SAVE A THREAD trick ?

[crosbyman]

while prepping my 4w71 4hp for winter I found my top plug barely holding on a few threads which quickly stripped when installing the top plug.
cyl head # 314779

No fear I had a SAVE- A -THREAD kit ready with the proprer inserts. 😀

Unfortunately….. the cyl head plug sockets are not perpendicular (slated about 20 deg. )and the tool tip hits the inner side wall making it impossible to rethread the damage area for the new insert 🙁

Any tricks anyone ? should I just buy myself a regular (short) die sized for the insert’s outer thread size ?

thanks

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[frankr]

I don’t understand. Am I not reading the problem correctly? But of course it is a job for a drill press or milling machine to hold the head at the proper angle as the tap goes straight into the hole.

[crosbyman]

the save a thread tool tip has cleaning threads followed after with a tappered section leading to a bigger die size to cut new oversized threads into which to screw the insert.

with the plug holes slanted on these cyl heads the first section of the save-a thread tool hits the back wall facing the plug holes making it impossible to uset the oversize cutting section of the cutting dye .

Joining AOMCI has priviledges 🙂

[wedgie]

The simplest and most logical solution ? Find yourself another cylinder cover. Where are you located Crosbyman?

[joecb]

use a heli-coil. Of course you will have to invest in a new special tap.

Joe B

[frankr]

quote crosbyman:

the save a thread tool tip has cleaning threads followed after with a tappered section leading to a bigger die size to cut new oversized threads into which to screw the insert.

with the plug holes slanted on these cyl heads the first section of the save-a thread tool hits the back wall facing the plug holes making it impossible to uset the oversize cutting section of the cutting dye .

.Oh, ok I think I can visualize what you are saying now. Sounds like time for a new head.

EDIT: Oops, looks like they are NLA.

[mr-asa]

Try cutting from the other side?

[wedgie]

I thought I had one, but can’t seem to find it. Here’s one on the Bay. There is a NOS one on there too for $27.50 and Seaway has new ones for $75.00 😮

http://www.ebay.ca/itm/like/27192390460 … rmvSB=true

[crosbyman]

I am in Montreal Canada

Heli coil and "save a thread" are basically the same kind of tool ( tap and inserts). it wont work from the inner face of the cyl head either .. not enough space .

IF I buy a tap for the insert what size and thread should I buy although a tap that size may be as expensive as a used cyl head.

I’ll post on webertize for a cyl head ( EBay folks wont ship to Canada most of the time !)

I need to check a local shop… maybe they can tap for me.

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[billw]

I always thought the cleaning part of those taps was some kind of gimmicky thing. Good, larger taps can be kind of pricey. I would consider grinding off the cleaning part of the special tap. Then use a proper size drill to clean out the old threads, like Heli-coils use? If that goes against your better judgement, you can measure the pitch and diameter of the threads, if you have a tap and die set. Just keep in mind that even the outer thread of the insert may be metric, seeing as the inner part is 14 mm. It might even be a special thread, but I kind of doubt it.

Of course, another head is a lot easier; but where is the challenge in THAT? 😀

Long live American manufacturing!

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