Not only is it probably OK... it sounds like its on the cool side of normal. [img]i/expressions/face-icon-small-wink.gif[/img] Lets compare it to a car... The normal operating temp range for a water cooled engine is appx 180 to 220 deg F, and they are usually not gong to boil over before hitting 240. (15 psi radiator cap and antifreeze bring the boiling point up) An air cooled engine in a car (old VW and similar) will easilly have over 300 deg at the heads.

The exhaust temp of the engine is in excess of 800 deg. Temp in the combustion chamber will exceed 1200 deg durring the power stroke. Getting the engine to cool as well as you are... you're doing GREAT.

Its nearly impossible to "excessively" cool a glow engine, (without doing pumped water flow to a water jacketed type You can overdo that... and make the engine die.) so don't worry about trying to reduce cooling air.

Around 300 degrees around the glowplug , so as Mr Huber says you've got it right on.

Does anyone have some comparative temperature numbers on diesel and glow engines? My unquantified observation is that diesel exhaust is much cooler than glow exhaust; conversely the diesel cylinder will get much hotter than a comparable glow cylinder.

Jim