Stripped smallblock timing cover bolt

[JMcTurnan]

I have a stripped timing cover bolt hole, I was going to put a helicoil in it. Any idea what the size is? It's a smallblock

[cep62]

Get a set of open end wrenches.
1/4 ,5/16, 3/8, 7/16 ,1/2.
Those will give a good guess at the diameter.
Get a good tap and die set , that should have a thread gauge to get the pitch.
1/4 20 or 28, 5/16 18 or24 ,3/8 16 or24 ,7/16 14 or 20 , 1/2 13 or 20 etc

[JMcTurnan]

Whats the pitch?

[OldRedFord]

Thread pitch-

The distance from one thread groove to the next, measured from crest to crest.

I would just tap it out to the next size, if it was me.

[JMcTurnan]

http://www.harborfreight.com/cpi/ctaf/d ... mber=39391

This tap and die set, what is the second number after the diameter of the hole.
What are those round things? Ive never used a tap and die, or helicoil. None of that stuff.

[OldRedFord]

TPI or threads per inch. 1/4 20 would be a 1/4 inch thread with 20 threads per inch.
Im not sure I owuld get a HorribleFreight tap & die set.

The round things are dies, for threading a bolt, or stud.

[JMcTurnan]

Oh that actually matter =0, we always called them normal threads or metric threads LOL, cause it seemed that metric ones had more TPI. Pardon my redneck automotive maintnence .

[JMcTurnan]

Anyone give me a quick knowledge buster of how to use ones, I just wrapped copper wire around the bolt to help it thread LOL.

[JMcTurnan]

Oh that die threads bolts? Or studs?

[cep62]

Those round thing are the dies made for threading the bolt.
The tap is made for threading the nut or the hole.

You have to be careful because they break easy, so just go a quarter turn then back it up.
and use plenty of oil .
Because you haven't lived until you try to get a broken tap out of a blind hole.

[JMcTurnan]

So I still don't get to tap it, will the tap i buy tell me a certain size bit to drill it out with?

[cep62]

Oh that actually matter =0, we always called them normal threads or metric threads LOL, cause it seemed that metric ones had more TPI. Pardon my redneck automotive maintnence .

Well there's normal (also called sae or standard) coarse and fine tread.
And there's Metric coarse and fine thread.
In fact 10mm , and 12mm have 3 different pitches.

[ToughOldFord]

So I still don't get to tap it, will the tap i buy tell me a certain size bit to drill it out with?

It should.

[OldRedFord]

Oh that die threads bolts? Or studs?

Yup, both.

So I still don't get to tap it, will the tap i buy tell me a certain size bit to drill it out with?

Sometimes it will.

For example, my 5/8 tap I bought says to use with a 17/32 drill bit.

Here is a handy dandy chart I found. Lists metric and standard tap sizes, and drill bit size for each.

http://www.korit.com/tapndrill.htm

[ToughOldFord]

A quick google will give you some how to's and you tube even has some videos:

http://www.wikihow.com/Use-a-Tap

http://en.wikipedia.org/wiki/Tap_and_die