“…Runout concentricity to cylinder bore realy is not critical, but removing a slight amount of metal to get the fit to the cooling jacket just right is important.
Here is what I would do: …”

pe reivers

Exactly. English is my primary language, I could not have said it as well!

I found that by trying not to cut the mandrel length (to save the stock for another use) That the runout was being exaggerated... I cut it in half, and will split the end next to the drive dog for a small wedge to hold the cylinder snug,but not heavily forced to the mandrel.

I read up on the theory of external lapps and made one. I made it .001" undersize before splitting and segmenting.
I gave it a test on the part,but I probably should take care of most of the.0025 taper first.
The little can in the picture holds two grits of lapping compound.


Buck: Whatcha building there?