Head bolt recommendations
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=194472
Printed Date: 10 Sep 2025 at 4:29am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: Head bolt recommendations
Posted By: pungobob
Subject: Head bolt recommendations
Date Posted: 06 Apr 2023 at 5:41pm
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Well I got extremely lucky and only broke four of the head bolts on my G. Now I need some help from the G gurus here on the forum. The bolts I was able to remove are badly corroded and will not be going back in my engine. My question: what is the best bolt material should I use to replace the bolts? Grade 8, stainless steel? Any recommendations will be greatly appreciated.
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Replies:
Posted By: steve(ill)
Date Posted: 06 Apr 2023 at 5:43pm
i bought a disassemble "B" motor 20 years ago... had no head bolts.. I just bought grade 8 steel bolts and put it together.... 20 years ago.
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Like them all, but love the "B"s.
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Posted By: Jim.ME
Date Posted: 06 Apr 2023 at 6:47pm
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Not stainless. They are softer than most realize and threads gall easily. Use Grade 8
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Posted By: pungobob
Date Posted: 06 Apr 2023 at 8:08pm
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Thanks Jim and Steve. I was in the marine industry for a lot of years and completely understand the galling tendency with stainless. Grade 8 it is. Thanks again for the help.
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Posted By: DrAllis
Date Posted: 07 Apr 2023 at 6:38am
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Run a bottoming tap down each and every head bolt hole in the block. Rinse/wash out with brake kleen and use compressed air to blow out remaining any dirt. Wipe grease lightly on new head bolt threads for lube. Torque to spec. Retorque after a few hours of running time when engine is stone cold.
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Posted By: pungobob
Date Posted: 07 Apr 2023 at 7:07am
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Thanks for the reply Dr Allis. I have got the bottom taps on hand. Waiting on my torch tanks to get filled so I get heat up a couple of the broken off bolts and studs to facilitate getting the head off. No need to get in a hurry.
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