Tom Hall of San Francisco, CA, asks:
I've been told by several mechanics that it is desirable to open the throttle completely, ie, top power/speed, to let the engine burn out excess carbon, etc. They say this is all the more important when operating at relatively low hp output, eg, 1500 rpm, which is what I use on my N40. And if this is desirable would this apply to the wing engine too?Also, what do you estimate the Lugger hp output is at 1300, 1500 and 1800 rpms? Thanks, and great to read of you trip.
Jim
Leishman responds:
I estimate the horse power output to be 30 hp at 1300 -- 50
hp at 1500 - 75 hp at 1800 rpm. I think the practice of running
the rpm up to maximum - after long periods of running at lower
rpm - cannot hurt - but I don't think it's necessary on this
engine (Lugger 668). We ran continuously at 1400 - developing
about 40 hp and after a few days - I ran up to full power.
There was only a slight amount of smoke and then it quickly
cleared up. I think that running an engine up to full power
after long periods of low speed use is more important on a
turbo charged engine. I've run our larger NORDHAVNs with the
6108 and the 6125 (both Luggers) and found that after low
speed running a shot of fullpower would result in a heavy
black smoke burn out which took maybe 30 seconds until it
cleared.