It seems as though there’s a lot of competition in the gas engine market these days, and there are a few names that everyone is familiar with. Some of the big ones are DA, DLE, and 3W – just to name a few. There’s more to the gas engine game than just them! Over the past decade, several smaller companies have sprung up – some have stayed, and some have gone away. But, just because these smaller companies may not be as well known, doesn’t mean they don’t have good products at good prices!
RCGF, a Chinese manufacturer of gasoline engines, designs and manufactures engines specifically for the RC aircraft market. They have a line of gas engines as small as 15cc, all the way up to 120cc! In addition to the vast size range, RCGF has a number of twin-cylinder engines as well – 30, 40, 60, and 120cc – all are a ‘boxer’ type, meaning the pistons travel in opposite directions to minimize load and balance concerns. This, in turn, also reduces vibration.
I first laid eyes on the 30cc twin at the Toledo Expo, in April, and I decided that I NEEDED to have one – as it turned out, I really did NEED one mid-summer! So, after a few emails with RCGF’s sales team, I had a new 30cc twin delivered to my front door step.
Without wasting any more time, let’s get the box on the table and see what’s inside!
Price: $399.99 (Accurate at time of review)
Engine Type: 2 Stroke Gasoline Engine
Cylinder Displacement: 30cc (1.83 ci)
Weight with Ignition and Mufflers: 1180g
Weight w/o Ignition and Mufflers: 900g
Bore x Stroke: 32mm x 19.6mm (1.26 in x .77 in)
Carburetor: Walbro-type designed by RCGF
Ignition: DC-CDI (Computer Controlled, Auto Advance, Electronic Ignition System)
Power Supply: 4.8 – 6 Volts
Speed Range: 1500-8500 RPM
Recommended Fuel Ratio: 30:1 (ashless 2-stroke oil)
Recommended Propellers: 18×8 – 19×8 Two Blade
- Specifically Designed for RC Use
- One Year Limited Warranty
- ‘Boxer’ Design Reduces Vibration
- Double Rings on Pistons
- Narrow over-all Width
- Walbro-style Pumped Carburetor
- Lightweight Ignition Module
- Standoffs and Radial Engine Mount Included
- Spark Plugs Needed to Be Replaced – See Text
- Minor Exhaust Leak on One Muffler – See Text
Time Required to Build:
My engine was shipped directly from the factory in China, so it was double-boxed. Opening the shipping box revealed a full-color box with plenty of foam padding inside to protect the engine. Additionally, the engine and its various components were individually bagged. With everything inventoried and laid out on the table, I realized that there were a lot of parts!
A quick inspection of the engine itself revealed some very nice casting and machining work, and the parts fit looked great! The included radial engine mount appeared lightweight but sturdy. Also included were four 20mm standoffs, and mounting hardware. The Walbro-style pumped carburetor was positioned for easy throttle linkage connections. I briefly removed the pump diaphragm cover and inspected the fuel screen for manufacturing debris – it was clean, so the carburetor was reassembled!
Now here’s something I hadn’t seen before. RCGF included TWO propeller nuts – A locking nut and prop washer AND a threaded prop nut for installing a spinner! The twin cylinder ignition system looked good, and accepts a 4.8 – 6 Volt power supply. The included can mufflers were very lightweight, and appeared to be manufactured well.
Though the manual is not engine specific, it does a great job of covering all the basics – from which oil to use and how to perform the ‘break-in’ procedure to helpful tips on troubleshooting and safety. The manual I received was in full color as well!
Because I’m using an airplane that had a different engine mounted previously, some of what I will be doing may not apply to your specific installation.
Installation began with measuring the distance from the firewall to the outside of the cowl – In this particular installation, the distance was 135mm. I added 6mm to the 135mm to allow clearance for the spinner back-plate. The dimension from the engine mount to the prop hub, on the 30cc twin-cylinder is 110mm. With a total distance of 141mm in mind, I removed the cowl and old hardware.
With the firewall now cleared of the old hardware, I had some large holes and minor damage to repair – this was a perfect time to strengthen the firewall! I cut two pieces of light ply to fit the existing firewall. The ply pieces I used just happened to be 5mm thick, so in addition to strengthening the firewall, they added 10mm to the front of the firewall. The two lines on the ply mark the center of the prop shaft, while the arrow and the ‘F’ designate the front and top of the new firewall. I made a template from the engine mount dimensions, drilled bolt holes in the new firewall, and installed four 70x5mm bolts and washers from the back side of the firewall.
Since the total dimension I needed was 141 mm, I added a 1mm washer behind each of the 20mm standoffs. This, in addition to the 10mm of new firewall, will put the prop hub exactly where I wanted it. The engine was slid on to the four bolts, followed by another washer and a nut. The bolts and nuts included with the engine are 5mm in diameter, so I was able to use the nuts with the longer bolts required for this particular installation. I did add a few drops of Pacer thread locking compound (available through ZAP Adhesives) to each of the four nuts because they are not locking nuts.
Next came the ignition module. The spark plug cables are more than long enough for any typical installation, which made it easy to mount the module. The excess cable was secured to the airframe with zip-ties. I also attached the fuel line to the carburetor, making sure to mount the fuel line in a location away from where the muffler will later be mounted.
