Spark Plugs

[pa20]

So, other than cost....Does anyone have an opinion on what plugs seem to give the best performance for our Lycomings?

[Pacer 24C]

No question about it TEMPEST!!!!! Less cost , better plating, I just removed a set with almost 600hrs for no good reason - still good and cold resistance of average 1000 ohms, absolutely get UREM37BY's - same price as 40E's and way better if you use 100ll

[rwdurham]

Absolutely agree with Pacer 24C. Last longer, foul less. They are expensive but never regretted going to them.

[Steve Pierce]

Tempest, less $, better plating (no rusty barrels), no antiquated carbon pile resistors.

[rocket]

Here is my experience with the Tempest plugs;


The machined finish is really rough and as an A&P the last thing in the world I want to do is screw around trying to get a set of plugs or leads disconnected or installed while getting eaten alive by misquotes. Not too big a problem in our little Lycomings but on the six jug spam cans…not much fun. In another life I worked in a machine shop where we broached/blind broached corrosion resistant parts for NASA and there were all kinds of issues with this material and how we kept the finish within tolerance; mostly just large tumblers of abrasive. It is not rocket science.


The tempest plugs have the hex for removal about 3/16 (?) lower and requires a deeper socket! WTF! Anyone out there have a Leading Edge exhaust on a 206. About five years ago my overhaul shop stuck a set of Tempest plugs in a IO520 I installed. Along comes the first 100 hour inspection and I was f*****. The LE exhaust comes with a special socket to remove a couple of the bottom plugs and it was too short to engage the blankaty-blank roughly machined POSs. Can you tell I still harbor some residual anger for having to drop both exhaust stacks just to pull a couple plugs; while getting eaten alive by misquotes, white sox, and no see ems. Steve, I bet those plugs are still look shiny and new…at the bottom of the Naknek River :/


Now for the tempest "fine wire" plugs. Take one Tempest and one Champion, hold them together side by side, and take a good look at the business end of them. What do you see? On the tempest you see a large flat ceramic insulator just under the side electrode just the perfect place for a gob of lead to foul a plug. Been there, done that. BTW, the Tempest fine wire plugs don't float ether…


I have a Champion massive plug go south on the R985 a few times a season but can't recall having bad plug on any Lycoming or Continental… I find the ceramic cracked on two or three fine wire plugs (used on back plugs of round engines) out of the 150 of them I see at annual and about the same number of massive fail in my plug tester.


Other then the Tempest fine wire lead foul a few times I have never heard of anyone having a operational problem with the tempest plugs and I have to say that is what really what counts…and they are cheap!


Enough of this, its time to take a soap sample from a Garrett burner…


Rocket

[Lownslow]

Here is my experience with the Tempest plugs;


Steve, I bet those plugs are still look shiny and new…at the bottom of the Naknek River :/



Rocket

It might be interesting to hear what else may have wound up there... like maybe some of the junk batteries we have to buy these days that don't last.

Lou

[Pacer 24C]

The Hex reach is only a problem on 38 or 40E (Tempest 37BY's are shorter and the shorter socket works fine) - I would never use a 40E if the 37BY's are approved for the engine like our 0320's 37BY's are massive electro and same price as 40 E's

[philiplane]

It's true that a standard 3/8" drive deep socket will not grab a Tempest plug completely. A 1/2" drive deep socket will.

But the standard 3/8" drive spark plug socket works on a Tempest plug or a Champion plug. Folks should be using a specialized spark plug socket anyway instead of a regular deep socket. The retainer built into a specialized spark plug socket prevents dropping the plug from the socket after removal. I see several hundred spark plugs annually and I will no longer use Champions.

[pa20]

It appears that the jury has indeed reached a verdict!

[Steve Pierce]

I have never had issues with the Tempest finish but I have several old PWA spark plug sockets for the large and small barrel plugs.