head bolt help

[ksurfer2]

One of the bolt holes in my block (440) is stripped (one of the long ones in the middle). A couple of questions, can this be helicoiled, what size/pitch helical do I need. And most important, does the bolt hole go all the way through to the crank case, or is there a bottom to the hole? I don't want to push any metal shavings into the pan. I have masked off the top of the block in prep for drilling.

 

[pnora]

Should be a blind hole. Easy to check. Fill it with brake clean. Thread should be 7/16-14

 

[zyzzyx]

Make sure that you go to Helicoil site and check how long of an insert you need for that particular
torque value! You can't just stick a short one in and go with it, especially in cast iron and aluminum.
It'll last forever.

 

[tubalcain]

It might be good to consider a jig with a drill bushing to insure a vertical hole. Hand drilling is not that accurate. You might do fine with a hand drill but what if it's off a bit too much?

 

[Virg464]

If the heads off, you might try to find a mag drill to keep everything straight (like "tubalcain" mentioned).

 

[pnora]

It might be good to consider a jig with a drill bushing to insure a vertical hole. Hand drilling is not that accurate. You might do fine with a hand drill but what if it's off a bit too much?

The hole is already there. All he is going to do is size it and retread it for the heli-coil. No reason to overthink a simple project.

 

[fourgearsavoy]

I suggest using a Timesert instead of Helicoil.

Gus

 

[tubalcain]

The hole is already there. All he is going to do is size it and retread it for the heli-coil. No reason to overthink a simple project.

Yes, blocks are replaceable Afterall, so why not just git'er done and risk it?

 

[pnora]

Yes, blocks are replaceable Afterall, so why not just git'er done and risk it?

I guess you have never done one.

 

[Orig69]

One of the bolt holes in my block (440) is stripped (one of the long ones in the middle). A couple of questions, can this be helicoiled, what size/pitch helical do I need. And most important, does the bolt hole go all the way through to the crank case, or is there a bottom to the hole? I don't want to push any metal shavings into the pan. I have masked off the top of the block in prep for drilling.

Do you have pictures of the cylinder head bolt that was in the stripped hole?

 

[Geoff 2]

The thread should be deeper than the thread engagement of the bolt. A stud that goes to the bottom of the unused thread with high strength Loctite might get you out of trouble. Worth checking out.....

 

[Doorkicker]

I'd recommend... after you put in the helicoil (preferred) or timesert, I'd consider using a stud as opposed to a bolt moving forward. It puts less wear and tear on the insert when removing and installing heads in the future. The hole is blind (does not go into the water jacket) and the bolt is 7/16-14, 3.875 in long. Remove the head and measure the depth of the hole before doing anything. Be especially sure not to drill & tap the hole any deeper than it is or farther than the current bolt goes into the hole. Helicoils include installed length.. so triple measure the depth again after drilling and tapping. Also, helicoil does make tangless coils... something to consider to save you from having to get the tang out after installing. Consider using loctite on the helicoil...technically not necessary, but once in... you never want out.
Anyway, good luck - take your time.

 

[zyzzyx]

The 7/16-14 inserts come in lengths of one times the diameter, 1185-7CN438, which in my opinion is not long enough for
90Lb/Ft. They also come 1-1/2 X diameter, 1185-7CN656, and 2 X the diameter, 1185-7CN875. I would use the longest
insert if the hole is deep enough, and yes, I would borrow or rent a mag base drill to insure the hole is perpendicular to
the top of the block. Make sure you chamfer the hole!

 

[pnora]

 

[JC Boatguy]

I suggest using a Timesert instead of Helicoil.

Gus

Timeserts RULE!!!

 

[65CopCar]

It might be good to consider a jig with a drill bushing to insure a vertical hole. Hand drilling is not that accurate. You might do fine with a hand drill but what if it's off a bit too much?

Totally agree. If you have access to a mill not hard to make. I would be using a hard drill bushing. No need for a mag drill if use a jig like this.

I think you would be fine with either an insert or a helicoil.

 

[Krooser]

So sad to think some here would spend huge $$$'s to replace an engine block over a $30 repair.

 

[Bryan Lohmiller]

Yes use a Timesert as several others have said

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www.timesert.com

 

[Orig69]

The original cylinder head bolt only goes approx 5 threads into the engine block which leaves at least 12 more threads for a cylinder head stud.

 

[PRHeads]

Any updates?