Engine temps?
 

Wondering if anyone ever tracks temps on their engines. Running in a couple of engines yesterday, I noted newly ringed engines( a 45 4S, and a 61 2S) ran about 170 degrees on the first 1/2 tank, or so, and worked their way down to about 160 deg-+ or_. Wonder, therefore, what a normal operating range would be. Temps sure seem important in full size engines. Bill

RE: Engine temps?
 

In tracking your temps, try to standardize the position that you take the temperature from because when the engine is running, they vary considerably. Take your temperatures with the engine running. Heat soaking will distort the readings on a stopped engine.

On the two stroke, measure right beside the glow plug on the exhaust side of the cylinder head.

On the four stroke, measure just above or behind the exhaust pipe.

Getting to 300 F is getting too hot.

Establish base lines on all your engines so you have a comparable later on.

RE: Engine temps?
 

There are no published specs on engine temps for glows. Usually when you engine overheats, its too late because your already in the air and your going to lose power and or quit altogether. Usually from a lean setting. I do this once in a while and just let it cool off, readjust and fly it again.

RE: Engine temps?
 

Tune your engine to run well, and take it's temperature. THAT's normal. This winter, "normal" will be something else. If you change props, or mufflers, or fuel, or installations (cowled vs uncowled), well....then "normal" will be something different again.

Because of the wildly varying installations, tuning, etc....There is no one size fits all "normal" temp.

Temp guns should have a sticker on them that says "For entertainment purposes only".

RE: Engine temps?
 

Temp guns are really the #1 "sucker buy" in the hobby. However, very useful when pointed at bugs, beer cans or the wife when you get home 5 hours late. Anybody have a "golf watch?

RE: Engine temps?
 

The problem with temp guns is that they don't actually measure temp, they instead measure the infrared light then they compute what a 50% grey body's temp would be if it radiating the same infrared light. A shiny polished aluminum Fox engine would be running hotter than a black Saito BK if the temp gun said it was running at the same heat. Or in other words if a shiny polished metal and a black metal were at the same temp the temp gun would say the black metal was at a higher temperature. Good for comparison for the same engine with the same equipment and fuel only.

RE: Engine temps?
 

Just for grins I went out and put my Magnum 46 XLS on the test stand. Fuel = 15% Byron's, Air temp = 92F, prop = MA Scimitar 10X7.

Full peak = 15,100 rpm's and showing 285 degs F on infrared.
300 rich = 240F
500 rich = varied between 210 and 230.

I normally run it about 300 down from peak.

Like the others say though, temp doesn't tell you anything about your mixture. Too many variables; I just peak it then back it down about 3 or 400 and fly it like I stole it. [8D]:D[8D]

P.S. These numbers are with a Tower muffler on it. It doesn't turn near that many R's with the stock muff on it and probably runs cooler too, although I haven't checked the temp with the stock muff.