Cylinder ?

Wed Mar 31, 2004 8:51 pm

I was going to rering my 49 cub engine. I cleaned the engine, lapped the valves and honed one of the cylinders. I then took a new piston ring set std. and checked end gap. At the lower point of cylinder the gap is .014 at the top is .062. I checked the other cylinders and all have the same problem tapered cylinders. What do I do? How much can it be bored? This is the first time I have seen a tapered cylinder that is that far out. What would cause that? :? Thanks for the help, Bob k.

Wed Mar 31, 2004 9:10 pm

I can't tell you if you have to bore it out or not. This sounds like more of a ? fore George W, How ever when I was young we had to rebuild one of our "H"s and the machanic said the reason was because of the tapperd bore and that it was caused from lugging the tractor to much. Made sence' "Jack"

Wed Mar 31, 2004 10:03 pm

Bob K, When I did my cubs engine. I had around .045 ring end gap about mid-stroke. (with standard rings). Since I tore everything down on this and said if I went this far. I decided to rebore .20 over .20 oversized pistons and rings. No# 3 and No# 4 cyl. still did not clean up totally. worst wear on edge of wall on side going to the flywheel.Remember when boring over .20 you are only taking .10 off the wall. all the way around I could of went .40!

Wed Mar 31, 2004 10:06 pm

Yes it runs great now .Massive 11.25 Horsepower.Mabe we could make a hemi. "Going to work in my red hemi cub".

Thu Apr 01, 2004 7:14 pm

Bob, check with a good engine rebuilder, they will know how much the y need to go to get it right. You can get up .040 for sure, I think .050, and possibly .060 oversized pistons.