ORIGINAL: colingw
ORIGINAL: 1705493-AndyW
Colin,
Ether may go the way of the Dodo if the runs on my own PAW are any indication. We may not even need ether in the prime. But you're right, throttling can be an issue on pure kero. More to come.
Andy,
What was the fuel mix, and what was the starting like? Any special starter mixture, or an electric starter?
OK, this has me fired up to try a fuel with say 25% castor, 1% redex, 1% DII and the rest automotive diesel fuel. Maybe make some priming fluid with john deere starter, or even just acetone. (This will just be bench running, I don't have a plane for the PAW yet, having just re-started control-line after a 20 year absence. I'm building my first planes in 20 years at present, but using glows, a Cox .049 in a 1/2A 'Stunt Chimp' and an OS MAX-III .15 in a Brodak JR Flite Streak respectively.)
I have a feeling the PAW 19 may run and start better on this than the MARZ 2.5s and the PAW 80 (.049). (My MARZes and the little PAW aren't broken in yet - the 19 is relatively high hours and was always a two flick starter even on 10% ether).
One additional data point: my flying buddy in the old days ran a PAW 249DS. I seem to remember it was a bit cranky starting on the 10% fuel I made up, but he tended to run a small prop at high revs where I had a 9x6 or even a 9.5x6 on my .19.
By the way - I'm so glad I found this forum (pointed out to me by someone on
www.clstunt.com ). Great to find plenty of other 'oily hands' out there.
Colin,
By now, all the PAW videos are posted and should fill you in.
Acetone, as Kelly has informed, was going in the wrong direction. I was looking at it as a highly volatile fluid but its cetane rating stinks. It's actually an octane booster used sometimes to smooth out glow power runs. Cetane and octane are like yin and yang.
Can we assume that Redex and D11 are cetane boosters? These are down under products? If so, as my preceding post indicates, you may have good luck at 5 or even 10% concentrations.
You're right mostly, that the bigger the engine, the less fussy they are but for the small ones, it's just a matter of getting the mixtures right at all throttle settings.
But wait, your buddy ran "small" props on his .19? And you ran "big" props? A 9 X 6 is common for a glow .19. I'm remiss in not mentioning that, typically, to push the diesel concept, I run .06's like the PAW and Norvels on 8 X 4 props. And they like that a lot. Are you running diesel WAY too fast? My .15 was tested with a 10 X 4 and sounded so good, that it WILL be the prop I'll use on my small Pitts.