K&B .09 Torpedo Engine

Dave, as of late I haven't been doing much with model planes for the past 7 years, so as time flies, I can only relate to the earlier years when younger.

In college late 1970's, I had a 1965 model OS Max .10R/C (the one with throttle exhaust valve ganged to the carb via link for idle without muffler) on my 39 inch span T/F Ken Willard R/C Schoolmaster. I bought a Fox short idle bar plug for it, but had the darndest time getting it to properly fire and run. At Hobbietat (local fishing and model aircraft supply), I purchased a hot short Swanson Associates Fireball Red plug without idle bar.

On SIG 25% nitro Champion all Castor fuel, it fired up immediately, had many successful flights until I graduated from college.

I didn't know any better, it worked, some may accost me for not going to a medium plug. However, the hot worked well, would gain altitude, then glide down on extended idle, easily ramp back up to high throttle.

At the 6,500 foot elevation of Gallup, New Mexico, I put that engine in a half-A foam Piper Cub, and flew it on hot standard plugs and 10% - 15% nitro fuel. Here in Clovis, NM at 4,300 foot elevation, been using both a combination of medium and hot plugs on same nitro of fuel on anything from a Norvel .061 with plug head and R/C .09's - .15's and C/L up to .35's, my Testor Red Heads.

I by no means are any type of an expert and basically say for yourself to try and find what works best with your engines, fuel and flying environment.

What works for one doesn't always work for another, and one is best off finding what best works for them.

One thing I did do was buy some Chinese hot plugs on cards of 10 or 12, when they were going for under $25 before Covid. Now I am glad that I did, as with the surge in platinum prices and inflation, plugs have escallated in cost, easily trippling and quadrupling.

I also made a mistake of buying a full card (10 to 12 plugs) of NOS Swanson medium yellow Fireballs about 10 years ago. These didn't work like the ones I bought previously. It would fly well on my muffled 1965 model Enya .09-III TV for a couple days new. A week later, I'd only get pops and fizzles, until I replaced it with a new Swansons. Then I flew like new, fizzling a week later. Did this with most of the card.

Doing a little on-line research on some C/L websites no longer available, like Stuka Stunt and Brotherhood of the Ring, found that for a couple years in around the late 1970's / early 1980's or somewhere thereabout, Swanson had received from a supplier, defective Platinum coated nichrome wire for the plug element. The Platinum was unstable and eroded quickly in use.

Too late to return plugs with too much time passing, I chaulked it up as a learning lesson.

I state this just for your awareness. For a short time, I heard something similar happened to Cox when Leroy was still owner. I think this also happened to Lou Fox of Fox Manufacturing with his plugs for a time.

Yet, the old Enya 30 plug that came with my Enya .09-III TV still worked after all these years. So, just stating this for awareness on some NOS plugs you might find. Although most I'd say were good, it is possible to receive a dud batch.