RCGF 40cc Twin Cylinder Gasoline Engine: Part Two – The Flight Report


Well, I hate to say it, but the spring of 2018 will probably go down as the worst spring in history for RC flying weather! Between the wind, cold temperatures, and the rain, we had almost no good weather until the end of June to get out and fly. I was also out of the country visiting Seagull Models the last week of June, so I finally got the RCGF 40cc Twin Cylinder in the air at the beginning of July. We finally had our first really good week of flying weather, so my buddy Jim Buzzeo and I were off to the field as quickly as possible! For those of you that remember part one of this article, it went over my initial thoughts of the engine and installation. For the review, I’m using the Great Planes Avistar 30cc ARF – this airplane makes a great test bed for trying new equipment!

If you’d like to go back and check out part one of the RCGF 40cc engine review, you can find it here:   www.rcuniverse.com/articles/review/rcgf-40cc-twin-cylinder-gasoline-engine-part-1

Well, let’s get going here – I don’t want to make you guys wait any longer…

Photo Shoot

The standoffs I used are not the ones included with the engine – These are custom cut to the length I needed for installing a cowl. As it turned out, there wouldn’t be much cowl left after cutting around the cylinder heads and mufflers, so I purchase a small sheet of clear acrylic to install and keep the Monokote stuck to the nose of the Avistar 30cc.

Flight Report

As I stated in the intro, it was a bad spring for flying weather. But, I got the RCGF and Avistar charged up and ready at the first sign of a decent day at our local field. As it turned out, it was an awesome Saturday afternoon – 84° F, a mostly sunny sky with just a few wafty clouds, and a slight breeze from the East. It couldn’t have been much better of a day, if you ask me!

I filled the tank with a 30:1 mix of 91 Octan, non-ethanol, premium gas and synthetic oil, powered up my Futaba 16SZ transmitter (The review for the transmitter can be found here:  www.rcuniverse.com/articles/review/futaba-16sz-radio-system) and the receiver and ignition on the Avistar 30cc.

For the first start of the day, I like to use my trusty cordless starter, as it draws fuel to the carburetor much quicker than hand propping. At this point, the RCGF 40cc twin had been sitting since October of 2017 when it was last run, but the starter made quick work of getting fuel into the carburetor. The engine popped and coughed, so I opened the choke and spun the engine with the starter again. The 40cc twin came to life approximately two seconds later, and was running quite nicely. I bumped the idle up a couple of notches with the digital trim switch on my 16SZ, and let the engine warm up for about a minute.

The cylinders were up to operating temperature at that point, so I opened up the throttle to check the transition and high end operation. All were a ‘Go’, so the Avistar 30cc was taxied out to the runway.

The throttle was advanced, and the RCGF 40cc twin revved up quickly with the Falcon 19×10 Beechwood propeller. The Avistar rolled easily down the runway and took off effortlessly! With the throttle set to just less than three-quarters, the twin cylinder engine had more than enough power to pull the giant scale trainer around. A few circuits were done around our field, including a couple of full-throttle passes. The RCGF 40 pulled HARD at full throttle, moving the Avistar very quickly across the sky!

Pulling back the left stick to just above idle, we tested the low speed operation. Even just above idle, the 40cc twin had enough pull to keep the Avistar flying without fear of a stall. Adding power again proved easy with no sputtering, so I knew the needles were set correctly.

As the Avistar was coming around to land, Jim pulled the throttle back a little too late – the Avistar floats very well, and was about to run out of room to land, so a go-around was in order. Jim pushed the stick forward, and the engine picked up speed easily! pulling back earlier proved to work on the second landing attempt, and the Avistar settled in nicely after a little bounce. That was it – the engine ran as perfectly as I had expected it to run!

Check out my video to see the RCGF 40cc Twin Cylinder in action!


So far, I have been very please with every one of my RCGF engines. I have the 10cc, a pair of 15cc, a 20cc side exhaust, the 21cc twin cylinder, the 35cc rear exhaust, the 60cc rear exhaust, the 60cc twin cylinder, the 70cc twin cylinder, and the 120cc twin cylinder. All of them run great, and I can now add the 40cc twin to that list as well! This 40cc twin is a little powerhouse, and will give any 30cc aircraft just a little boost above your average 30cc single cylinder engine. Add to that the throaty sound coming from two mufflers, and you’re bound to like this engine as much as I do! Well done, RCGF, well done. That’s all for now from my shop and flying field – we’ll see you next time. -GB

Contact Information

RCGF Engines:   www.rcgfusa.com

Great Planes:  www.greatplanes.com

Pacer/Zap Adhesives:   www.franktiano.com

Falcon Propellers:   www.justmodelprops.com

DuBro:   www.dubro.com

Futaba:   www.futabarc.com

Tower Hobbies:   www.towerhobbies.com

Futaba USA (Coming Soon):   futabausa.com


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