Cracked Engine Block - repair options?
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=195043
Printed Date: 10 Aug 2025 at 4:23pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: Cracked Engine Block - repair options?
Posted By: Dale (Stonelick)
Subject: Cracked Engine Block - repair options?
Date Posted: 08 May 2023 at 8:54pm
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I discovered that my newly acquired 1944 Allis C has a cracked engine block - see picture (it is outlined with a black marker). It's an eight inch horizontal hairline crack that runs through the engine block coolant drain plug hole. Asking for suggested economical repair options. I checked the internet (and an Allis forum post dated 1/17/20) and found some options listed: replace block, weld crack, bolt on a flat plate with gasket and RTV or Permatex, grind out crack and seal with JB Weld, Belzona 1111 Super Metal, or Aluma patching material, or add K-Seal to the coolant. Since the crack runs through the coolant drain hole, I think it adds to the complexity. Will appreciate any suggestions.  ------------- 1951 CA - 1944 C - 1949 B - Kubota M6800 |
Replies:
Posted By: DrAllis
Date Posted: 08 May 2023 at 9:21pm
| Different block. Welding would be second best, but will leak (in time) even if you use some type of sealer. NOTHING IS WORSE than getting a tractor all fixed up and painted and then in a couple of years the damn block is leaking. What do you think that will do to the resale value ???? |
Posted By: DiyDave
Date Posted: 09 May 2023 at 4:18am
First step I would do is to find someone who can magna-flux the crack, to find the ends of the crack. Then use the lock and stitch shown in this video, make sure not to drill through the back of the water jacket, though. Once its repaired and back in service, some blue devil block sealant, added to the coolant per the instructions on the can. As the Dr said, first check to see if you can find a better block... https://youtu.be/Pq0wfU4ZaKk" rel="nofollow - https://youtu.be/Pq0wfU4ZaKk ------------- Source: Babylon Bee. Sponsored by BRAWNDO, its got what you need! |
Posted By: WF owner
Date Posted: 09 May 2023 at 5:04am
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I had the block on my WF welded, because it was my grandfather's tractor and I want to keep it as original as possible. Unless you have a reason, I would go with Doc's recommendation of a replacement block. With machining, parts and labor, a complete engine rebuild is going to be $2000 or more. Why start with a cracked block?
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Posted By: PaulB
Date Posted: 09 May 2023 at 6:32am
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In today's world, finding a competent person with the skills to to do a weld repair on a cracked block is practically impossible. In years past this was not the case. With what you would spend to have a block thoroughly cleaned, magnafluxed then repaired, would buy you a truckload of usable blocks. ------------- If it was fun to pull in LOW gear, I could have a John Deere. Real pullers don't have speed limits. If you can't make it GO... make it SHINY |
Posted By: Jgranat
Date Posted: 09 May 2023 at 10:35am
| OrangeKnight has a bunch of b/c trractors he is parting out in the classified section, why not investigate that at least. |
Posted By: JC-WI
Date Posted: 09 May 2023 at 11:17am
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Get it magna-fluxed. Didn't see it leaking before? Have seen nickle rod weld where the crack was V and weld an 3/4inch and peen the weld till it was cool and then weld again until done. Seen one engine that was laid on it's side, crack was 'v'd a little bit and a cleaning acid was poured on and then heated the block enough for soldier to flow and after 50 years, it is still holding. ------------- He who says there is no evil has already deceived himself The truth is the truth, sugar coated or not. Trawler II says, "Remember that." |
Posted By: modirt
Date Posted: 09 May 2023 at 5:53pm
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Several potential donor C's on Auctiontime. Shop where the D15 is sitting has a C that i hear is for sale. they say it was running when it was parked, and has a 2 row cultivator on it. Central MO. If interested, I'll investigate further.
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Posted By: HudCo
Date Posted: 09 May 2023 at 9:09pm
| their is only a few of us left with the skilss to do it so it will last but at a 120 an hour i would recomend a used block |
Posted By: Codger
Date Posted: 09 May 2023 at 11:17pm
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There are still a few of us "old guys" that will do that type of repair. We are however getting fewer as time marches on. It is expensive to perform correctly and even I would look for a donor cylinder block and resort to welding as a last resort to salvage if no other means. That block looks to have frozen from lack of anti freeze solution so it's not a thermal expansion and contraction crack which is much more difficult to facilitate a lasting repair upon. ------------- That's All Folks! |
Posted By: Lon(MN)
Date Posted: 10 May 2023 at 6:12am
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I have six bare blocks with no cracks. $100 each. ------------- http://lonsallischalmers.com |
Posted By: DonDittmar
Date Posted: 10 May 2023 at 6:28am
You cant begin to have a block repaired, either welded or lock n stitch, for 100.00. Buy a used block from Lon LOL ------------- Experience is a fancy name for past mistakes. "Great moments are born from great opportunity" 1968 D15D,1962 D19D Also 1965 Cub Loboy and 1958 JD 720 Diesel Pony Start |
Lon(MN) wrote:Posted By: Dale (Stonelick)
Date Posted: 11 May 2023 at 9:08am
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Thanks for all the expert advice. Surprised about the difficulties and cost of a weld solution. Hoping that a block replacement is not too far above my abilities. JC-Wi ... I kick myself for not realizing the block had potential issues before getting the winning on-line auction bid. I did get a chance to see the tractor during a limited pre-auction inspection - noticed the pealed paint & rust beneath the carb, but didn't connect the dots. The deceased owner's son said that this tractor was started about 5 years ago (not the case at present), so I assumed this was a diamond in the rough. The owner had about 25 old tractors in various states of repair when he died. Others ... No thanks at this time on leads for a replacement block. I live in SW Ohio, and will attempt to find something closer to home, after I get it running. ------------- 1951 CA - 1944 C - 1949 B - Kubota M6800 |