I have an OS 55ax in an Aeroworks Pro260x profile. I hate glow and the engine has been nothing but a pain since new. I have looked at replacing it with a 10cc gasser like the Evolution or RCGF. The weight including the ignition of the RCGF is almost the same as the OS 55. How reliable are these smaller gas engines? I like that the RCGF has a version with a walbro type carb but no one at my field is running anything smaller than 20cc.

My flying bud has the 8cc evolution gas engine and it actually runs pretty good but it may be a little underpowered i think its equal to a .50 glow... My .55AX runs perfect.. Is yours good a broke in? Gas is much cheaper and cleaner tho.. I personally have the OS 15cc gasser with ign. It ran good for a couple months and then i had sum problems with it.. OS also makes the 10cc glow gasser but one of the reviews said the idle is high all the time and its hard to slow down for landings and taxiing... Hope this helps

i put an Aeroworks Pro260x profile with an OS 15GGT for a flying buddy a couple years back. perfect combination...... motor isn't even close to cheap as he paid close to $500' after taxes at the time...
D.

I have been running an RCGF 10cc for about a year now on a 46 size FW190 and it runs like a swiss watch and makes great power. A friend of mine had the Evolution and was not thrilled with the performance on a rather light MOJO40. In my experience the RCGF out performs the Evolution motor by far and turns a bigger prop too. I wouldn't hesitate to buy another one.

I did some thrust tests on the RCGF and originally went with a MAS 13x8 -
I'm currently using a TF wooden 14x8 cut down to 13.5x8 right now, I never measured thrust for it, but with a tweak of the carb for the lighter prop, it performs similar to the MAS 13x8 in the air with a faster spool up

Prop - Idle RPM - Max RPM - Thrust in Ounces
MAS 13x8 - 1750 - 8100 - 104.3
APC 13x8 - 1900 - 8700 - 101.2
MAS 14x8 - 1600 - 7100 - 100.7
APC 14x6 - 1600 - 8000 - 105.4

I've spent a lot of time with the 10cc Evo engine, both the original and the newer version with pump built into the carb. I think the engine makes great power, turning an APC 13x6 to 10.5k easily (crazy power on a 5 lb. airframe). The problem I got into with them is when looking for precision throttle control. There's flat spots everywhere, or right where I didn't want them anyway. I'm sure these wouldn't be that big a deal for sport flying (maybe not even noticeable), but for the precision throttling required trying to hover or even when in high alpha, it seemed like I was always chasing perfection. That's my impression anyway. FWIW, -Al

Originally Posted by GScott

I have an OS 55ax in an Aeroworks Pro260x profile. I hate glow and the engine has been nothing but a pain since new. I have looked at replacing it with a 10cc gasser like the Evolution or RCGF. The weight including the ignition of the RCGF is almost the same as the OS 55. How reliable are these smaller gas engines? I like that the RCGF has a version with a walbro type carb but no one at my field is running anything smaller than 20cc.

IMHO you would be better off finding a profile big enough for a 30cc gasser. Gasoline engines smaller than 30cc tend to be heavy for the amount of power they produce, and less reliable. Plus, 30cc and bigger airplanes just fly much more smoothly. If you have a real need to fly small airplanes, better to power them with electric.

Originally Posted by Low_Cal

IMHO you would be better off finding a profile big enough for a 30cc gasser. Gasoline engines smaller than 30cc tend to be heavy for the amount of power they produce, and less reliable. Plus, 30cc and bigger airplanes just fly much more smoothly. If you have a real need to fly small airplanes, better to power them with electric.

I tend to agree with most of the above but I would move the bar down to 20cc rather than 30. I would be hard pressed to find any faults with my DLE 20 as it produces excellent power and is as reliable and easy handling as any of my larger gassers.

There might be some 15cc engines out there that fit the same mold but under 20cc, I'm thinking a glo engine or electric is a better choice. There are some really excellent glo engines available with the mess and fuel costs being their only down side.

