cylinder boring

[waynekreitzmann]

My biggest deal is how much do you leave to hone half a thou or cut it to size??

[barnett468]

Also what about honing?

My biggest deal is how much do you leave to hone half a thou

You would leave half a thou.

or cut it to size??

What?

[cbx1170]

I have done a lot of surface finish measuring testing and documenting for engineers. sorry half a thou is, even depending on sharpness and shape of your bit and competency of person setting up and doing the machining... not enuff, boring or lathing an (iron) cylinder is actually fracturing the metal of the cylinder off. fracturing leaves an Ra or surface finish that looks like mountains and hills when magnified, if you bore it even with the best method tooling skilled craftsman perfectly straight etc you still need to hone approx 3 thou. you are essentially knocking down the mountains and hills to a level where the pistons get oil between them and the wall and rings dont saw themselves away in low hours of use. many pros use honing of 220 300 400 and up to 550 grit finish for dragsters for glide free power. for daily use trikes a med grit hone is fine. want to talk about types of hone grits... aluminum oxide or silicone stones & wet or dry honing? i have many hones and learned the hard way. do not forget 2 stroke port chamfering.

[waynekreitzmann]

Thank you very much

[BOB MARLIN]

The guy I take my stuff to says he tries to leave .002-.003 in the bore for honing. Make sure you measure the piston at different points to find the biggest part. 2 stroke and 4 stroke pistons are made different from each other and some are made intentionally out of round.

[Dirtcrasher]

I have done a lot of surface finish measuring testing and documenting for engineers. sorry half a thou is, even depending on sharpness and shape of your bit and competency of person setting up and doing the machining... not enuff, boring or lathing an (iron) cylinder is actually fracturing the metal of the cylinder off. fracturing leaves an Ra or surface finish that looks like mountains and hills when magnified, if you bore it even with the best method tooling skilled craftsman perfectly straight etc you still need to hone approx 3 thou. you are essentially knocking down the mountains and hills to a level where the pistons get oil between them and the wall and rings dont saw themselves away in low hours of use. many pros use honing of 220 300 400 and up to 550 grit finish for dragsters for glide free power. for daily use trikes a med grit hone is fine. want to talk about types of hone grits... aluminum oxide or silicone stones & wet or dry honing? i have many hones and learned the hard way. do not forget 2 stroke port chamfering.

Best explained answer I've seen in a long time. I too felt less honing could be done however, as he explains it all here, I thoroughly agree with all his information. Thank you for posting