Just trying to find out how hot glow engines usually are supposed to run. Has anybody taken any readings of this? I've got a temp gun at work that I've been playing with.

We thought my OS160 was getting hot, and using a temp gun, it was never more than 200 degrees.

Mike

I've never checked any of my engines, but it seems like around 200 F is about right. MIP (I think) makes a real nice "on board" thermometer. I think it loops around the cylinder or head with a noose type thermocoupler. It seems R/C car guys tend to pay more attention to engine temp. I read that temp varies greatly depending on where you take the reading from, and it can be difficult to compare different engines due to head and cylinder fin designs. Some rely on the "touch" test or the "spit & sizzle test", but as long as an engine runs strong and does not show high temp discoloration of piston or burn up plugs, it's ok.

I run cars also and the correct place to take the temp is at the top of the cylinder near the glow plug. There are several onboard temp sensors out there all for about $50. Unfortunately I believe all of these are the wire loop type and won't get a very accurate reading since they aren't at the top of the cylinder. I figured that 200*- 250* was probably normal for a glow engine. Mine was running around 215* the other day and I was thinking, "ok...but am I overheating?"

250 degrees is a good target point for best performance and reliability for RC airplane use.
I know RC car drivers tune their engines to about 275 degrees and most heli pilots keep theirs at 225 degrees or slightly lower for even more reliability.