Glow Plugs (check 'em often)

Pulled some of my "stash" motors out this evening for a periodic look-see. Everything from a pair of Atwood Triumph .51s to a Fox .35 Stunt sandcast, to a pair of O.S. Max .15 steelfins, and four McCoy .29 rear intakes.
Three drawers full, about half of which have dead or marginal plugs.
Eventually, all will get put on planes. but I should have learned better after all these years: "If it doesn't glow BRIGHT, it isn't right!"...
Oil ALL your motors promptly after each use (and at intervals between) and trash all glow plugs that aren't 100%. Saves lots of grief (and $s), and lots of flipping and not flying at the field.

It might make sense to store your "stash engines" without glowplug anyway. Then you can easily turn it over by hand, add some magic after-run oil, and be certain that it is well lubed. Steve

They are ALL well oiled anyway (including the diesels), but some of the plugs that were OK a year or two ago, no longer light up as well as they once did.
Some do, and some don't. Like all things, quality varies, and there are things that will last 50 or 100 years or more without a problem, while others are gone and dust in two or so. It all just depends.
In other words, before you head to the field, check the plugs...

Speaking of things that would last, versus short-lived things is mindful of a question I had for myself that I couldn't answer. A seller on eBay had a sizable number of OK Cub glow plugs and a really exorbitant idea of how much they might be worth now.

I recall using those quite a lot near the beginning of my model career, but not what quality they were or what heat range. Later on, I know I was using other brands much more than the OK's - I suspect that they were less expensive than average, but haven't even a vague idea any longer.

I do recall the Champion glow plugs were more expensive than I thought I could afford while they were still available. Weren't those OK Cub plugs at least fairly decent for ordinary sport flying?

There are a lot of things from the Way Back When that I remember better than glow plug choices. Anyone else manage to hold onto more of a recollection on those?

The K.

Kiwi,
I remember using OK plugs too. Still do, in my Cubs. OK plugs are still being made. Brodak handles OK stuff.
I still have a couple of Champion Shorts. I remember reading shortly after they became unavailable that technology had advanced and there were better plugs available...still, I liked those Champions.
George

My recollection of the OK plugs is that they used cardboard insulators that could leak. If it can, it, eventually, will. Eventually didn't usually take too long on those plugs.

Use them on your collectors. Don't use them for serious.

>My recollection of the OK plugs is that they used cardboard
>insulators that could leak. If it can, it, eventually, will.
>Eventually didn't usually take too long on those plugs.
>
>Use them on your collectors. Don't use them for serious.
>
OK, I had a vague recollection that I couldn't use them on anything with very much in the way of compression, but not "why" that might be so. Which plug type was it that blew out so much of its insulator, or blew it so badly, that the center post was left flopping loose in the body, or even might be completely missing?

Another plug I used quite a bit in those "way, way back" years was the Ohlsson "Gold (something)" plugs that were supposed to last almost forever and now I can't recall if they came anywhere close to their advertised service life. I know I didn't have much luck with Fox plugs at any point before the most recent years, whether they were "2 Volt" rated or whatever.

I did have some Veco plugs that soldiered on year after year without fail, long after any more of the brand were available.

Kiwi

LAST EDITED ON Apr-14-01 AT 01:21 PM (EST)

Kiwi,
Could that be "Gold Seal"? I have some O&R plugs but they are "Kwik Start".

Leonard,
I blew the insulation out of a plug yesterday while breaking in a TT .15. When I tried to start it the second time, there was NO compression. Panic time..until I gathered my thoughts and checked the plug. First thought was peeling, but this was a TT
Think it was an old fireball, but I'm not positive. I guess you are right. Save the old plugs for old sport engines.

How good are current Fireball plugs? I would guess that they have "evolved" the same as engines have. Perhaps OK plugs, also.

Yup, George, they were Gold Seal. I haven't had the chance to try then in CL yet, but some of the most durable plugs I ever ran in RC were the OS, Rossi or NovoRossi and McCoy. I intend to do some playing with these, depending on what I can get and in what heat ranges. I have a twenty year old OS 40 4Stroke with the original OS plug in it that still fires without fail.

My understanding is that almost all U.S. made plugs are, and have been for many years made by O&R (or by their descendents whomever they might be).
Like lightbulbs, I have had some plugs that lasted years, and others that went kaflooey in one or two runs. It seems to just all depend...
The old Champion plugs were kinda cool looking, if nothing else. They really don't make stuff like they used to (grins).

LAST EDITED ON Apr-16-01 AT 01:57 PM (EST)

>My understanding is that almost all
>U.S. made plugs are, and
>have been for many years
>made by O&R (or by
>their descendents whomever they might
>be).
>Like lightbulbs, I have had some
>plugs that lasted years, and
>others that went kaflooey in
>one or two runs. It
>seems to just all depend...
>
>The old Champion plugs were kinda
>cool looking, if nothing else.
>They really don't make stuff
>like they used to (grins).

Yes, there were (are) only a few plug manufacturers in the US. There was Cox, Fox, Twinn-K (GloBee), Swanson (Fireball) and (I think) Ohlsson, who OEMs plugs for everyone else, including K&B and McCoy.

Fireballs were notorious for blowing seals - I can't say I know - I have not used any - but I've had it happen on a Fox Std. Long once. Engine went from a combat run to sounding like a motorboat.

Some of the Ohlsson plugs, particularly those available recently via McCoy, have .008"-diameter wire, rather than the .004" or .005" stuff that has been the U. S. norm for a few decades. Many old plugs had fat wire, too. These may be the ones that aren't lighting up brightly. I'll take them if you don't want them.

About 1973 Fireballs were the only plugs I knew about with good wire, but their seals were bad. We would use epoxy or strain-gauge cement to seal them, with mixed success. Things are better now. Good plugs are available, and engines are easier on them (the 10%-nitro requirement in F2D helps).