Helicoils....who is our best guru?

[Jon Tilson]

I've never fitted a helicoil myself.

I have a stripped thread in the block for a water pump cover bolt on a sprint engine. Its already been drilled and tapped out to the next unf size
up, but sadly that has now gone too.

Any info on suppliers etc would be gratefully received.

Jonners

[cliftyhanger]

Not a guru, but used them a few times. I borrowed a spark plug one for our MX5. And bought one when I needed it from a local supplier, unbranded or maybe sealey?

Nothing complicated with them, I would probably buy from fleabay if no rush.

[tinweevil]

Namrick do equivalents cheaper than a genuine helicoil, I've 3 sets covering the usual UNC sizes and have used them with 100% success. Never needed to do one in iron so good luck.

[Jon Tilson]

Thanks lads...

Looks like I need an M8 or 5/16 unf to do the job...

Any other info gratefuly received.

Jonners

[tinweevil]

None of the sets I've seen include the drill bit you'll need. Ask when you buy for the right size.

[MIG Wielder]

Thanks lads...

Looks like I need an M8 or 5/16 unf to do the job...

Any other info gratefuly received.

Jonners

Hi Jon, I can do you an M8 x 1.25 helicoil set. There are 5 inserts left. The drill looks like 8.3mm which I must have as well. Are you still working at " that place "? Do you need it for this w/e for instance ? If you go through Camberley on the A30 there is A.H.C. Ltd who do a vast range of generic Helicoil kits.
Cheers for now,
Tony.

[tony g]

If its already been tapped to the next unf size which would be 3/8 I doubt a helicoil for 5/16 or 8mm will do the job as too much material has been taken already. If the hole can be drilled bigger you can use an insert called a "key sert" which has a much larger O/D but with the desired I/D. I'll see if I can find a link for them.


here is some info: http://www.newmantools.com/key.htm#cs


Tony

[tarynus]

I got some of the taps i needed from this website and lots of info about sizes
http://www.baercoil.com/shop/catalog/#
You can probably find something in the uk, quicker and less postage but it might come in handy.

[MIG Wielder]

If its already been tapped to the next unf size which would be 3/8 I doubt a helicoil for 5/16 or 8mm will do the job as too much material has been taken already. If the hole can be drilled bigger you can use an insert called a "key sert" which has a much larger O/D but with the desired I/D. I'll see if I can find a link for them.

Tony

Ah ! I see the problem . Tes, M8 is going to be too small. If the original bolt was 5/16 UNF-24 with a 1/2 in AF hex, the next size up is 3/8 -24 UNF with a 9/16 hex ( as Tony has noted. I measured a 3/8 -24UNF bolt and the O.D. is 0.368 in or 9.35mm which will be the diameter of the hole in the block now.
M8 helicoil needs an 8.3 mm drill ( too small) .
So the obvious choice would be a 3/8 UNF helicoil ( 9.8mm drill ).
There is an M9 helicoil (9.4mm )drill but its an odd size.
If you have 3/8 UNC helicoil kit that needs a 9.9mm drill, but its a coarse thread and you wouldn't get too many turns into blind hole.
It might be a case of getting the 3/8UNF Helicoil kit.

[Jon Tilson]

Thanks for the info guys.

In the end I went with the 3/8 unf helicoil. The kit was kindly loaned by Tony.

This was a useful site for key inserts and info....

http://hyquip.carrlane.com/catalog/inde ... 2853564755

Jonners