Farm Equipment - B engine rebuild questions

Print Page | Close Window

B engine rebuild questions

Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=165294
Printed Date: 20 May 2025 at 12:25am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com

Topic: B engine rebuild questions

Posted By: Luke114
Subject: B engine rebuild questions
Date Posted: 24 Oct 2019 at 10:08am

Starting to collect info and parts for a winter project of rebuilding the motor in a '49 B. A couple questions:

It looks like 3 7/16" bore is the normal sleeve/piston kits available rather than 3 3/8". Any reason for this other than increasing displacement? Is there some other reason why nobody offers the original bore?

Also wondering if its worth the trouble to fit modern lip seals on the crank rather than the felt and cork. Sleeves or filling the oil grooves with JB weld are the two methods I've read about. This will be a working tractor, not a display, so I'm not going to sweat a drop or two weeping from the seals, but I'm not sure what to expect from new cork and felt.

Incidentally, this was a motor that was completely (top and bottom end) filled with water from years of sitting in the rain. The sleeves are pretty trashed with rust on top, but amazingly the bottom end looks pretty good. Torn down except for the crank/cam, so hopeful I don't find any major issues.

thanks!

Replies:

Posted By: Sugarmaker
Date Posted: 24 Oct 2019 at 11:59am

Luke,

Welcome! I would make sure it has not froze and cracked the block as a next thing to check.

I have used speedi-sleeves to cover the crank grooves.

Sounds like a good project. Not sure on the overbore, seems to be pretty standard now.

Regards,

Chris

-------------
D17 1958 (NFE), WD45 1954 (NFE), WD 1952 (NFE), WD 1950 (WFE), Allis F-40 forklift, Allis CA, Allis D14, Ford Jubilee, Many IH Cub Cadets, 32 Ford Dump, 65 Comet.

Posted By: WF owner
Date Posted: 24 Oct 2019 at 3:39pm

If it had that much rain water in it, I would have the head checked for cracks, too. No sense in spending a lot of time and work if it has cracks..

Posted By: Gerald J.
Date Posted: 24 Oct 2019 at 5:38pm

The shop manual should help with details:

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

Gerald J.