39 JD B Cylinder Sleeving Misalignment

Is is possible to attempt another sleeving? Can he just hog these out and try again or would that create other problems? He has done hundreds of these and claims the current sleeves will not be a problem. But I do not want to cause alot of undue stress on my crank arms, piston pins or crank shaft.

I was hoping to find a way to salvage this one. My plan is to mount it up and measure the amount of side to side swing on the crank arms. Ideally there should be none or just a few mils. Do you think it is possible to try sleeving agian or is that just plain impossible? My thought was to maintain a reference point on the crank end relative to these sleeves as that is where he lined up on the original material and then go down and find the center on the compression chamber. Line those two center points up install and bore out another sleeve. Possible???

The machinist I use lined everything up off the crank case end face of the block. Found the original cylinder center line at the least worn section of the cylinder and bored it out. He used 3/32 (0.0937) sleeves. His boring machine is a Rottler (spelling??). This fellow is no slouch or newby he is very well respected, done this for years and knows these old engines. Every body who owns an old tractor in this region brings their work to him.

This block had never been bored / sleeved before. I have had this tractor for 23 years and have re-built it once before but did not sleeve it at that time. The block was all original. Don't know the casting number but I will check when I get it from his shop.

I sleeved it because I lost compression on the #2 cylinder while harrowing. Every time the #2 cylinder hit I could see the crankcase oil pressure gage spike. I broke it down and got the cylinders out in four hours, checked the IDs on the head end and got 5.017 inches vertical and 5.006 inches horizontal. The crank end IDs were right in spec. The number 1 cylinder was better but not that much. With that big of an oval I knew that just rings would not help all that much. I checked on over sized pistons but none can be found for these transition year tractors. So I decided to go for a complete rebuild including sleeving and a valve job on the head.

I am beginning to think that the original casting was off slightly around the combustion chamber end. As you say this is a 64 year old casting and it may be off. I also have significant end play on my crank leading me to believe that the original cylinders were "off" slightly causing excessive wear on the crank main / thrust bearings.

If these sleeves are perpendicular to the crank end face and on center with the originals they should line up just fine. I plan to mount it up and check. I will go real slow and make sure I don't bind anything up. I will let you know how it works out. Send me an e-mail at rjjgates@bossig.com and I will send you pictures of the work when I get them back.

Thanks again for the great advice.

Rob

gave you the wrong numbers on the old cylinders they were 4.517 and 4.506. Thats what I get for trusting my memory.