Has anyone used pistons made with offset pins in their Nailhead?
Since custom pistons are the only choice on a performance rebuild, it seems like this would be a great option.
Already spending a grand on custom pistons. It seems like having 4 lefts, and 4 rights, couldn't add too much more to the piston cost.
Forged pistons need more clearance, and offsetting the pins reduces piston slap, and wear, on the rotating assembly by placing the rod angle not parallel with the bore when the piston is at TDC.
Smoother running engine, with less friction. could only add to efficiency and longevity, it seems.....
How much offset to use, and how much, exactly, that calculated offset, will add or take away from the stroke, are formulas I have yet to locate....
It seems I have done all the math for my 401 rebuild. Now, this x factor has me thinking I might integrate this into the equation.......
This is what I have come up with, so far:
Bore - 4.197"
Stroke - 3.69" - crank offset ground to use BBC rods. 2.20" rod journals.
Rod length - 6.8"
Gasket bore - 4.24"
Gasket thickness - 0.016"
Deck height - 10.00"
Top ring down - 0.30"
Head chamber volume - 125cc
Piston dome volume - (-50cc)
Deck to piston - 0.020"
Compression height - 1.335"
CID - 409
Static compression - 10.91:1
Cam - TA25
Dynamic compression - 8.02:1 w/cam installed straight up
Dynamic compression - 8.29:1 w/cam installed advanced 4 degrees.
Agree, disagree, or agree in part?