Head bolts #
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panz4ever
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Head bolts #
I am finally getting ready to send my 49 EL motor out for build up. I was going through my collection of headbolts and found 7 that are marked CP1041. All others are marked CP1038. Can someone explain the difference for me please.
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Cotten
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Re: Head bolts #
I think Palmer's lists the distinction by vintage.
(My copy is always at the shop...)
....Cotten
(My copy is always at the shop...)
....Cotten
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panz4ever
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Re: Head bolts #
Cotton, Palmers says that 48 and later OHV motors start with plain head, progress to 1035 over CP to 1038 over CP marked bolts. At what dates is not clear. No mention of 1041...unfortunately
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FlatHeadSix
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Re: Head bolts #
Panzr4ever,
I can't tell you everything you need to know about your bolts but here is a little info:
in the early days when labor was cheap the motor company made most of their own hardware in-house, those are mostly plain head. they were pretty fond of 24 thread per inch stuff in various diameters which was not very common from outside suppliers.
right after the war when production went way up they started buying from outside vendors. The "CP" on your bolts stands for Chandler Products, still in business today in Cleveland, OH
The numbers indicate the alloy used; all of the "10" series like 1035, 1038, and 1041 are carbon steel. Can't tell you exactly when they switched from one to the other. The 1041's you have may have come from a hardware store or somebody's junk drawer during a past rebuild, CP marked bolts were heavily used by the auto industry during the same period.
Metallurgy was a factor in selecting headbolts because of the tendency for them to "stretch" when tightened to required torque specs. I would think that any grade 8 bolt of the proper dimensions would work just fine as long as it was torqued correctly to begin with and rechecked after break in.
Are AMCA judges really that picky?, are they going to stand on their heads or use little dental exam mirrors to look at the heads on your headbolts?
I can't tell you everything you need to know about your bolts but here is a little info:
in the early days when labor was cheap the motor company made most of their own hardware in-house, those are mostly plain head. they were pretty fond of 24 thread per inch stuff in various diameters which was not very common from outside suppliers.
right after the war when production went way up they started buying from outside vendors. The "CP" on your bolts stands for Chandler Products, still in business today in Cleveland, OH
The numbers indicate the alloy used; all of the "10" series like 1035, 1038, and 1041 are carbon steel. Can't tell you exactly when they switched from one to the other. The 1041's you have may have come from a hardware store or somebody's junk drawer during a past rebuild, CP marked bolts were heavily used by the auto industry during the same period.
Metallurgy was a factor in selecting headbolts because of the tendency for them to "stretch" when tightened to required torque specs. I would think that any grade 8 bolt of the proper dimensions would work just fine as long as it was torqued correctly to begin with and rechecked after break in.
Are AMCA judges really that picky?, are they going to stand on their heads or use little dental exam mirrors to look at the heads on your headbolts?
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panz4ever
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Re: Head bolts #
panzerama, this ain't going to be no AMCA judged "trailer queen" that never gets dirt on the tires (no offense to those that are AMCA judged and riders!). I just happened to be going through head bolts, noticed the difference and was wondering why. It was one of those.."What have I got here" moments when the whiskey in the glass got low.