I have a 120 size Sea Master (ws approx 85.5 inches) which Ibought second-hand some time back. I'm just now trying to set up for some flying. I didn't realize until recently that the engine which came with the airplane had never been installed on the airplane. It's a Zenoah G-38 on a (huge) stick (pylon). With the engine mounted exhaust up, the 18x10 prop clears the deck by less than an inch. With the engine inverted, the pitts-style muffler pipes are about 2 inches off the deck. I can tell the engine has never been attached because the pylon doesn't fit into the pylon slot fully. Still needs some signifcant trimming.

The Zenoah G-38 weights in at hefty 4.5 lbs and looks very much out of place whether exhaust up or exhaust down.

I am trying toconvert togasoline for all my airplanes and therefore I'm not interested in large glow (or especially) electric engines.

I've been trying to research optional gasoline engines for the Sea Master. I have a brand new VVRC 20cc engine, but am not sure if this would have enough power to fly this large seaplane.
Icompared HP ratingsand found VVRC 20cc is rated higher than the G-38, but then Iread other threads which state HP ratings are meaningless. Hence Iam baffled on where to turn.

I'd appreciateyour suggestions.

thanks
dave
I'm afraid if I buy much more RC stuff, my wife's eyeball rolling wiill become somewhat permanent.

Depends on some different factors. I have a 17lb 106" Super Cub on floats with a G26 and while it won't hover, it flies ok swinging a Falcon carbon 18x6W

OTOH I have a 89" SBach that weighs 17lbs and 3D's with a DLE 55

I think the G38 is the wrong engine for that. You want to keep it as light as possible and you would have to create a unique mount for it or any other "stand-off" type mounted engine. I would look for an engine with beam mounts so you can use a typical engine mount and that would make it easier to install plus you could use the original nacelle/cowl.

May want to look at something like the Evolution 33GX:
http://www.horizonhobby.com/products...ngine-EVOE33GX

Or the CRRC 26 or 40:
http://www.crrcpro.com/product_show.asp?id=229

Your VV20cc will never be able to swing the size prop the G38 can, match it in amount of thrust generated or it's mechanical longevity. Converting the G38 from magneto ignition to CDI can easily shave all of a pound of weight if you so desire.

The Sea Master was designed in the 80's for the G-38, Quadra 35. I have a Sea Master with a McCculough 35 with springstarter, much heavier than the G-38 and fly's awesome. I swing a 17X8 three blade with plenty of clearance. The plane hasn't flown in atleast 10 years due to lake access, but its a blast to fly. Mount the G-38 put a three bladed prop on it and trim the muffler stacks and you'll be just fine. Flying off water is that much fun. Good-Luck

Thanks for the input everyone. I think I'll proceed with the G-38 initially and buy the EI conversion package. Probably the most prudent way to start.thanks again, your comments are greatly appreciated.dave

I personally would stick with the magneto and put a spring starter on it. I love my G38 set up this way. Never lets me down.

There is some benefit to using the mag engine on a pylon mount. With the CDI, where are you going to mount the ignition where it wont get wet?

Yeah, this isn't the 80's anymore. Lot's of other engine options today that would work better than the G38. I have the 38 on some planes and it's a great engine....but like I said before, I would put something different on it. The ignition box mounting will be a challenge . On the Evolution the ignition is almost a third the size of a Rcexl or C&H and would fit inside the nacelle.  If you are going to use the 38 I'd leave it on mag ignition.

Yes, that's a good point.I bought a 42 percent kill switch almost a year ago for the magneto version, so the first attempts will be just as it is now. Still visually not appealing, but with my old eyes, once airborne, I'll never notice. ;-)dave