RE: Q40 Piston height
Are we talking Nelson short stroke or long stroke here?
Here are my setup numbers for my long strokes. Keep in mind I am in Calgary at 3300 feet ASL.
Individual results may vary. You will need to play with the setup +/- .002" or so.
Sleeve height = 0.192" at TDC
Head clearance = 0.019" to 0.022" @ TDC (depends on glow plug longevity, piping characteristics)
For short stroke, it's been a long time but if memory serves me it might be something like:
Sleeve = 0.196" and Head = 0.013" - 0.015"
It takes a bit of playing around but if you have no where to begin, start with these numbers.
Randy Smith