Hey I know this is a longshot but does anyone out there have any idea what the roughness factor (Ra) is recommended for a cylinder either afyer honing or factory? Im wondering because I am trying to spec out a flex hone for my rebuild and suprisingly flex-hone lists their hones based on desired bore roughness. Thanks

 

A 400 grit flex hone would work well for an all around good finish....not too smooth, not too aggressive either.

However these are only for a surface finish....the sizing of the cylinders (relative to piston to wall), out of round, and taper should all be checked before moving forward with the ball hone.

If the cylinders are the right size a 400 hone will leave a nice looking finish and seat a new set of rings if the cross hatch is done properly (not too steep and not to flat). Pay attention to the existing hone for the angle of the cross hatch and adjust the speed of the hone and how quickly you stoke the bore to get a similar pattern.

Good luck....

-Tony

 

First of all thanks for your info, just what i was looking for....

I have a dial bore guage and upon teardown im going to measure the out of round before anything, the engine has 200k on it, but after removing the valve covers and oil pan it looks great...that great golden tint indicating sythetic oil changes its whole life...im optimistic i can avoid the machinist if my piston to bore measurement checks out, im thinking i might have a little bit of wiggle room will file to fit rings so i get a good seal...

Would you recommend Moly rings or some regular steel rings as a better complement to the 400 ball hone? Im thinking steel will like the finer 400 grit even with it being a "DIY" hone job.

 

I also forgot to inquire about your "taper" measurement...this being my first official complete ls motor teardown im curious...I'm assuming you mean taper on the bore from top to bottom? Thanks again...I can really appreciate an "expert" opinion from an engine builder of your caliber...