Agree with Truckracer. The 20's (DLE, RCGF, and ValleyView, take your pick) represent a power to weight package that's pretty tough to beat and are in a class pretty much to themselves. There are 20cc profiles available (as well as fatties) that offer pretty much unlimited 3D, even though the bigger stuff will still outclass them. The 3 20's mentioned will start and handle every bit as easily as the 30cc and bigger engines will.

All that said, though smaller gassers exist ( sub 20cc), I haven't experienced or seen one I'd recommend for 3D work. Sport yes, but not 3D.

Also, regarding the smaller gassers, I think one of the reasons people may hear about issues with them is that first time gassers are drawn to them when getting their feet wet, due to lower costs (engines AND air frames). The issues they run into while on the learning curve most of us went through early on are often widely publicized - possibly creating some undeserved doubt regarding engine reliability.... For instance - how many times do you read about an issue very likely related to a new engine with a dry carb in the 50cc+ sizes?

I agree, so many first time gasser users are attracted to the smaller gassers. Nothing against them as a group but most just don't have the experience operating any gasser and when a problem comes up, too often the engine gets blamed for the problem. They would probably have the same problem or other problems with any gasser regardless of size until they acquire a higher experience level.

We've all been there before and just goes with the territory when learning something new.

Originally Posted by AHicks

All that said, though smaller gassers exist ( sub 20cc), I haven't experienced or seen one I'd recommend for 3D work. Sport yes, but not 3D.

Also, regarding the smaller gassers, I think one of the reasons people may hear about issues with them is that first time gassers are drawn to them when getting their feet wet, due to lower costs (engines AND air frames). The issues they run into while on the learning curve most of us went through early on are often widely publicized - possibly creating some undeserved doubt regarding engine reliability.... For instance - how many times do you read about an issue very likely related to a new engine with a dry carb in the 50cc+ sizes?

I agree with that too... Electric will be far superior to a gas engine in smaller 3D airframes.

I have many years experience with gassers so the little one's don't give me any fits for the most part. Not all of them have a choke, so the first start of the day can be a bear, but in general, they are just as reliable as any nitro engine, if not more. I don't fly nitro as a general rule and I get tired of charging after only 5-10 mins in the air with the 40-60 size electrics, so every time I have a chance to build a small gasser warbird or sport plane I go for it.

I put an Evolution 20 into a Top Flite .60 P-47 and wished I didn't. The guy at the LHS talked this thing up to be the greatest thing since sliced bread...yeah, not so much. It's hard to start, is extremely underpowered for its class and does not have a linear throttle transition what so ever. You get idle, low and WFO!

I now wish I had gone with something else other than an Evolution. I've used their glow engines in the past and really liked them. I think they've got some work to do in the gasser market.

Well I bit the bullet. For over 4 years my 72" trainer has set in the corner because I went giant scale gas. Absolutely refuse to fly glow any longer. And electric is just not for me. So I waited and this perfectly new trainer has set. Now RCGF has the updated 10cc gasser with the full carb. Bought one and showed up yesterday. Since I have four grandsons and a few student pilots, now is a good time to try tgat lil guy out. Heck, might even enjoy shooting touch and go's and just doing some no frills flying. I'll post my results in a few days.

Originally Posted by infernorcteam

I put an Evolution 20 into a Top Flite .60 P-47 and wished I didn't. The guy at the LHS talked this thing up to be the greatest thing since sliced bread...yeah, not so much. It's hard to start, is extremely underpowered for its class and does not have a linear throttle transition what so ever. You get idle, low and WFO!

I now wish I had gone with something else other than an Evolution. I've used their glow engines in the past and really liked them. I think they've got some work to do in the gasser market.

I'm guessing the Evolution 20 is not the best 20 on the market . . .

I've had a chance to run the RCGF 10cc a few times. All I can say is, it is quite the impressive little engine. It is hard for me to find any warm fuzzies for an engine smaller than what I normally fly. But in an attempt to get a plane ready to teach my grandsons and other student pilots to fly, I chose the RCGF 10cc. I really like this little guy. Draws fuel immediately, starts easy, runs fantastic and puts out a lot of power for its size. 9610 rpm (APC 12x8)