Slant 6 Turbo 68Dart Project

Anyways, pulled the other plugs and apparently leaving the washer off was a bad thing, because there was oil all over the outside of the plug sitting in the drool tube on every single plug. No oil in the firing range though, which I was worried about initially - going oh god my rings are gone... but no - it's outside, and the plug was not making a seal against the tube without a washer. I put it on, and it looks good to go on the new plugs.


I don't know where I read it, but I have read it several places, that if you have a drool-tube head, the drool-tube is there,partially, to act as the plug washer... and no other washer is supposed to be needed; the theory being, that the heat-exchange between the head and the plug will be impaired, and the plug will run hotter, if two gaskets are used, and that is, effectively,what you are doing with the use of both the gasket AND the drool-tube.

Take that for what it's worth; you might want to research it on your own...

Additionally, I have also read that turbochargers and extended-tip spark plugs are not a good "mix" because the extended tip, living in an environment of fire, as it does when the engine is under boost, will glow cherry red and can cause detonation (due to pre-ignition,) the ideal configuration being a tip that extends no farther into the combustion chamber than the surrounding ring of the plug body. In other words, a conventional, old-style plug. There are plugs designed specifically for racing,which have an electrode that is level with the "top" of the plug body, horizontally configured) that are specific for forced induction applications, but they are not stocked by anyone other than speed shops and online sources. They are the best, for engines like ours. NGK makes them.

Food for thought...