Allis C camshaft swap
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=208376
Printed Date: 01 Oct 2025 at 11:12pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: Allis C camshaft swap
Posted By: SWPennTom
Subject: Allis C camshaft swap
Date Posted: 01 Oct 2025 at 7:03pm
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Troubleshooting an engine knock on a '49 C, inherited from my Dad. ( It also won't start when it's hot - have to wait for the engine to cool down to restart it ) I was at a antique tractor show in August so I could talk with owners of restored C's, listen to their engines run and get advice. The knock in my CE 95394 engine is not normal, their A/C's engines did not knock. Recommendations were bad crank bearing(s) and/or worn camshaft causing valve clatter. Back in 2017, Dad said the engine had been rebuilt, without saying when. Currently it leaks a significant amount of motor oil from the front crankshaft seal, slightly less from the rear seal at the flywheel. The engine is off the tractor now, and yes, it looks like new cylinder liners and pistons. Also the cylinder head has new valves and the new valve guides. I haven't pulled the crankshaft off yet. The camshaft appears to be the original, to my untrained eyes I think it looks worn. I'm getting a less worn replacement. Question for the mechanics out there : Do I need to have the tappets machined to make them perfectly flat again for the apparently unused replacement camshaft? Any tips on installing not mentioned in the manual are welcome. Pictures are from #1 & #4 cylinders.
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Replies:
Posted By: Les Kerf
Date Posted: 01 Oct 2025 at 8:49pm
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Those cam lobes are badly worn and the tappets most likely are as well; I would definitely want the tappets to be re-surfaced. |
Posted By: steve(ill)
Date Posted: 01 Oct 2025 at 8:53pm
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a real KNOCK is crank / rods / piston pin area... Worn cam shaft with excess valve clearance will make a RACKET , but normally not a Knock... Cant tell about most problems without actually takeing MEASUREMENTS... but i would agree, the lobes of that cam do look like they are worn off on the edges... Tappets need to be looked at close or measured to determine if they need refaced..... I have done several of the B engines over the past 20 years and never had one that i thought the tappets were bad enough to reface. If you have a service manual, make sure to read the part about how the connecting rods go in the block, which way they face... If you dont have a book, we can give you some advice on that.. Its a pretty basic engine getting 25 HP from 125 CID.. If you have rebuilt any motor what so ever in the past, this one will be pretty basic. ------------- Like them all, but love the "B"s. |
Posted By: steve(ill)
Date Posted: 01 Oct 2025 at 8:55pm
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Did you happen to look at the oil pressure gauge prior to tear down ? Pulling the pump apart and block sanding the end plate to tighten up the clearances can give you a couple extra psi on an old engine. ------------- Like them all, but love the "B"s. |