5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

onebighead

Petty Officer 3rd Class
Joined
Oct 21, 2008
Messages
78
Re: 5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

Today I installed one helicoil in the starter bolt hole. I stepped up the drill size one at a time until I got to 25/64. It seems I got a good, straight hole, tapped it, installed helicoil, and so far, so good. It torqued, and that is good. I need a little luck here and there on this boat.
thanks for all the input......not finished on this boat yet.
 

tinkerguy70

Petty Officer 2nd Class
Joined
Oct 12, 2012
Messages
190
Re: 5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

Today I installed one helicoil in the starter bolt hole. I stepped up the drill size one at a time until I got to 25/64. It seems I got a good, straight hole, tapped it, installed helicoil, and so far, so good. It torqued, and that is good. I need a little luck here and there on this boat.
thanks for all the input......not finished on this boat yet.

Well good. I'm glad it's working for you.
Just a note: I always put a drop of blue locktite on the helicoil when I install it.
That helps to keep it from backing out with the bolt whenever you have to remove it.
Just a suggestion, some kits come with it and some don't. Your mileage may vary. ;)
 

Ridewright79

Seaman Apprentice
Joined
Jan 2, 2013
Messages
46
Re: 5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

It maybe late but wanted to add this.
See if you can get your hands on some keen inserts. They are basically like a helicoil but more of a sleeve instead of just threads. A lot of engine manufactures use them to put threads into blocks for head gaskets. Not cheap but will hold better than anything else on the market. Our dealership uses them to repair blocks, heads, and everything else. Just thought I would suggest it.
 
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etracer68

Ensign
Joined
Oct 11, 2009
Messages
906
Re: 5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

The starter bolt holes that I have seen on chevy blocks, have a counter bore in them. This is to aline the starter bolt, and the knerl is to aline the starter. The front of the bolt body needs to engage. Correct starter bolts are a must. As long as you dont drill out that counter bore, you should be good to go. I would think going to the larger size drill, for the helicoil, you may enlarge that counter bore.
 

onebighead

Petty Officer 3rd Class
Joined
Oct 21, 2008
Messages
78
Re: 5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

etracer68 and others, thanks for your comments. etracer68, I'm not sure what you mean by counter bore. I do have the correct starter bolts, but I drilled all the way through the hole to the top. Then I inserted the helicoil at a distance to engage the bolt threads completely. As I mentioned in a previous post, a little luck is always needed. thanks
 

etracer68

Ensign
Joined
Oct 11, 2009
Messages
906
Re: 5.0 mercruiser chevy starter bolt holes stripped, helicoil or not

The counter bore is a area that is before the thread starts. About 1/4 deep from the suface the starter mates to. Its a bit larger then the outside diameter of the threads. The threads dont start at the surface, they start about 1/4" in.
 
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