Spark Plug Blow Out

[lilblue1970]

Help needed. She is a 1970 1600 Bay. A few months ago she spat a spark plug out. I just thought I hadn't tightened it enough so just put it back in. Tonight, she spat the same plug out and now it won't screw back in. The thread is fine on the plug, so could the engine thread be stripped? If so, what can I do to repair it? Cheers.

 

[StuF]

remove the head and install a helicoil - quite a straightforward job
or as an alternative just replace the head with another, could be done in a day easily rather than messing about with the helicoils
heads can also crack causing the spark plug to blow out

 

[Davydomes]

We had an engine with a helicoiled head. The sparkplug blew out like a bullet! Luckily no one was hurt. I would replace the head if I was you.

 

[ozziedog]

As said above ^^^ helicoil is fine but it’s got to go in nice. If you manage to squidge one in without taking the head off, I don’t think you could do a very nice job and that would surely lead eventually to the said Exocet rocketing about in your noisey cupboard. So like most jobs on one of these beauts, if it’s done nicely then it should last, if it’s a bit of a compromise then it’s just the timing of thenext breakdown .. Nice idea to have a spare head anyway. I think, possibly sort out a new head and swap it over , then get someone in engineering to whack a helicoil in and keep the head as a spare.

Ozziedog,,,,,,,, ,, might be past it anyhow :mrgreen:

 

[K@rlos]

We had an engine with a helicoiled head. The sparkplug blew out like a bullet! Luckily no one was hurt. I would replace the head if I was you.

Wasn’t done properly then.

 

[lilblue1970]

Thanks for the replies. Should I just bite the bullet and get a top end rebuild kit? Do I need any special tools to do the job as I haven't done it before? I'm competent with mechanicals but never done a rebuild. Is it relatively straight forward?

 

[Davydomes]

We had an engine with a helicoiled head. The sparkplug blew out like a bullet! Luckily no one was hurt. I would replace the head if I was you.

Wasn’t done properly then.

May be, may be not. Depends on how many times the plug had been in or out by the previous owner. If it was overtightened etc. But it is no substitute for a properly sized tapped head in my opinion.

 

[Happystamps]

If you're looking at new/recon stuff, I had a shop around a few months back and TES sell about the cheapest stock recon heads you're going to get.
You'll need exhaust gaskets, inlet manifold gaskets and a new rocker cover gasket on that side. No particular need to touch pistons and cylinders etc.

 

[lilblue1970]

Cheers one and all for the input. I've decided that for peace of mind and the fact she's been round the clock at least once, I'm going to rebuild the top end on both sides. The old girl deserves a treat.