christopher 5 1 Cars Posted March 31, 2008 How can I tell if the bores are worn? SO I have rebuild the bottom end??? I have an iron block engine that has done approx 125k (TU engine) . The engine made good power before it was removed from the engine and the compression test was supposedly fine. The bores look ok no edge and I can still see the honing marks.. Share this post Link to post Share on other sites
danpug 1 Posted March 31, 2008 If the honing marks are still there then thats a good sign. Share this post Link to post Share on other sites
Anthony 1,003 Posted March 31, 2008 Run your fingernail up and down the top 2-3 inches on the thrust side of the bore - you'll feel a lip if it's notably worn Share this post Link to post Share on other sites
ALEX 98 1 Cars Posted March 31, 2008 125K. I'd say they were worn! You can measure the ware using a new piston ring and a set of feeler blades. I think there's a tolerence limit printed in the Haynes Share this post Link to post Share on other sites
Sandy 191 Posted March 31, 2008 0.5mm end gaps on the top rings are the spec limit, but 0.6mm usually still goes fine. If the rings are fatigued, they won't force themselves outwards as well as they did though, which can worsen blow by. Share this post Link to post Share on other sites
christopher 5 1 Cars Posted March 31, 2008 Anthony, I can't really feel any noticeable edge at the top of the bore.. Sandy.. I was really hoping I could measure without having to take the bottom end apart if I don't have to Share this post Link to post Share on other sites
Sandy 191 Posted March 31, 2008 A compression test and leak down test will do that. Share this post Link to post Share on other sites
