that you can run as little as 0.038 to 0.043 inch with steel connecting rods. Steel-rod street engines that don’t see the far side of 6,000 rpm may even be able to shave this to as close as 0.032 inch. Aluminum rods expand and get longer with heat, so the quench clearance with them should be increased to 0.050–0.065 inch.
Don't spend too much time thinking about quench, get it under .050" & above .035" at the squish band & call it good.
If you are building an engine with steel rods, tight bearings, tight pistons, modest RPM and automatic transmission, a .035" quench is the minimum practical to run without engine damage.
Quench should be as tight as possible without the piston actually contacting the head. This, in turn, is largely dependent on the type of connecting rods and the engine’s peak rpm. A good rule of thumb is that you can run as little as 0.038 to 0.043 inch with steel connecting rods. Steel-rod street engines that don’t see the far side of 6,000 rpm may even be able to shave this to as close as 0.032 inch. Aluminum rods expand and get longer with heat, so the quench clearance with them should be increased to 0.050–0.065 inch.
Don't spend too much time thinking about quench, get it under .050" & above .035" at the squish band & call it good.
If you are building an engine with steel rods, tight bearings, tight pistons, modest RPM and automatic transmission, a .035" quench is the minimum practical to run without engine damage.
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