Heli-NuBee

My Phoenix Ryan STA is almost ready for its maiden flights now. Phoenix Ryan STA, Evolution 20 CC Gas engine, J-Tec muffler (note: the stock pitts style muffler that comes with the engine would not fit this plane), 16 oz tank, 15x8 prop, weighs in at 9-1/2 lbs full of fuel.



Best wishes and good safe flying.

Heli-NuBee (AKA Roger the radial rabbit)

blackdablack

Would the 20cc be a good fit for a Pulse 125? What would the prop size be?

allans

My Feedback: (11)

Yes I think so. I would follow the engine manufactures recommendation as to prop size and the type of flying you do.

josephcraig

I traded evo 15gxv1 last year and regretted it since.I bought 15gx2 this year and I think its even better.No need to choke engine when using electric starter.After 2 gallons of fuel it has really come around.Pete and Jimmy like apc blades,but I really like the vess 14 x 6 props.Seem to be sweet spot for it in my opinion.May have to try 20gx2 later on.I don't know how much the pulse 125 weighs,but if its over 9 to 10 lbs,I would say it would be a load for the 20gx.My calculation on my 15 is maybe 9 to 10 lbs of thrust,so 20 should do at least 12 to 13 range.20cc on 60-90 size plane would be sweeter.8-9lb plane.

lvsloan1

I'm not too keen on the Evolution engine yet. I bought a used 10cc and it runs extremely hot to the point of melting the yellow tygon tubing off the muffler pressure tap even when I run it so rich it's 4 cycling?? The manual on this engine says to mix the gas/oil at 20:1 so maybe I should go to 32:1? Also, does the Neoprene Fuel Tubing redistribute heat more than the yellow tygon? Thanks! I may have to sell this engine and go nitro if I'm ever going to fly again. LOL!

Truckracer

My Feedback: (19)

Melting Tygon line is not an indication of the engine running too hot as yellow Tygon melts at a very low temperature. You could use a section of black Viton line on the mufler and it will not be prone to melt as it tolerates much higher temperatures.

I'm not saying the engine is a good or bad one, just that the melting line is not an indicator of how the engine is running.

lvsloan1

Awesome! Thanks for the knowledge as I'm just getting back into flying after 30 years. Wanted to go gas because of the lower cost of fuel but still worried about the bad vibration since I now know what fuel tubing to use. I couldn't find Hayes neoprene at Tower so I ordered the Dubrovnik neoprene to try. Thanks!

Truckracer

My Feedback: (19)

Neoprene won't tolerate as much heat as Viton. In a pinch, you could use a short section of regular glo silicone tubing on the muffler but it will degrade quickly in the presence of gasoline. It will probably last for one outing though. Another line to consider is the blue Fluorosilicone line that McMaster Carr, an industrial supplier handles. It is recommended for gasoline and tolerates heat very well. Be advised, both Viton and Fluorosilicone are quite expensive but they do the job expected of them in the conditions they have to work in.

lvsloan1

Thanks again for your help! I know some friends in other areas that use neoprene on their muffler pressure taps with no problems but don't think they fly gas engines, only nitro. On disability so can't afford high prices to get flying again. LOL!

pilotpete2

While you can't use silicone tubibg on the gas lines, you CAN use it on the vent line/muffler tap with a gas engine. In fact its the only thing that will work well. The key is that any exposure to gasoline is for very short duration..

I have an early example of the EVO 15cc gasser. I fought the problem with Tygon melting and Viton splitting at the muffler tap. I then tried joining a short piece of silicone glow fuel line about an inch from the muffler and that held up fine. The next season I put the Evo in a new plane and re-plumbed the tank using silicone from the tank to the muffler. I thought I'd have replace it after a season, well after three seasons, the silicone vent line is in perfect condition. FWIW, the tubing is Dubro silicone.
All I can say is , it works!
Pete

Truckracer

My Feedback: (19)

Pete, I certainly wouldn't argue with success. Sometimes you just have to try and see what works.

I use silicone exhaust extensions on gasser mufflers and the tubing doesn't degrade at all. About my only complaint is the exhaust residue sticks to the inside of the tubing and comes out in sticky clumps rather than just spraying out into the air and disappearing as it would with metal or Teflon. Still not like glo exhaust residue though.

lvsloan1

Thank you for this info. I'm trying all of these suggestions to see what works best.

pilotpete2

Yeah, I never thought it would last over a season.

Well now, the word is out. Don't ever fly too close on Truckracer's six. You will get slimed!!!!!
Pete

Truckracer

My Feedback: (19)

Na, not slimed but maybe a black splotch or two. Splat, splat. Change back to a different extension and the exhaust residue goes back to normal.

the Wasp

My Feedback: (1)

can some one accurately measure for me the 20GX Carburetor Barrel's I.D.,, and also the Carburetor's O.D. were it mounts in the Crank Case,

I have a Magnum 180 4St and I would like to try the 20GX carb on it

thanks guys
Jim