1/4 Scale merlin project - allowance for honing

[Lloyd W]

A very good day to you all,

The cylinder blocks and crank case now largely completed I am turning my thoughts to the cylinder liners.

These I will make from 4130 seamless steel tube in the annealed state. My first tests seem to show this material to be quite readily machineable.
I know this kind of question chases its own tail, but assuming I can obtain a good shiny smooth turned surface for the bores of my liners, how much allowance on a nominal DIAMETER of 1.35 inch would you consider I should leave for honing.
As I have no real experience in these things I would very much appreciate your advice and comments

Many thanks
Lloyd.

 

[gbritnell]

Honing should do no more than polish the bores. A good surface finish from machining should leave surface imperfections no more than several tenths high so .001-.0015 should be more than enough. If you have to take off .003-.004 to smooth out the surface then your boring isn't very clean.