Head stud pattern?

[JayJay]

Does anyone have a dimensioned drawing of the head bolt pattern (X-Y)? I've broken a head stud and need to make up a jig to drill out the broken stud. I could make up a jig based upon the head or head gasket, but if I could find a properly dimensioned drawing it would be a lot easier. And likely more accurate.

I know there are commercial jigs out there but that takes time. And dollars for a special purpose tool I likely will never use again (I hope!). I have some stock I can repurpose.

Thanks.

JayJay

[BRENT in 10-uh-C]

Originally Posted by JayJay

Does anyone have a dimensioned drawing of the head bolt pattern (X-Y)? I've broken a head stud and need to make up a jig to drill out the broken stud. I could make up a jig based upon the head or head gasket, but if I could find a properly dimensioned drawing it would be a lot easier. And likely more accurate.

I know there are commercial jigs out there but that takes time. And dollars for a special purpose tool I likely will never use again (I hope!). I have some stock I can repurpose.

Thanks.

JayJay

I think I do. I plotted this out a long time ago so my memory is struggling to remember if I modified it in any way during machining. I am assuming you have a DRO to use for coordinate locations?

One other thought, if you have access to a lathe, then machine yourself a sleeve to slightly press inside of a head stud hole that has the ID for a ¼" drill bit to use as your pilot. Install the cylinder head onto the block using several head studs for positioning and then drill your ¼" pilot hole in the broken stud. One drilled, remove the head and using a left-hand drill bit, set up on a Bridgeport (-or drill press) try pecking the broken stud with the left-hand drill bit to back it out. Usually works very well.

.

[J Franklin]

A machine shop can burn out the stud remains electronically. It is an option.

[JayJay]

Thanks, Brett and JFranklin. Block is still in the car so I'm somewhat limited in what I can do.

No, Brett, I don't have a DRO. If I make the jig I was going to set up the jig on my mill using old fashioned dial indicators on the X-Y axis (taking account for backlash, of course). I already thought about making bushings and using the head, great minds think alike. I'll try that first.

Not sure a left hand drill will work, all the head studs were in pretty tight and they were all mega-crusty with rust (this one broke off right at the top of the block, it was visibly narrower there with rust. Nothing protruding so I couldn't weld a nut on.). And I have to use a hand drill anyhow as the block is still in the car (over the years I've had mixed success with left hand drills even when using a drill press or mill). I was going to try to get close to pilot hole size and then pick out the bolt remains from the block. All else fails I may have to use a Heli-coil or an oversize head stud (Bratton's has them).

JayJay

[nkaminar]

A drill and sleeve came with my car that is used in the hole in the head and I think there is an Eazyout with it too. I don't know where you can buy one but it has to be available somewhere. The backwards drilling drills are good to use in drilling out a stud because it will not tighten the stud and may take the stud out if it catches.

[BRENT in 10-uh-C]

Sponsored Links (Register now to hide all advertisements)

Originally Posted by JayJay

Thanks, Brett and JFranklin. Block is still in the car so I'm somewhat limited in what I can do.

No, Brett, I don't have a DRO. If I make the jig I was going to set up the jig on my mill using old fashioned dial indicators on the X-Y axis (taking account for backlash, of course). I already thought about making bushings and using the head, great minds think alike. I'll try that first.

Not sure a left hand drill will work, all the head studs were in pretty tight and they were all mega-crusty with rust (this one broke off right at the top of the block, it was visibly narrower there with rust. Nothing protruding so I couldn't weld a nut on.). And I have to use a hand drill anyhow as the block is still in the car (over the years I've had mixed success with left hand drills even when using a drill press or mill). I was going to try to get close to pilot hole size and then pick out the bolt remains from the block. All else fails I may have to use a Heli-coil or an oversize head stud (Bratton's has them).

JayJay

DROs have definitely made us lazy (-or at least less of a machinist!! ) but it definitely can be done that way. Based on the fact that the engine is still in the chassis, and that you only have a hand drill, I would use the head with a sleeve as your guide to drill the stud in the center all the way through.

[GeneBob]

For what it is worth; I drilled out the threads in my block and heli-coiled them. I installed ARP studs/washers/nuts. However, the point is, I made a drill guide block to keep my drilling straight for drilling out the block and it worked well. I was only drilling out the original threads so I didn't need much. I think you should have good success using the approach Brent suggested; even with a hand drill, if you take your time. And going to heli-coils is not difficult so don't be afraid of that step. The length of the standard heli-coils for the 7/16 coarse thread is about 5/8" and fits perfectly.
A shop vac comes in very handy to keep the chips from getting into places you don't want them.

[Benson]

wHY NOT TRY THIS MIG welder (Washer Nut) method

I have seen it done a number of times.

If it does not work you have not lost anything.

Dealer solution to my problem was replace $2000 intermediate pipe with CAT, Mufller and tail pipe.

15 minutes and a Mig welder and it was fixed.

Two studs and gasket and done.

https://www.youtube.com/watch?v=PQ0YkPb3oVs

[Y-Blockhead]

Snyder's has a jig that might fit your needs. https://www.snydersantiqueauto.com/p...8656&cat=41753 I have never tried it so no comment on how it works.

