shortfielder wrote: I am aware of the fine wire being better. But I ain't got $500.00 for a set of plugs.

Make that $1,200 for a set top & bottom.

GumpAir wrote:

shortfielder wrote: I am aware of the fine wire being better. But I ain't got $500.00 for a set of plugs.

Make that $1,200 for a set top & bottom.

You got that right. And imagine if you dropped one!

Although they are meant to be a lifetime part - lifetime of the engine that is. Guess they would still get fouled like any other plug?

Are you able to mix different types of plugs?

Two years ago I replaced my Champion plugs (fine wire on the bottom, massive on top) with Tempest plugs. The Champions did not appear to be worn out but the resistance through more than half of them was through the roof. Tempest plugs were much cheaper than the Champions. I have been very happy with them, no issues at all. I was getting lead fouling on the Champion fine wire plugs occasionally. No such problems with the Tempest.

Mr. Ed

Last annual, my plugs looked great but resistance was out of sight so I ponied up and bought some new ones. A buddy of mine swears by 37BY's-- he says they never lead foul but since I've always ran cargas or mostly cargas (50/50 woith 100LL these days), I've never had a problem with that. So I bought UREM40E's. Anyway, I thought I'd test resistance through the new plugs before installing. Low & behold, I got 1600 ohms through four and 2100 ohms through the other four. WTF? I thought new spec is 800-1200. Yes it is for Champions, but Tempest's website indicates up to 3000 is within spec. That surprised me. I've been hearing how much better the Tempest resistor design is than Champion's which is one of the reasons I bought them-- the other is that Tempests are cheaper. Guess we'll see how the resistance reads a few years down the road.
BTW common wisdom seems to be to expect about 500 hours out of a set of plugs before the resistance gets too high, and that's pretty much been my experience. I think a Bendix mag will spark a borderline plug when a Slick won't-- that's the price you pay for the smaller cleaner-looking design of the Slick which has a smaller, less potent coil. I like the small size & 360 degree-capable mounting of the Slick, but will stick with the Bendix for performance & longevity sake.