Torquing D15 Head Bolts
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=194923
Printed Date: 30 Nov 2024 at 6:32am
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Topic: Torquing D15 Head Bolts
Posted By: modirt
Subject: Torquing D15 Head Bolts
Date Posted: 01 May 2023 at 4:16pm
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On Series II with 160 engine, manual says to torque them all to 80 to 85 foot pounds. All 12 of them. Except all the bolts are not the same size or spacing. On right side of engine, there are fewer and larger bolts. Does anyone torque those more? If so, how much.
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Replies:
Posted By: steve(ill)
Date Posted: 01 May 2023 at 5:10pm
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the 1/2 inch bolts can go close to 80.... the 7/16 bolts are more like 60.
here is a reference... head bolts are similar to grade 8..  ------------- Like them all, but love the "B"s. |
Posted By: ChillyB
Date Posted: 03 May 2023 at 8:57pm
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What a fastener can accept before yield is not the point with head bolts. What matters is even tension. Bolt tension is a function of torque for a given thread pitch regardless of size. I don't know the thread pitch for your bolts. My first year D14 has all 7/16 bolts. My recommendation is to torque all bolts the same. The difference between tension on a 7/16-14 vs 1/2-13 probably isnt much if torqued to same value. I torqued my head to 60 ft-lb and had water in oil. Pulled to 65 ft-lb and no more problems. For what it's worth. And I used new grade 8 bolts, which could have accepted more torque but that is no reason to actually pull them that hard. |
Posted By: modirt
Date Posted: 04 May 2023 at 7:09am
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This D15 has 7 - 7/16 bolts down left side, and 5 - 1/2 bolts down right side. The goal was to get compression of head gasket even. D15 manual says to do them all to 80 to 85 foot pounds. Somewhere I seem to recall there is another Allis engine with two sizes of head bolts and they had different torque specs. More for the larger ones. If doing them even is what works, then that is good enough for me. |