Home › Forum › Ask A Member › Choosing a prop › Re: Choosing a prop
June 26, 2017 at 6:42 pm
#60405
On my grandson’s hydroplane (which I drive too) I’ve had from 6 to 15 HP on it – all stock motors without special props. Due to the higher RPMs, I always go one heat range colder on the spark plugs (had to go 2 ranges colder on a 1953 8.4 HP Champion). I increase the oil mix too, like 20 or 25 to one with a 50 to 1 or 100 to 1 motor – actually I never run 100 to 1 in anything, even if that’s the spec and gentle use. Note that the Champion class B "hot rods" made for racing from the factory were spec’d at 4 to 1 gas/oil mix (that 4 is not a typo).
Dave