Head stud repair with insert...Q

[hardtimes]

When buying an insert used to repair a 7/16 x 14 head stud (A/B head stud),
what LENGTH insert is needed for best repair ?

I see inserts of .600" and 1" available. Which have you used .
I can't locate any other length, say 3/4" ?

What is your experience/advice ?

[alexiskai]

I don't have personal experience, but the .6 kit will give sufficient sq. inches of thread to work.

[hardtimes]

Originally Posted by alexiskai

I don't have personal experience, but the .6 kit will give sufficient sq. inches of thread to work.

Hey Alex,
'sufficient'.... does not settle my nerves, when talking 55 lbs torque on that stud ?

[alexiskai]

The normal rule, in cases where both the stud and the insert are made of steel, is that the thread engagement should be at least as long as the stud is wide, i.e. 7/16 or about 1/2". A 0.6" insert satisfies that and should handle 55 ft-lbs easily. Time-Sert has an FAQ on their site that mentions a few pointers when installing into blind holes.

Although the insert's threading won't be as long as the threading on the original block, the insert is made of stronger material, so less is needed.

[Pete]

While .600 calculates ok, I would use the long ones. The integrity of the deck material is not new which is what calculations are based on.

My home made tapered inserts are .750 long, for what it is worth.

[alexiskai]

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Only issue with the long ones is you’d have to drill the hole quite a bit longer – maybe into the water jacket.

[Pete]

Originally Posted by alexiskai

Only issue with the long ones is you’d have to drill the hole quite a bit longer – maybe into the water jacket.

Some will go into the water. No big deal if the studs are installed properly. That has been covered many times here.

[Bruce of MN]

The insert I used https://www.mcmaster.com/90259A154/ has a 9/16” length. (The ID should be checked.)

[hardtimes]

Originally Posted by Pete

While .600 calculates ok, I would use the long ones. The integrity of the deck material is not new which is what calculations are based on.

My home made tapered inserts are .750 long, for what it is worth.

'HOME MADE'...what ?
Yeah, Pete .750 is what I"M searching for, but can't locate.
As said the 1" is 'IFFY' long. I've measured depth of stud holes and 1" MIGHT MAKE IT, where .750 would be great.
Any clue of a source ?

Ok, how do you make an insert. Maybe an amateur can do this ??

BTW...this is a 1937 B block that I working. I am finding that the castings seem to be thicker than any , say, 1932 B block that I've seen.
That includes the depth of the STUD holes. I'm close to 1" and no bottom thru yet !
And, I've not seem a B block without the bottoms...of at least some holes knocked thru....except this block !!

[Pete]

Originally Posted by hardtimes

'HOME MADE'...what ?
Yeah, Pete .750 is what I"M searching for, but can't locate.
As said the 1" is 'IFFY' long. I've measured depth of stud holes and 1" MIGHT MAKE IT, where .750 would be great.
Any clue of a source ?

Ok, how do you make an insert. Maybe an amateur can do this ??

BTW...this is a 1937 B block that I working. I am finding that the castings seem to be thicker than any , say, 1932 B block that I've seen.
That includes the depth of the STUD holes. I'm close to 1" and no bottom thru yet !
And, I've not seem a B block without the bottoms...of at least some holes knocked thru....except this block !!

You need a lathe. Inserts are made from 4130 bar stock. Turn the OD and thread it with a 3/8 tapered pipe thread. Do this with a single point tool and taper attachment. (NOT A DIE) Drill a tap size hole in the bar and run a class 3 tap in the hole. Part the piece off.
Take a piece of 1 inch bar stock, put in lathe and drill and tap a 3/8 tapered pipe thread in one end. Use the insertion tool to screw the insert in the hole. Now machine one thread away from the top of the insert. Deburr the corners and it is done.

The insertion tool is made from bar stock. Turn and thread one end to 3/8 STRAIGHT pipe thread. Mill 2 flats on the side of the tool for a wrench. Make a nut to fit the thread. This will be a jam nut.
To install the insert, screw it on the insert tool and tighten the jam nut to the insert. Goop the insert with Loctite green and screw the insert in. It should be "snug". If you need a torque reading, try 15 ft. lb.. Loosen the jam nut. Back the tool out. Let sit over night before using.

Hone the cylinders slightly before assembling to assure none of the inserts pushed the cylinder walls out when installing.

These inserts will stand 100 ft. lb. of torque with a test tool. I never tried to pull one out with a destruction test.

Not needed for a street engine but definitely on a top fuel eliminator engine.

You asked though.....LOL

[hardtimes]

Hey Pete,
Yeah..... I did ask. lol
I didn't expect anything less... that was informative, indeed !
You said GREEN loctite ? The sales ad with insert says RED loctite ?
What brand of ‘mill’ do you recommend ?
I like oatMILL.
Wish Ida paid attn in metal class, eh !!

[Ruth]

Could you use an oversize stud and forget the insert? That would be my first choice.

[Pete]

Originally Posted by hardtimes

Hey Pete,
Yeah..... I did ask. lol
I didn't expect anything less... that was informative, indeed !
You said GREEN loctite ? The sales ad with insert says RED loctite ?
What brand of ‘mill’ do you recommend ?
I like oatMILL.
Wish Ida paid attn in metal class, eh !!

