Just curious, how often do the majority of contest Top Guns change glow plugs? For instance, high rollers at the NATS, do they change after every flight?
Oh my goodness, no. In fact you never want to do that without the opportunity to test it. I can't speak for anyone else, but I usually change right before I leave for the NATs, and then the first flight, I do some inside and outside loops and listen for any issues, before trying a wingover. After that I leave it alone unless there is a problem. If there is a problem, I switch to the plug I just removed rather than a new one.
Having said all that, I have yet to have any big problem with brand new Thunderbolt 4-cycle plugs (PA and RO-Jett) or Glow-Devil #300 (VF) or McCoy MC55 or 59. The only "problem" plugs are Fox, which seems to be a QC issue, and Rossi - which I suggest you NEVER EVER use under any circumstances. The Rossi plugs, no matter which one I try, have very reliable flame-outs, many times with no warning and even on the ground.
Ted crashed his airplane in '90 or '91 with a Rossi that just flamed out, the instant he touched the needle. I was skeptical so I got every variety of Rossi I could find from the big-bore to the one that warned "2.5CC and smaller ONLY!", and every single one of them had the same sorts of problems from varying degress. None of them made it as far as getting released for flight without quitting.
Once I switched to Powermaster fuel, taters are no longer an issue in switching plugs, so near as I can tell there is no significant limit to the life. I can only ever see a small carbon buildup right near the end of the element going to the plug body, and I have put old plugs back in with no problems. I would guess I get at least a few hundred flights with no perceptible degradation.
Brett
Topic: Glow Plug Question (Read 940 times)
