I am interested to hear opinions on acceptable start times, from initiating the start to the ecu handing you back throttle control once the engine has reached idle. With the advent of kero start engines start times have grown longer, certainly when compared to a gas start engine.

I have been fine tuning the settings on my Mammoth KS to suit our UK climate, engine now starts in around 90 now with no flames but because there is such a large chamber the majority of time is spent in the pre-heat stage actually heating the chamber/sticks.

Rob.

I'd say just about any time is acceptable as long as it results in a successfull start. The different brands I have start from very slowly, such as my AMT Netherlands Pegasus and Olympus (maybe 30+ seconds to idle?) to my AMT USA AT-450 in about 15 sec. The JetCats seem to be somewhere inbetween. These are all propane start.

I guess it has to do with the size/strength of the starter motor and the "ramp" schedule programed into the ECU. I always sort of assumed a slower start was easier on the turbine as it gets up to temperature.

Craig

I am with Craig on this one. I have a pair of Mammoths back in the 262 now and they start so smoothly and with little fuss that I dont worry about the time. Yes the longer than normal pre heat time took some getting used to at first but I wouldn't say its massively different to other turbines of its size that I run.
Regards Al

Thanks gents, so it sounds like what I had in mind (so long as the start is smooth and flameless) the time is not of primary importance.

With a few tweaks/adjustments between temps, burner and stick flow I got the time right down without compromising the already good kero start.

Other than the kero starts I have seen at flying events and normal club flying (and those are usually a hidden from sight internal install) I could only really find video of one which showed what I needed to see from an engine in the same thrust class, problem is it is a hot restart and there is some flame during the preheat phase so possibly not typical.

Anyway thanks again for the feedback, definitely one of the positive things about RCU

Rob.

I just ran my new Kero Start Jet Central Cheetah, from the start command to the "Running" status it took 30 seconds!

So long as it is starts first time everytime with minimal flames, time is not important unless you are looking to do in flight shut down and restarts, cant see any real need for very fast start ups.