Snyder's used to have a bushing that fit in the head stud holes and used the head as your jig. It worked very well for the times I used it but they don't list it anymore.

[JayJay]

I have a lathe, so I made a couple of sleeves to fit in the hole in the head. The hole in the head measured out at 0.461+" diameter by ~2-1/8" deep, and I had some 3/4" round stock that I drilled out and then turned down. I made one sleeve 1/4" bore to use as a pilot drill, and made the second sleeve to fit a size "U" drill, which is the proper tap drill size for the 7/16"-14 threads in the block. My plan is to install the new studs, minus one, and then put the head on and tighten the nuts to stabilize it. Then the small insert and put a pilot hole. Depending on how lucky I feel, I might try to drill with a left-hand drill and see if it will come out, or maybe an Easy-out (I've had spectacular failures with Easy-Outs) but if unsuccessful I'll use the larger insert with the tap drill hole. With some luck I will have hit the exact location and be able to pick out the remains of the bolt in the wall of the hole. Not the way I'd do it if I could clamp to a mill table, but it is what it is.

If totally unsuccessful I'll either go for a HeliCoil or else drill it out again and thread for 1/2" head bolt (Brattons has them).

I'm optimistic I can make it work.

BTW, I found that the holes in the head vary a bit in diameter, which is to be expected in a casting. So if you do this yourself be sure to size your sleeves to the particular hole in question.

Y-B - I saw that Snyders tool - $35 plus tax, shipping and a week. I was slightly tempted, but was able to knock out the sleeves in a couple of hours using stock I had on hand.

Brent, thanks for your input and counsel. I'll report on how successful I am, likely not until next week sometime.

JayJay

[johnneilson]

Here is a layout I use for locations, there are extras but you can figure it out.

John

[1crosscut]

You said that the stud broke off below the top of the block so there was not a way to weld a nut to the broken off stud.
That is not a problem. I've welded a washer and a 3/8" nut to several like that and had good success in getting them out.
I drill a 1/4" hole in the center of the broken off stud about 1/4' to 3/8" deep. I then place a washer centered over the stud and with a little extra stick out with of the mig wire I fill the hole in the stud and fill up the cavity in order to build the weld up to the washer. Once it is filled up to the washer place the 3/8" nut on the washer and fill the center of the nut with weld.
Let it cool completely and then work it back and forth to break the stud loose.

Your weld will not stick (or only very lightly stick) to the cold cast iron block.

No worries if the nut and washer break off from the stud. Sometimes it takes up to a half dozen tries to finally get one out.

It is the heat and cool cycle that is key in this process.

I'd much rather go this route then try to drill one out to the point of picking out the threads from the block.

[rotorwrench]

Welding on a washer and then a nut to the washer works well on the V8 engines through the 8BA era. The weld doesn't like to knit to cast iron.

Some machine shops have the sonic disentigrators but not all.

[JayJay]

Originally Posted by 1crosscut

You said that the stud broke off below the top of the block so there was not a way to weld a nut to the broken off stud.
That is not a problem. I've welded a washer and a 3/8" nut to several like that and had good success in getting them out.
I drill a 1/4" hole in the center of the broken off stud about 1/4' to 3/8" deep. I then place a washer centered over the stud and with a little extra stick out with of the mig wire I fill the hole in the stud and fill up the cavity in order to build the weld up to the washer. Once it is filled up to the washer place the 3/8" nut on the washer and fill the center of the nut with weld.
Let it cool completely and then work it back and forth to break the stud loose.

Your weld will not stick (or only very lightly stick) to the cold cast iron block.

No worries if the nut and washer break off from the stud. Sometimes it takes up to a half dozen tries to finally get one out.

It is the heat and cool cycle that is key in this process.

I'd much rather go this route then try to drill one out to the point of picking out the threads from the block.

I've seen this done but never done it myself. May give this a try, seems logical. Certainly seems on the surface to beat drilling out. Thanks.

JayJay

[Bruce of MN]

My stud wasn't broken, but I did have to install inserts while the motor was in the car: https://www.fordbarn.com/forum/showt...ud#post1997462

[JayJay]

Well, I got it out by welding a washer, then a nut to the stud. Good thing, too, because I tried center drilling to give a bit more to weld to (as 1crosscut suggests) and the stud is harder than my drill. Anyhow, thanks for all the input.

Turns out, someone had the same problem in the past - I found one bolt hole already had an insert in it.

JayJay

[1crosscut]

Well done!
It's good to get a win once in a while.

[nkaminar]

If you add an insert, use an old head as a guide to drill the block for the insert.

[JayJay]

Originally Posted by nkaminar

If you add an insert, use an old head as a guide to drill the block for the insert.

Excellent point. I was at a swap meet last weekend and picked up an old rusty sacrificial head with that in mind. Now I have it in case I ever run into that situation. Took me a good 20 minutes to clean the water jacket of the critter nests... wouldn't want mouse goodies dropping into the block.

JayJay

[Dodge]

The nut welded to the broken off stud has worked well for me.
Just recently I was taking the head studs out of a 1934 Chrysler 8 block. The studs were
the worst I had ever encountered, I tried all my old tricks but nothing was working.
I bought one of those induction heaters with the coil on the end that heats the studs.
It was still tough but all but one came out successfully.
I used the welded nut method with an impact gun and out it came.