Calling sosam, over...

Coxfledgling wrote:Sosam, sir, I am hopeing you can advise...

I have an Enya 15 TV marine engine having a deflector type piston, so loop scavenge.

I have a wooden boat 32 inch long by 25 cm wide, semi planing hull, that will accommodate a 40mm propeller.

I know this may be difficult, but what pitch of prop would you recommend please.

Would going down in prop diameter help ( probably would I think ) but what pitch would you suggest please ?

Thanks in advance, rich.

Fledgling,
I emailed a friend of mine (Skip Horseman) that has done R/C boating (in many forms - racing, scale, sailing and even subs).

He replied back to me giving me the information:
Skip said, " A good rule of thumb for a general-purpose model boat prop is the pitch/dia. ratio of 1.4 gives good efficiency and speed for both submerged and surface drives."

He suggested for your boat -- starting off with a 3214/2 prop.
Which is a 32mm prop diameter with a pitch of 44.8mm on a 2-blade prop.
From there you can move up to a 4014/2 or a 3514/3 (3 blade)?

Here is my Kyosho Jet Stream GP-10 --- It has an OS-.10 glow engine.
The prop on that is 3014/2 (dia. 30mm / pitch 42 / 2 blade prop)
Boat dimensions: 900mm bow to stern - excluding out drive / 187mm beam width / 140mm keel to top deck.
ABS plastic hull.

Haven't run it in over ten years but did look it over this year and everything is still good as new.