missing issue & valve cover gasket

[thedguy]

I've got a roughly 280k mile m42. I say roughly because the odometer was broke when I bought it and broke twice on me since I've had it in 4 years.

I managed to chase out most of my oil leaks but I have one left. The valve cover gasket. I've already had to heli-coil the damn thing on nearly every bolt hole except the 2 in the spark plug valley (I have a COP conversion). I did re-use all my old bolts, and I'm 90% sure that was a bad idea on many accounts.

So my question is, can I re-heli-coil them again and put fresh bolts in with fresh grommets and a new gasket to possibly fix my issue? Also/alternatively is there a better option then helicoils? A major issue I was having was installing them when I had to stack the inserts since the depth was may more than any 1 insert.

More important issue, I noticed that cylinder 1 and 4's spark plugs were coated in oil on the threads, though the tips looked decent (and they are some shitty splitfire ones btw). I have tried to check for vacuum leaks, and my injectors are rebuilt as of less than 100 miles ago Ford 19# 4 pintle injectors. Is this likely to cause my missing? How the hell is it only 4 and 1 have oil on the spark plug threads but not 2 and 3, there are no bolts down the center valley near those 2?

What spark plugs would any of you guys recommend for this engine? I know the split fire ones are shit (or anything with more than 1 ground strap), but anyone have any better luck with anything specific?

[roguetoaster]

I've got a roughly 280k mile m42. I say roughly because the odometer was broke when I bought it and broke twice on me since I've had it in 4 years.

I managed to chase out most of my oil leaks but I have one left. The valve cover gasket. I've already had to heli-coil the damn thing on nearly every bolt hole except the 2 in the spark plug valley (I have a COP conversion). I did re-use all my old bolts, and I'm 90% sure that was a bad idea on many accounts.

So my question is, can I re-heli-coil them again and put fresh bolts in with fresh grommets and a new gasket to possibly fix my issue? Also/alternatively is there a better option then helicoils? A major issue I was having was installing them when I had to stack the inserts since the depth was may more than any 1 insert.

Of course there is a better solution that helicoils, take the head off, send it to a machinists where they will fill, redrill and tap new threads. You can do the same at home (only for low torque applications) if you slot the holes, fill with a decent metal filler, like labmetal and redrill/tap, but it will probably come out badly with the head on the car.

I do wonder what the issue is after fixing the threads. Are you over tightening? Is your VC gasket past it? Are the grommets on your bolts perished? Are the threads on your bolts damaged?

More important issue, I noticed that cylinder 1 and 4's spark plugs were coated in oil on the threads, though the tips looked decent (and they are some shitty splitfire ones btw). I have tried to check for vacuum leaks, and my injectors are rebuilt as of less than 100 miles ago Ford 19# 4 pintle injectors. Is this likely to cause my missing? How the hell is it only 4 and 1 have oil on the spark plug threads but not 2 and 3, there are no bolts down the center valley near those 2?

What spark plugs would any of you guys recommend for this engine? I know the split fire ones are shit (or anything with more than 1 ground strap), but anyone have any better luck with anything specific?

If your plugs have oil on them it's a plug well gasket failure. Further, the spark plug well gaskets fail at different intervals, with the odd shaped one failing more frequently on my M42. If your plugs are getting a bad ground that could easily account for misfiring, or it could be cruddy plugs, or even bad connections somewhere in your COP setup.

As to plugs, the Bosch 7402 (which are two ground) that are spec'd for the car have served me well, as have NGK BKR6EKs. I wouldn't go so far as to say that every other plug is crap, but it might very well be.