cylinder head spark plug hole threads stripped in LB model 10323

blowerhead said:
After 19 seasons, The threads in the spark plug hole are stripped. Other than getting another head, any suggestions?
Thanks
Click to expand...

I cross threaded one and I got a special tap for spark plug holes...different size each end.
I rethreaded with the tap and put my plug back in.

I don't know if you could put something like a serviceable locktite on the threads to help seal it if that would affect grounding of the spark plug.
 
shiftsuper175607 said:
I cross threaded one and I got a special tap for spark plug holes...different size each end.
I rethreaded with the tap and put my plug back in.

I don't know if you could put something like a serviceable locktite on the threads to help seal it if that would affect grounding of the spark plug.
Click to expand...

Loctite should never ever be used on a spark plug.
At running temperatures it will be soft and when cold it will be at full strength making replacing the plug very difficult.
you would then have to clean out the threads and reapply.
There is a product available that will do the job but it is very expensive and not easy to get, for very good reasons.
 
bertsmobile1 said:
Loctite should never ever be used on a spark plug.
At running temperatures it will be soft and when cold it will be at full strength making replacing the plug very difficult.
you would then have to clean out the threads and reapply.
There is a product available that will do the job but it is very expensive and not easy to get, for very good reasons.
Click to expand...

I said serviceable Loctite...which can allow removal
The point is...the head is bad and this might allow a temporary fix for continued use.
spark plugs are not removed very often on a good running machine.
 
reynoldston said:
Very bad idea anti sieze, don't cross thread the new plug and use a torque wrench if you have one when you install. You should be able to install the new plug with just your fingers and then just tighten to specs. There is a reason the new plug striped out the head. I would price out a used or new head before buying a Heli coil set it might just be cheaper. You will need a complete kit for just one plug, not worth the cost.
Click to expand...

Totally wrong.
You should not use anti sieze on plugs going into a normal plug hole
However Helicoils are stainless and time serts are high nickel .
Both of these alloys will gall & sieze when used against a high nickel spark plug.
The makers of the inserts recommend using the high temp anti sieze (not the low temp copper one ).
As do car makers on alloy headed engines with inserts fitted from new, you know people with no idea about engineering like Rolls Royce, Ferrari, Jensen, Healey.
Contry to popular belief a spark plug can ground perfectly well using the base & washer ( where fitted ) against the head, it does not need the thread to make a ground contact
 
Just my two cents, have installed more spark plug HeliCoils as well as bolt HeliCoils than I care to count, never had one return to bite me. One thing I do is use sleeve lock on each one and it must sit for 12 hours before a plug or bolt is put in them.
 
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