The ignition module was secured to the airframe using zip-ties. A piece of dense foam was placed between the module and the airframe, to reduce vibration. The battery and signal wires were then connected and secured using the included locking clips and a few zip-ties. With the engine installation completed, I installed the two mufflers, a brand new Falcon propeller, and a DuBro plastic spinner.
Time to head to the field to fire up the engine!
Falcon Propellers and Bob’s Hobby Center at Steve’s Hangar
Bob’s Hobby Center at Steve’s Hangar is the US distributor for Falcon Propellers. They offer a full product range – i.e. gas wood props, electric wood props, carbon spinners for gas and electric applications, and carbon fiber props for both gas and electric. At the 2014 Extreme Flight Challenge, 13 out of the 15 competitors flew Falcon Props!
As well as being the US distributor for Falcon and Xoar, Bob’s Hobby Center is a great, full-line hobby store with knowledgeable, helpful employees. If you’re in Orlando, Florida, stop in at Bob’s – you’ll be glad you did! You can also find Bob’s Hobby Center on the web. If you’re looking for a full line of high quality propellers, look no further than FALCON PROPS!
With my Redwing RC MX2 securely tied to a starting bench, I filled the fuel tank with 30:1 pre-mixed gas and closed the carburetor’s choke. As this was a brand new engine, I decided to use my heavy-duty electric starter to get the twin started. With the choke closed, I spun the engine with the starter for approximately three seconds, and it momentarily started. I then opened the choke and spun the engine, again, with the starter – another two to three seconds and the 30cc twin came to life!
Reviewer’s Note: It became apparent, rather quickly, that the muffler on the left cylinder had a leak where the pipe joined to the main cannister. After speaking with the sales team at RCGF, they offered to replace the muffler at no charge. I thanked them kindly for the offer, but chose to have my muffler welded at a local machine shop.
Per the manual, I set the throttle servo to keep the engine running at approximately 2500 RPM, and let it run. The MX2 has a small fuel tank, so I had to run the engine in two sessions, for a total of 40 minutes. With the second tank gone, I filled the tank and started the engine. As I was running the throttle up and down, I could hear that the engine did not sound right above half throttle – one of the cylinders was not firing. After a brief discussion amongst my fellow club members, we started troubleshooting the concern. As it turned out, one of the included spark plugs was not firing at higher RPMs. I replaced the spark plugs with a pair of NGK CM-6 spark plugs, and fired up the engine.
As I stated before, the engine ran fine on the included spark plugs up to half throttle. The first time I ran up the engine with the new spark plugs I was impressed! The 30cc really came to life! With an 18×6 Falcon prop, I was seeing 7900 – 8000RPM at full throttle!
Editor’s Note: After talking with RCGF about the concern I had with the spark plugs, they informed me that they will soon be including genuine NGK plugs with all United States bound engines.
Though I had run the engine through double the minimum recommended break-in time period, I left the needles set to a rich running condition – even still the twin had PLENTY of power! Now that it was running reliably, it was time to get the engine (and MX2) airborne. The MX2 was taxied out onto the runway and I slowly advanced the throttle. The 19×8 Falcon prop I installed after the initial runs was grabbing fiercely at the air and pulling the MX2 up and away! Most of the time, I was flying with the throttle just above half, and that was more than enough power for the ten-pound airplane!
Even with the needles set rich, I never felt as if the engine was going to quit – yes, it did cough and sputter a couple of times, but that’s pretty normal running an engine on the rich side of the needles. I set up for my landing feeling confident that the 30cc twin would stay running, and it did – right up until I shut it down at the end of my flight!
By the fourth tank of fuel (approximately 60 minutes of previous running time) I was able to hand start the engine both cold and after running – the twin was just a little too tight to easily hand start when brand new, but even just an hour of run-time made a BIG difference! Just imagine what this engine will perform like after a couple of GALLONS of fuel!
Final thoughts on the new RCGF 30cc twin-cylinder: I love the looks of this engine – the casting and machining are high quality without flaws. I love the sound: The two mufflers have a different sound than a single 30cc sized engine – the crackle and general tone are a higher pitch, but still sound really cool! I love the ease of use and comfort level: Break in was short and simple, and after the spark plug change, the engine ran very reliably! I think that the new 30cc twin-cylinder from RCGF is a great little engine! One other note I’d like to add – the sales team at RCGF told me that they are in the process of building an RCGF authorized service center in the United States – even the best engines sometimes need a little work, and now it can be done right here in the US!
167,Renmin North Road
Bob’s Hobby Center
540 N Goldenrod Rd
Orlando, FL 32807
Phone: (407) 277-1248
Frank Tiano Enterprises
3607 Ventura Drive E.
Lakeland, Florida 33811
Du-Bro Products, Inc
P.O. Box 815
480 Bonner Rd
Wauconda, IL 60084
Order or Stock Status:
General HelpWith Plane or Parts Selection:
Place an Order on the Phone:
2904 Research Rd
Champaign, IL 61822