Coating Cylinder Liners

48lesco · Post by **48lesco** » Fri Apr 20, 2012 3:37 pm

Dropped the liners out of an old block last night to use in my good CB77 block. Want to tighten up the clearance on the .25-over pistons and install the oversize pins. Two issues:

1) The cold liners dropped right into the warm block but stuck up .007-.011" above the deck. On closer inspection, the lip was about that much thicker than the old liners I replaced. Looks like Honda machined those in place and they are all a little different. Could have it skimmed, but are those liners in there tight enough for that?

2) Should the liners be coated before they're dropped in? Did a search and found a post from about 5 years ago where Krylon clear was used. Any other thoughts?

Thanks!
-48

mike in idaho · Post by **mike in idaho** » Fri Apr 20, 2012 6:39 pm

I wouldn't think you would want to put anything on the out side of the liners, that would hamper heat transfer.

mike in idaho · Post by **mike in idaho** » Fri Apr 20, 2012 6:39 pm

I wouldn't think you would want to put anything on the out side of the liners, that would hamper heat transfer.

G-Man · Post by **G-Man** » Sat Apr 21, 2012 2:30 am

When I took my blocks with newly installed liners to the borers, they recommended two things.

a) giving the liners a final push down on their hydraulic press
b) skimming the top face of the block

I didn't use anything between liner and block although a pair of NOS liners I found did have some kind of preservative coating which I left on.

On point a) above the guys said that when liners are put into a hot cylinder they get pushed back up a little as the block cools down. Hence giving them a final push. Who am I to disagree.

G

48lesco · Post by **48lesco** » Sat Apr 21, 2012 8:59 am

Thanks for the replies! - While the block was still warm, I took the liners back out and measured the thickness of the lip on the liner, and the depth of the recess on the block and the lip was .010" thicker than the recess. An .010" stick-up is too high so I will have to have the block skimmed if I want to use those liners in that block.

G - That steel is pretty hard, and the liners aren't all that tight, so I was a little worried about them moving when the mill hits them but I guess your guys didn't have a problem skimming them assembled the way you did. I saw some pics from an old post of yours and they looked good! The coating on the NOS parts is interesting, maybe just to prevent corrosion? I wouldn't think you would want any type of lube on them, in fact I washed everything in soap and water before I heated the block (also required in order to use the upstairs oven a second time).

Mike - That's a good point about heat transfer. I was thinking about something along the lines of a thermal glue that would increases contact between the two surfaces and increase heat transfer although I doubt that was done in the sixties.