Problem with chasing heald bolt holes.
Thread Starter
Senior Member since 1492
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From: Just because I'm paranoid doesn't mean people aren't out to get me...
St. Jude Donor '09
Problem with chasing heald bolt holes.
I started slowly chasing the holes in my block. I was almost done with one side when the chase stops, almost all the way thru. Now I stuck a straw thru the hole so I know it's hollow. Are all the 454 head bolt holes hollow?
This one must have some serious corrosion or built up sealant in it. Should I apply enough force(rachet) to screw the chase thru?
This one must have some serious corrosion or built up sealant in it. Should I apply enough force(rachet) to screw the chase thru?
Race Director
Joined: Mar 2001
Posts: 11,322
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From: Living in the Hartland
Re: Problem with chasing heald bolt holes. (1970 Stingray)
It might not have been threaded all the way through. I would back it out and inspect a little closer before trying to force it through. I have had some thread chasers snap which is no fun. Try a bolt with some oil instead.
Le Mans Master
Joined: Mar 1999
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From: delmont pa
Cruise-In I Veteran
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Re: Problem with chasing heald bolt holes. (1970 Stingray)
they all go thru to the water jacket but some of the botttom row have casting flash and the tap will not go clear thru. never use aftermarket head bolts that are longer than stock because they will bottom out in these holes and cause the head gasket to blow. been there done that when the BB came out in the 60s. :chevy
[Modified by clem zahrobsky, 11:46 AM 7/2/2002]
[Modified by clem zahrobsky, 11:46 AM 7/2/2002]
Melting Slicks
Joined: Apr 2000
Posts: 3,286
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From: San Jose California
Re: Problem with chasing heald bolt holes. (1970 Stingray)
If this is a threaded hole open to the water pockets below, it shouldn't be tapped all the way through. That's why you use a good sealant on head bolts, many access the water pockets.
Chuck
Chuck
Burning Brakes
Joined: Apr 2001
Posts: 752
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From: Springfield Oregon
Re: Problem with chasing heald bolt holes. (1970 Stingray)
Triple check your tap size. I was cleaning out the threads on the deck of my 350 when I had a similar hangup about halfway through one side. Turned out I had accidentally grabbed the 7/16fine instead of the 7/16course. Ended up getting a good lesson in helicoil repair. Doubt this is you problem, but worth a check.
Thread Starter
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From: Just because I'm paranoid doesn't mean people aren't out to get me...
St. Jude Donor '09
Re: Problem with chasing heald bolt holes. (Chuck Harmon)
Thanks for the replies guys.
All the holes on the one side, except this one, go thru to the water jacket. I'm using the same thread chaser, so there was no chance of a mix up there. This last one has, I'd say maybe two threads left to clear before I enter the jacket. ALL the bolt holes in this BB are hollow. I stuck a straw thru each one just to check. I'll leave the threads "as is" for now.
Clem, when I bought the GMPP heads they recommended a specific head bolt set which I plan to use.
Thanks again.
Len
All the holes on the one side, except this one, go thru to the water jacket. I'm using the same thread chaser, so there was no chance of a mix up there. This last one has, I'd say maybe two threads left to clear before I enter the jacket. ALL the bolt holes in this BB are hollow. I stuck a straw thru each one just to check. I'll leave the threads "as is" for now.
Clem, when I bought the GMPP heads they recommended a specific head bolt set which I plan to use.
Thanks again.
Len
