[foxmoth]

Looking for a new set of plugs (Lycoming o360), I notice the Tempest ones are much cheaper than the Champion, does anyone have experience of these, happy to pay more if the Champions are really better but often that is not the case? Other recommendations welcome! Also looking at the tables it seems there are 3 alternatives -40E, 38E and 37E, any recommendations here also appreciated

[GrahamB]

A year ago at the last mag overhaul I treated my O320 to a set of Tempest plugs. Within a short while I had an intermittent misfire in the air - it was never apparent on any ground runs - which was quickly diagnosed with the EDM830 to a particular plug.

For some weird reason, a huge gobbet of lead fouling had appeared on that plug within a few hours of running from new. It had never happened before and it's never happened since, but we swapped it for another and harmony was restored. What was interesting was that before cleaning it, we put the fouled plug on the spark tester and you could clearly see that it was actually trying its best and still sparking, although weakly, despite the fouling.

My engineer had said he'd never seen a Champion plug manage to spark at all with that amount of lead and was quite impressed.

IMO Tempest are not only cheaper but also better!

[Marchettiman]

I changed from Champion to Tempest plugs (Lycoming O-540) two years ago and have found the engine runs noticeably smoother and starts more easily in really cold weather.
I also use the technique of aggressive leaning when taxying as these engines run very rich at low rpm. As a result I never get any lead fouling of the plugs, and the oil stays clean for much longer after an oil change.

[Rob L]

I would also agree with the Tempest plugs (and oil filters, while we're at it). A personal opinion.

The best plugs, if they suit your engine, are the fine-wire plugs, but check they are suitable for the engine/aircraft.

[johnm]

Another vote for Tempest plugs and filters in IO540

[Awful Charlie]

And another upvote for Tempest fine wires on a TIO-540, although I've not tried the Champion fine wires
The previous engine had over 1000 hours on a set of Tempest fine wires with minimal maintenance (not that much is possible!)
When I put a new engine in a couple of years ago, it came with Champion massives, After less than 100 hours the wear was obvious, exchanged with Tempest fine wires and no problem since.
The Tempest oil filters have a magnet in the back, not sure if Champion have added that since I dropped them

[Rob L]

....not sure if Champion have added that since I dropped them

(my snip)

Not in my experience. Mind you, I have personally yet to see significant metallic residue on the Tempest oil filter magnets (and I do check!) I suppose the first impending signs of major internal failure are likely from babbet material which is of course non-magnetic (but should be visible in the paper filter element).

[Charles Hunt]

Heard of Bobbit, not Babbet; Google tells me it's Babbitt. And then that it is a 'white metal' which I have at least heard of in connection with bearings.

[CloudHound]

Just replaced plugs in the RV-6 with Tempest. Lycoming O-320.

Used to churn and churn and if hot churn some more.

Not run for a while but fired before 4th blade then ran sweeeeeet

[Rob L]

Heard of Bobbit, not Babbet; Google tells me it's Babbitt. And then that it is a 'white metal' which I have at least heard of in connection with bearings.

OK, Babbitt then. My apologies.

[Charles Hunt]

No apology needed. I just thought that for those of us seeing the word for the first time it would be beneficial to get the correct spelling. My 1963 Observer's book of a/c had an entry for Yakolev, and this is the spelling that stuck in my brain. I was somewhat confused 50 years later when I started reading about Yakovlevs. Still looks wrong to me.