10-20 head stud

I saw the post from Ben about the H head stud oops! I have posted this some time ago, and than pushed the 10-20 to the back corner of the shed.
I have never come up with a good method for a fix. I purched this 10-20 as a none running barn find. Got it running and drove it around the yard ran good. Parked near shed and went in for lunch. came out to start and #3 was water locked. PO had machined and ported head for over size valves I think for "pulling". Valve seats cut into water jacket.
I had the head fixed and tested no leaks. When I removed head, the gasket was siliconed on both sides. Found 6 or so head studs with poor threads, so I sealed and replaced them. When torquing 2 or 3 studs do not hold in block. I am now thinking PO broke studs in block and did poor job retaping.
What would you guys do????? oldiron29

Oldiron, I would tend to agree with you. There are a couple of ways to attack this in my opinion. The easiest one has some risk to it that you will have to remove the head again if it doesn't work. for the studs that "don't hold" well, will they at least slightly snug? If so, get some JB weld. Chase the threads again in those holes with the correct size tap. Apply the JB weld to the holes and also the studs. Install studs to just slightly snug.

Let it setup for 24 hours, and then go ahead and install the head again.

Other way would be to drill and tap the holes out to the next size if there is enough meat in that area of the block. Have a machine shop turn down the new bolts so you have the larger thread going into the block, and the correct size for the rest of the bolt. You will have to cut new threads onto the custom bolts, but should work just fine. Also, you will probably have to use Locktite for the custom bolts to hold them in the block, as they will not have a shoulder to rest on for tight, and will turn when you go to torque the head on. You could also use a punch to peen "lock" then in place, but be careful not to over peen them.

Last option would be to use a Helicoil if you can find the right size. also, a good choice.

Yeah - I'd find a good engine shop in your area and see what sort of options they can offer.

If you go oversize with a different stud - be sure whoever's doing the work understands engines. A stud is designed to have a certain amount of stretch when you torque it (or limited stretch depending on how you look at it).

You don't want somebody to just chuck up whatever they've got laying around to turn you a new stud.

To your advantage, these aren't race car engines, and the tolerances are a lot looser, but still. You don't want a head stud that stretches like a rubber band. You could end up warping your head.

Tom, the head has been off 3 times allready!
when your torquing to 90-95# I don"t think the heilcoil will hold. I have thought about the custom studs and retapping block. I need a test for torque before I set the head. It is no fun to put the head back on with new gasket and than have a stud fail. This will be my late winter project. So I need to get my game plan started now. Mabe someone has run inti this kind of thing before. oldiron29

JR, When I pull it in to the shop and pull the head the first thing I am going to check is if the head is warped. I think if PO was building a "pulling tractor" mabe he had the head or block shaved? Or the head is warped. That is why PO over torqued head and stripped or broke studs.
Oldiron29

I have heli coiled a few head studs that run into the water jackets with good sucess.If you do this,be sure and use some "blue devil" block sealer when you are done.Get it at your MAJOR parts places.

Another option which is great is a threaded insert from McMaster- Carr.

The advantage with these is they are not the "next size up" in threads like a heli coil.If your threads were BADLY damaged,the appropriate heli coil for that bolt size MIIIIIGHT not be tappable to the heli coils threads ???? The only limiting thing with these is if the headbolt sits close to a cylinder or sleeve it might not allow for the newer,larger diameter of the oversized inset to fit????



http://www.mcmaster.com/#threaded-inserts/=f1m70p

heres what i do. with over a dozen pre 39 engines built, it works.


HELICOIL!


ive had to deal with broken studs all the time since ALL the head studs are open to the water jacket. Ive had one block that alomst half the studs broke off and after trying to wled nuts to them and have them snap off again, i just set the block in the bridgeort and drilled out whats left of the stud. over bore it, re-tap it and stick a helicoil in it.

if you think it wont hold, ill let you come over and put a tourque wrench on an F-30 i built with 8000 foot pistons and .030 shaved off the head and tourqued to 125 ft pounds

only .030", heck I got one somebody took over .220" off of, yeah its pretty thin between the passages....

(quoted from post at 10:20:12 11/22/11) only .030", heck I got one somebody took over .220" off of, yeah its pretty thin between the passages....

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i think i might know that goofball!!! lol

i did .030 just t clean it up good. cant take too much off with 8K pistons

I would go with the helicoils too. Hal

Old F-20 and RobgIN, After you had shaved the head you put washers under the rocker posts?
or your push rods are to long? Ok I have someone now that likes heilcoils as long as it is proven as OldF-20 said thats good for me. oldiron29

(quoted from post at 15:21:10 11/22/11) Old F-20 and RobgIN, After you had shaved the head you put washers under the rocker posts?
or your push rods are to long? Ok I have someone now that likes heilcoils as long as it is proven as OldF-20 said thats good for me. oldiron29

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.030 isnt anything at all to worry about. you have almost 1/4 of an inch of adjustment on your rocker arms. when you re-install the head, go through and adjust them a bit loose til you run the engine and warm it up. at that point set your final gap on your rockers!

I did have to use washers under the rocker pedestals to shim up the rockers to get adjustment for valve lash. Other than that no problems, and it has 5000 ft hi altitude pistons in it.

I worked on Cummins Diesel engines, in line sixes such as NTC350 & big cams. It's been a while ago, but we always used key lock threaded inserts, installed with green (cam gear) loctite made for Caterpillar.
This is how we repaired diesel blocks for head bolt holes & we torqued these way higher than your application.
one example:
http://www.directindustry.com/prod/carr-lane/key-lock-threaded-inserts-11751-412560.html

A good machine shop should be able to acquire & install these for you.

(quoted from post at 04:54:37 11/22/11) I saw the post from Ben about the H head stud oops! I have posted this some time ago, and than pushed the 10-20 to the back corner of the shed.
I have never come up with a good method for a fix. I purched this 10-20 as a none running barn find. Got it running and drove it around the yard ran good. Parked near shed and went in for lunch. came out to start and #3 was water locked. PO had machined and ported head for over size valves I think for "pulling". Valve seats cut into water jacket.
I had the head fixed and tested no leaks. When I removed head, the gasket was siliconed on both sides. Found 6 or so head studs with poor threads, so I sealed and replaced them. When torquing 2 or 3 studs do not hold in block. I am now thinking PO broke studs in block and did poor job retaping.
What would you guys do????? oldiron29

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The holes in the head for the studs are larger than necessary, you can retap for one size bigger and they will fit through the head.

(quoted from post at 18:34:19 11/22/11)

(quoted from post at 04:54:37 11/22/11) I saw the post from Ben about the H head stud oops! I have posted this some time ago, and than pushed the 10-20 to the back corner of the shed.
I have never come up with a good method for a fix. I purched this 10-20 as a none running barn find. Got it running and drove it around the yard ran good. Parked near shed and went in for lunch. came out to start and #3 was water locked. PO had machined and ported head for over size valves I think for "pulling". Valve seats cut into water jacket.
I had the head fixed and tested no leaks. When I removed head, the gasket was siliconed on both sides. Found 6 or so head studs with poor threads, so I sealed and replaced them. When torquing 2 or 3 studs do not hold in block. I am now thinking PO broke studs in block and did poor job retaping.
What would you guys do????? oldiron29

Click to expand...

The holes in the head for the studs are larger than necessary, you can retap for one size bigger and they will fit through the head.

Click to expand...

tried that way once. not to favorable, i wont do it that way again