quote:Originally posted by mike the snake:
Thanks for the info on the plugs.
I'll go with the colder of the ones I found in the car.
I assumed since the car would be 90% driven on the street, that the hotter plugs would be the better option.
The car has the MSD ignition with the big square Mallory power coil as well..
There's been a number of engines run in this car, so some of the componenets may be remnants of previous engines, still in use.
The different plug thing, I don'r know what to say about that. The plugs, the distributor being bad, metal in the engine, the entire electrical system needing work, all these are surprises I was not ready to deal with.
Normal maintenance, valve adjustment, oil changes, brakes, wheel bearings, those were the things I had expected to do myself, and as everyone knows it's turned into much, much more than that.
My plan was also to replace older parts before they failed, like the water hoses and hard lines, fan belt, just in general take good care of the car, work on it and enjoy it.
In MY experience you will be happier with the hotter plug every time.
I use the Champion chart to cross reference heat ranges in this engine. I find their chart the most accurate.
By Champions numbers the COLDEST heat range for be the f9y (in a Windsor with the bigger base diameter plug) and the HOTTEST an F11y.
With the Webers I am running just 1/2 heat range under the f11y but even the f11y would be ok as long as the fuel ration is running lean anywhere.
Ultimately if you went a little hotter to like a 12, it would essentially work as an rpm limiting device somewhere in the 5500+ rpm range. You might even hear pinging there and the caution would be that if you did, that would not be good for the longevity of the engine.
By the same token with this much "induction" in the car you MIGHT see indications of the 9 fouling, then being cleaned up. That would be some glazing on the electrodes. That would be caused by the carbon (fouling) that was remelted as you rev'd the engine and deposited on the porcelins.
I am very sure that if you went to an 8, the car would be just unmanageable with fouling plugs.
If the former "mechanic" mixed 8's and 9' or some combination because of this, then he is either very very tricky and bright OR is very dumb.
Just like the shark in Jaws, "which is he Chief?" Caution should prevail.
...oh, aluminum heads like the hotter plug rather than the colder. Has to do with a more rapid heat transfer and loss than iron heads. Don't fight that. Nothing you can do about it.
I think it is actually a drawback to aluminum heads. They are harder to tune as a result.
Hey...listen. I do not get commission for selling Jon Haas' Pantera-Electronics Ignigition BUT and this is a VERY SIGNIFICANT BUT, it fires fouled plugs and cleans them up while the engine is running. The MSD DOES NOT.
If you are going to mess with ANY KIND of carburation or fuel injection OTHER than a box stock engine, you NEED the P-E.
Just trying to save EVERYONE some self imposed bumps of knowledge and lots of waisted time.