Engine run-in

tallus

Ok Guys , got a question here, is it normal for an engine to get pretty hot while idling ? I never really noticed before but was running some fuel through my savage 3.5 earlier and notice that the engine was running quite hot just in the idle position. She had been running for about 15 minutes idling when I checked after the engine stopped. I'm not running her too lean because I was getting plenty of smoke from the exhaust, just wondering if anyone else has experienced this ? I'm afraid of seizing the engine Dynaglo 16 fuel.

T-Maxx

Idling for 15 minutes? Geez. Why?

Remember that these little motors are air-cooled and therefor need air movement around it - something that doesn't happen when it's sitting idling. Also, how hot is "pretty hot" and how much smoke is "plenty"?

tallus

Part of the run in process according to HPI is that you run a full tank of fuel through the engine at idle speed, twice.
Pretty Hot: you can't keep a finger on the head any oil or fuel on the head was starting to smoke from the heat.
Plenty of smoke: it's running slightly rich

T-Maxx

Temps sound fine to me. It's when the head is clean and smoking from moisture in the air that it's too hot. And if there's plenty of smoke (like in rich), I wouldn't worry about it.

(BTW I bought a little infrared temp gauge for $24 - I don't tune by temp but it's always handy to have in your pit box.)

tallus

Ok cheers man thanks :-)

coolwings

From Model technics website.....
Dynaglo contains 8% E.D.L. (synthetic oil) and 2% castor oil .... plus nitromethane .......

10% oil blends are designed for big low revving aero engines, and four-strokes.

Model fuel with only 10% oil in any car engine will cause it to run hot. (Unless you set things v-e-r-y rich, which will detune it.)

Those high revving engines are designed for fuel with minimum 15% oil, better still 18-20% oil.

tallus

Ok thanks guys :-) The help is appreciated :-)
*edit*
Coolwings you were dead right on that oil thing the manual says 20-25%