Allis B engine rebuild

I'm gonna start my 1st rebuild in my AC B on Monday. I have new sleeves, pistons, and bearings. I got the crank grounded down to .020". Any advice to give a newbie? Definitely gonna take my time with it.

Clean everything up. After you get the most of the old grime off, use brake cleaner to finish the cleaning job. 

I always set bare new sleeved down in the hole and make sure they will turn by hand 360º before installing the O rings. I use a die grinder with a flapper drum to clean the bottom bore. I have had one area the took more flapper sanding to get the sleeve to set down square and turn 360º. If they are not turning I use bluing and set them down without turning to read where the bluing is being scraped off.

After the sleeves are set and held down with a short 7/16" cap screw with a washer I put each ring from a set down in the sleeve and check the end gap with a feeler gage. I have found in a complete boxed ring set a pack of rings with an over lap rather than a gap.

Even though you have a fresh ground crankshaft with matched bearings check each bearing with plastigage for clearance. Making sure the bearing is properly lubed and torqued, rotate the crank to make sure turns free before installing another bearing. Main and rod caps are not new and could have been distorted and could be a couple thousands wider at the bottom than the sides causing them to be tight with a good reading.

   

steve(ill) wrote: you had the crank ground... AND you got matching bearings for it from the grinder ? no shims needed if you MATCH the new bearings to the crank.   did they machine the rod journals or just the mains ?

 Grinding the crank and getting matching bearings does NOT mean you can eliminate the shims. Only line boring will allow to assemble without the proper shims.

Shop manual is at:

http://geraldj.networkiowa.com/Trees/Allis-Chalmers-G-B-C-CA-Service.pdf

Gerald J.

The machinist said to get .020" bearings. I got the rebuild kit from jim danforth @ oktractor. Did new valves and work on the head.

WF owner wrote: A bit of advice.  After you open your -.020 bearings, check them to make sure they are the right bearings !!! I know this from a very recent overhaul of a G226 (Thank you DrAllis) !  My machinist checked the crank on my engine and said it would be fine with new standard main bearings. I ordered a set of standard bearings. The box said standard bearings. I put them in and just snugged the main caps. I couldn't turn the crankshaft. After trying some other things (removing the cam) DrAllis suggested I check the size of the bearings. I looked again at the box and told him the box said standard. He repeated to check the actual bearings.  Guess what ! The bearings said .020 ! For some reason the bearings were in the wrong box. The bad part is that someone probably got a box that said .020 and I bet his engine turned very easy (for a while!). DrAllis told me it happened tp him before. I will ALWAYS check them in the future.  I now have a set of .020 bearings for a G226 that I will never use and I'm out $120 for a new set of standard bearings. If you have the right bearings, you should use a full new shim pack for each bearing. Check your clearance with Plastigauge to be sure ! Sorry so long!!!

thanks for the warning. I'll check them then. You said a full new shim pack for each bearing. What's considered a full pack? Might be a stupid question but im not close to my manual.

a "SHIM PACK".... is normally a few shims together that measure .006 inch... A PACK goes on each bearing cap bolt........ don't let the bearing touch the shim, just the CAP face.

Dick. Even though you have a fresh ground crankshaft with matched bearings check each bearing with plastigage for clearance. Making sure the bearing is properly lubed and torqued, rotate the crank to make sure turns free before installing another bearing.   [/QUOTE wrote: X2 I always plastic gauge my bearings to .0003. Never spun a bearing or had knock. After I lubricate the sleeve and put on the o rings, I take a round screwdriver and slip it under the o ring and

Edited by nella(Pa) - 01 Sep 2019 at 11:33am

nella(Pa) wrote: I always plastic gauge my bearings to .0003. Never spun a bearing or had knock.

 I think you meant .003, that extra 0 would make it pretty darn tight

That is how rich people do things. They used shims in the first place because they knew everyone was not rich!

I line bored and resized the rods on my C for pulling. Been poor ever since.

My old Chevys were shimmed also.

Dick L wrote: That is how rich people do things. They used shims in the first place because they knew everyone was not rich! I line bored and resized the rods on my C for pulling. Been poor ever since. My old Chevys were shimmed also.

I'm definitely not rich!!!! Lol

When I rebuilt Lena, the 35 WC, it had been rebuilt at least twice before and the main bores were not round at all. I put .006 shim in them and used a good Sunnen hone to make them real close to round. Everything cleaned up except maybe an 1/8 inch of the diameter right at the parting line.
 I had the crank ground and dropped new bearings in and it checked between .0025 and .003 with plastigauge and rolled over fine. I expect it to outlive me. It's only had maybe 100 hours on it since the rebuild .

DaveKamp, Your sarcasm meter is defective. After buying an overhaul kit many do not have extra money laying around to put out three to four hundred into line boring, resizing rods or other costly items.

When I was into stock car racing with two little ones at home I headed home after stopping at the parts store. I looked over in the seat beside me and spotted a note my wife had given me that morning. It said stop and get two gallon of milk on the way home. I had spent all my cash and had to stop at a local store and charge the milk. That ended my racing dreams. Food and shoes for my little ones instantly became more important than the thrill of turning left in a cloud of dust in front of a grandstand of people hoping I would be taken away on a stretcher.

I assume people starting into old tractors have a passion with limited funds as I did.


Allis called out the shims as a way to get more life out of the engine. It was also used for that in the 1920's auto engines. All three of my 1920's Chevys have shimmed rods.