10-20 head studs

Oldiron29 · Jan 19, 2012

Hi guy, I am working on repairing damaged head studs and block threads. I had replace some studs years age. The 2 above the tape were from Rice Equipment about an inch of thread on top and bottom. The one below the tape was in block has 1 3/4" of thread on bottom. I think this is wrong, If thread all the way in the stud would be short on top? Am I correct or are the original studs threaded different? oldiron29

Nebraska Cowman · Jan 19, 2012

I think you are right. I think somebody made that bottom stud out of a bolt.

Oldiron29 · Jan 19, 2012

Could be right Howard, This 10-20 has a history of PO mess up"s I am trying to fix. I will not close it up till I no it is right. Have had alot of help from old-F20 oldiron29

JRSutton · Jan 19, 2012

I second the bolt idea. Not just because of the long threads, but because it's silver -not black.

You're probably going to check the head for flatness anyways, but - if you weren't planning on it, it'd be a good idea to do.

Head bolts are designed to stretch only a certain amount for a given amount of torque. Put a mismatch one in there and it's most likely going to be very different, and not tighten in that area the same as the other bolts.

Probably not a big deal but definitely worth checking.

Oldiron29 · Jan 19, 2012

JR, Only seven out of seventeen studs would take torque of 110 # All the rest stripped or pulled out of the block. I will be heil coiling some in block and replacing most of the studs and nuts.
oldiron29

randy hall · Jan 19, 2012

(quoted from post at 23:46:44 01/19/12) JR, Only seven out of seventeen studs would take torque of 110 # All the rest stripped or pulled out of the block. I will be heil coiling some in block and replacing most of the studs and nuts.
oldiron29

ninety foot lbs would be plenty.

Bill Krosnicki · Jan 19, 2012

85-90 ft/lb is all I torque them to. Not sure what kind of torque wrench you have, I had a cheap one once that wouldn't click when it was supposed to, and broke some bolts before I figured out what was wrong.

Oldiron29 · Jan 20, 2012

Bill, I over torqued them to find which ones are bad. From what I thought and others said PO made studs from zinc bolts to soft for studs. I also have bad treads in block. oldiron29

JRSutton · Jan 20, 2012

If that's the case, then I'd love to know how flat the head turns out to be. I wouldn't be surprised if it was badly warped.

Just to be clear, it's not just a matter of them being strong enough to hold (though that's obviously important)

My point is that any time you mix materials, the actual clamping force generated by say 90ft/lbs of torque on each one is going to be radically different between them.

The stud can stretch differently, the threads will deform differently, the friction on the threads can be different, etc. etc.

Since the whole reason for torquing to the same value, and doing it in a particular pattern is to create an even force on the head to avoid warping - it follows that if it's not clamped in place with an even amount of force from each stud, it'll probably warp. Obviously depends on how the head is built too - and how susceptible it is to warping.

I know I'm just preaching to the choir here - but I like to be thorough for people who might be scanning the archives for info.

10-20 head studs

Oldiron29

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Nebraska Cowman

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Oldiron29

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JRSutton

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Oldiron29

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randy hall

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Bill Krosnicki

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Oldiron29

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JRSutton

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