Farm Equipment - Valve grinding

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Valve grinding

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=176460
Printed Date: 19 Jul 2025 at 10:08am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com

Topic: Valve grinding

Posted By: TMiller/NC
Subject: Valve grinding
Date Posted: 03 Dec 2020 at 6:05pm

Was gifted an Allis B with the head off, appears to need the valve seats and valves ground, do you fellows repair heads yourselves or send them out. The last one I sent out 5 yrs or so ago cost $180, would like to hold the expense down on this tractor, as I know of other work it needs. Thanks, Tim

Replies:

Posted By: steve(ill)
Date Posted: 03 Dec 2020 at 6:10pm

you could try lapping and see what it looks like.. Maybe dont need recut... If you dont have a lapping tool, i have used a 1/4 inch rubber gas line pushed over the valve stem, the a 1/4 inch stud in a hand drill and push the hose over it. put lapping / grinding paste on the valve, oil the stem, push in the hole and connect to the drill..... bump it slowly so it rotates and grinds/ laps the seat... you dont want to go FAST or run the stem dry of oil... Do it slowly for 2-3 minutes and inspect you work........ Its not rocket science, just a slow speed, low HP motor.. Dont have to be perfect, if your on a budget.

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Like them all, but love the "B"s.

Posted By: TMiller/NC
Date Posted: 03 Dec 2020 at 6:41pm

Thanks Steve, I'll try that, the #4 exh is pitted so may take some time on it. Tim

Posted By: steve(ill)
Date Posted: 03 Dec 2020 at 7:08pm

some will tell you that you cant do it this way. I dont think i would do a high HP truck and want it to last 250,000 miles, but thats not what your building... Go to the hardware store and get some COURSE grinding compound and do that.. You might spend a half hour on a BAD valve.. Just go SLOW and keep oil on the stem.. You will be able to tell after a few minutes if the seat it trashed to the point that it will never cleanup.

https://www.youtube.com/watch?v=l8_dVrKz5BI" rel="nofollow - https://www.youtube.com/watch?v=l8_dVrKz5BI

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Like them all, but love the "B"s.

Posted By: Krazy Karl
Date Posted: 03 Dec 2020 at 7:27pm

Check the head to see that is flat and that it doesn't need to machined. Before doing all that work. If have to send off for that

Posted By: MACK
Date Posted: 03 Dec 2020 at 8:57pm

Just tighten the chuck to valve stem . No need to mess with a Rubber hose that will twist and come off. MACK

Posted By: ac fleet
Date Posted: 04 Dec 2020 at 9:53am

x-2 on chuckin the stems in drill! -- done many that way in a hurry. I now have an old grinder so I run them thru it now.

Head grinding is the other problem!

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http://machinebuildersnetwork.com/

Posted By: jlbintn
Date Posted: 04 Dec 2020 at 11:23am

I don't have the expertise, or the tools, to do it myself. I sent my head to a shop, seven weeks and $276 later, it's good to go. The valve kit was another $120, so almost $400 into the whole repair, but it's done.

Posted By: HoughMade
Date Posted: 04 Dec 2020 at 2:28pm

I lapped the ever-lovin' bejeebers out of my B's valves, most especially from the 2 cyliders which had rusted and locked up the engine. I figured I would try to get it running and if needed a real rebuild, I would cross that road when I got to it.

Well, 3 years later, she's still running like a champ. No rebuild yet.

I wish I had pictures of the "before" lapping. There was slight pitting on the seats for one cylinder (both valves) and moderate pitting in the other cylinder, but both seal up and make decent compression.

[TUBE]kv-HXI-r3eM[/TUBE]

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1951 B

Posted By: steve(ill)
Date Posted: 04 Dec 2020 at 3:49pm

YEP... your not building a race car.. Just the basics and it will run fine !

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Like them all, but love the "B"s.