Allis Chalmers C valve cover stud bolts

[Larry Hardesty]

I am putting back together the engine for a 1942 Allis Chalmers C. It looks like the two studs that hold the valve cover on are different. One has coarse threads at both ends and the other has coarse threads at one end and fine threads at the other. Why is this so? Or did I mix up some studs somehow..don't think so, but for the life of me I cannot figure out AC made the studs different (and they have different part numbers in the parts book). Usually something like this is done for a purpose, and I do not want to mess something up. Thanks in advance
 

[old]

I would have to look to be sure but that maybe a case of some one messed up the treads a long time ago and then used a course die to fix the problem on one of those studs. I know I have at least 4 C heads around since I have to running Cs on the place plus a couple c parts tractor
 

[Larry Hardesty]

Well, the coarse threads seem to screw into the head okay, and three of the four ends of the two bolts are coarse threads. But who knows that may have been done over the years. I think the head shows evidence of being overhauled two or three times previously. Thanks Larry
 

[midwesternhayfarmer]

On the B one stud is different to act as anoil channel for the rockers.
 

[Dick L]

All should have course threads on the end that screws into the head. All should have fine threads on top. One will have the groove for oil to get up to the rocker arm shaft. You might have a manifold stud mixed up. Also might be someone else mixed it in before you.
 

[Larry Hardesty]

I think these are too long to be manifold studs. They are probably 5 inches long. Ummm...and I not seeing grove in them for oil.

Thanks

Larry
 

[old]

One should have the oil groove or you will have a problem down the road
 

[Dick L]

The head will have an oil line going to it from the oil pump. The hole the fitting screws into that is attached to this oil line is drilled to the center of the head under the hole where the stud with the groove screws into. That is how oil gets to the top of the head. Without that stud you have a dry, un-oiled, rocker arm/valve assembly. Easy detail to follow while understanding how your engine gets its lubrication.
 

[Larry Hardesty]

Thanks to old and Dick L. Looks like I need to find the right stud somewhere.
 

[old]

I have one or 2 heads laying around and I am sure that both would have that stud on them. My e-mail is always open
 

[Larry Hardesty]

Did you get my e-mails?
 

[Larry Hardesty]

Found one locally, Thanks

Larry