Re: Plug problems

["Glenn A. Merrell" <gmerrel@domain.elided>]

Tim Shaw wrote:
> 

> I've discovered to my horror that 3 out of 8 plugs threads are
> stripped. The plugs will go in but I can rock them up and down with my
> fingers. The car runs better than before with the new ignition, and
> all 8 cylinders are firing, but it can't be good having loose plugs?
> Is there any method of securing them without using helicoils which I
> assume will mean removing the heads, at which point I might as well go
> the whole hog and get unleaded valves fitted?


Hello Tim,
	You are correct, it is not good to run for very long with loose plugs. 
With the "loose plugs" high revs will most likely blow one or all out at
THE most inopportune moment.  Helicoils just do not work for long in a
Stag head, they will loosen and blow out.  A quick trip to your local
automotive performance parts supplier will have several manufacturers of
threaded inserts.  These come with a custom tap and hardened steel
threaded insert.  Best way to buy them is in a complete engine kit if
you have 3 loose plugs, one tap, 4 or 8 inserts.
	You are also correct about removing the head to do the job right.  I do
not think that there is a quick fix to a long solution.  With a lot of
care, you could tap and repair on the car, but just one piece of metal
between the valve and seat on one of the valves will not be good.

My 2 cents...

Regards,
Glenn Merrell