RE: 3W 24 gas engine thrust
Pat,
My "too small prop comments" were focused on the 18 x 6 Zinger. I am sure I can guess the pitch of the 16" prop. No need to.
Oil mix:
I ran my engines on 50:1 syn oil with no problems and all of the run time was WOT on 30 lb airplanes pulling draggy samplers.
Elson