Ah, green, red, pick a color. In the old dayz before they knew about anerobic gloo, we used shellac.

As for a mill, the more you pay, the better it is. A Bridgeport is probably at the bottom of the scale but it will work for anything that will fit on the table.
I like Pratt & Whitney because of the quality and they made lots of other neat stuff also.

As far as metal class, there are plenty of those available nowdays at trade schools and they are FAR better than the ones we had.

[Pete]

Originally Posted by Ruth

Could you use an oversize stud and forget the insert? That would be my first choice.

Yes, but I would check the new stud with a test pull at about 20% above what you are going to run it at.

[Ruth]

Originally Posted by Pete

Yes, but I would check the new stud with a test pull at about 20% above what you are going to run it at.

Well the oversize studs Bratton's has are Grade 8. And you're installing it in the same block as an insert. So I would think it goes to say you would have to test pull your insert as well.

[Pete]

Originally Posted by Ruth

Well the oversize studs Bratton's has are Grade 8. And your installing it in the same block as an insert.

The stud is not the worry. It is PLENTY strong.
The ancient metal near the block hole is the problem.

[hardtimes]

Originally Posted by alexiskai

The normal rule, in cases where both the stud and the insert are made of steel, is that the thread engagement should be at least as long as the stud is wide, i.e. 7/16 or about 1/2". A 0.6" insert satisfies that and should handle 55 ft-lbs easily. Time-Sert has an FAQ on their site that mentions a few pointers when installing into blind holes.

Although the insert's threading won't be as long as the threading on the original block, the insert is made of stronger material, so less is needed.

Hey alex,
Very helpful info !
Ill follow up with that site. Thanks

[hardtimes]

Originally Posted by alexiskai

The normal rule, in cases where both the stud and the insert are made of steel, is that the thread engagement should be at least as long as the stud is wide, i.e. 7/16 or about 1/2". A 0.6" insert satisfies that and should handle 55 ft-lbs easily. Time-Sert has an FAQ on their site that mentions a few pointers when installing into blind holes.

Although the insert's threading won't be as long as the threading on the original block, the insert is made of stronger material, so less is needed.

Hey alex,
Very helpful info !
Ill follow up with that site. Thanks

[hardtimes]

Originally Posted by Ruth

Could you use an oversize stud and forget the insert? That would be my first choice.

Hey Ruth,
Someone else mentioned oversize studs and Brattons. I’ll check that. Brattons is the one catalogue... I don’t have.

That being said, my stud hole problem is more than a few thou oversize stud will fix.
Thanks.

[john charlton]

You say your B block deck seems thicker than normal . English Dagenham blocks have a thicker deck by about 1/16" to avoid cracking which the Detroit blocks suffer from . Does it have any casting marks on it such as"GS" and a date .Some do some dont . The Dagenham block is very robust and not prone to cracking . The rear main setup is also different . Returning USA service men brought English cars into USA the "B" engine retro fit was common .

John in Suffolk County England .

[Jack Shaft]

Torque is used to put the stud in tension. This allows the assembly to be made without a locking device and provides a stable basis for heat cycling. In my experience .6 is an adequate depth of threads for a 7/16th NC stud.

Use a magnetic base drill (rent one) to insure the pilot hole for the insert is square to the deck. Drilling by hand can result in an offset pilot hole, placing two forces on the stud when tensioned. I prefer the integrity of a timesert and use anaerobic sealant on installation (loctite). Anaerobic means in the absence of air it cures, given the weakness and ductility of ford grey iron castings the sealant actually helps support the assembly by filling any void as well as locking it.

[hardtimes]

Originally Posted by Jack Shaft

Torque is used to put the stud in tension. This allows the assembly to be made without a locking device and provides a stable basis for heat cycling. In my experience .6 is an adequate depth of threads for a 7/16th NC stud.

Use a magnetic base drill (rent one) to insure the pilot hole for the insert is square to the deck. Drilling by hand can result in an offset pilot hole, placing two forces on the stud when tensioned. I prefer the integrity of a timesert and use anaerobic sealant on installation (loctite). Anaerobic means in the absence of air it cures, given the weakness and ductility of ford grey iron castings the sealant actually helps support the assembly by filling any void as well as locking it.

Hey Jack,
Thanks for your input !
Very helpful. I’ll check on timesert for comparative detail with others I’ve studied.
Don’t know of magnetic base drill. Sounds good idea.
I am terrible at drilling straight. With shakes and arithritis hands, that aint happening. That wont keep me from trying.

BTW - Im familiar with ‘anaerobic’ .. sealant. But why not just use 2 part epoxy of some sort ? Especially , if hru to water ?

[Richard Knight]

Hardtimes, To get your holes straight just use a cylinder head. Mark the holes you want to drill out for inserts on the head with chalk, I used heli-coils, and use the proper drill for the insert. Use three or four studs to hold the head on and drill away. works every time. Rick.

[Ruth]

Originally Posted by hardtimes

Hey Ruth,
Someone else mentioned oversize studs and Brattons. I’ll check that. Brattons is the one catalogue... I don’t have.

That being said, my stud hole problem is more than a few thou oversize stud will fix.
Thanks.

The oversize stud is more than "a few thou oversize". The threads that go into the block go from 7/16"-14 to 1/2"-13 for the oversize stud.

https://www.brattons.com/over-size-t...long-stud.html