Piston to Head Clearance advice. ????

[lewtot184]

depends on the angle in relationship to the piston travel that the measurement is taken. i used 45 degrees as an example. i think your measurement is taken at less than that angle which means more vertical clearance. the theory doesn't add or subtract angle, you the measurer do.

 

[moper]

depends on the angle in relationship to the piston travel that the measurement is taken. i think your measurement is taken at less than that angle which means more vertical clearance. the theory doesn't add or subtract angle, you the measurer do.

x2.

Piston to head clearance in a hemi, any manifacturer's hemi, has little to compare to a wedge or canted wedge design's piston to head clearance because the surfaces are brought in proximity to each other on an angle. At running temperature pistons do not move fore or aft in any appreciable amount along the pin axis. The skirt clearance does allow for rock at BDC and TDC but we're talking about amounts less than .020" on most engines. As an example in a 4.25 or 4.28 bore with a reasonably long piston (a Mopar 426" Hemi) the rock at TDC (measured at room temperatue) should be less than .015".

 

[dvw]

It's very easy. You answered your own question. They haven't appeared to hit, then they didn't hit. Run it.
Doug