RCGF USA’s 20RE Rear-Exhaust Engine

Enjoy a glance again at our evaluate of the RCGF 20cc rear exhaust engine!

The RCGF rear exhaust (20RE) is a brand new 20cc gasoline engine simply added to the RCGF USA line. It is a rear-intake/rear-exhaust design, and it has side-mounting tabs just like RC glow engines. the engine options digital ignition and so eliminates the heavy flywheel used for magneto-driven engines. And having each the carburetor and muffler situated aft of the cylinder head, it makes for a really slim set up footprint. Being such a compact engine, the 20RE is right for any sport or scale airplane within the .90 to 1.20 engine vary, and a few guys are even getting these engines shoehorned into .50- to .60-size warbird ARF racers.

Located in Sierra Vista, Arizona, RCGF USA is the factory-authorized and factory-supplied service middle for the United States. Joe and Patti Nelson take delight in supplying actual factory-spec RCGF engines, which they test-run individually earlier than delivery to their clients. They additionally provide fast elements availability for restore, with quick turnaround occasions anyplace within the continental United States.

UNIQUE FEATURES

As talked about, the engine has digital ignition, and the RCGF DC-CDI module options auto-advance for simpler beginning and easy throttle response. The energy necessities for the ignition module are from 4.8 to eight.4 volts, which makes compact 2S 7.4V LiPo or 6.6V A123 packs good decisions. A minimal of 800mAh is advisable for powering the engine’s ignition system. The module case is compact with no attachment tabs, so the case must be wrapped in foam for defense. It includes a metal-shielded spark-plug lead and a steel spark-plug cap with a locking ring for safe attachment. Also included are security clips for the battery, and sensor wire connectors and spiral wire protectors for the wire leads. There are three leads coming from the module: one is for the battery pack (black and crimson leads), one other for the ignition sensor (with the feminine connector), and the third to be used with telemetry or a Pegasus tachometer. (Do not connect a battery pack to the latter lead as it’s going to injury the module.) All of the connectors are Futaba sort.

Overall, the match and end of the 20RE is superb with a high-quality floor therapy. The engine comes with two composite engine mounts to safe the engine to the firewall; a muffler; a spark plug; required machine bolts; a steel warmth protect that goes between the engine and the muffler for correct cooling; an exhaust gasket; and all required nuts, bolts, and washers. There can also be a big locking prop nut in addition to an prolonged prop nut with a threaded middle to be used with spinners. The carburetor is a typical pumper sort, which makes use of piston pulse stress to drive its diaphragm. It is provided with a choke and a spring-loaded throttle butterfly valve. The accent package deal comes with an prolonged steel throttle arm, which may change the economic throttle arm. I used brass Du-Bro E/Z Connectors (dubro.com) and a size of skinny music wire for my throttle linkage.

Internally, the engine has an aluminum piston with a single metal ring connected to the connecting rod with a needle-bearing supported wristpin. The wristpin is secured in place with two wire E-clips. The crankshaft has twin (entrance and rear) bearings for assist, and the prop hub is ready up with a threaded propeller attachment with a security nut and prop washer. Gaskets seal each the cylinder head and the backplate to the engine case. Two gaskets and a molded plastic isolator block protect the carburetor from extra engine warmth. Four bolts safe the cylinder head, whereas three maintain the backplate in place.

The carburetor is a typical pumper sort, and it’s outfitted with a choke. The throttle arm is spring loaded to the closed place.

Equipped with an digital ignition system, the engine has a magnet imbedded within the propeller hub that triggers the Hall impact sensor connected to the entrance of the engine case.

ENGINE SETUP

Before firing up any gasoline engine, the very first thing required is a correct set up of the gasoline system, with an inline gasoline filter put in between the engine and gasoline tank. For the evaluate, I merely connected the engine to my take a look at rig in order that I might get to every part simply whereas making changes. Joe at all times says that you need to first begin the engine with the manufacturing unit settings and solely after that ought to you attempt making changes to the carburetor. He test-runs each engine he ships. I additionally used a heavy-duty ignition swap and a completely charged ignition battery pack.

As with most gasoline engines, there is no such thing as a particular engine break-in required, however it’s endorsed to do your first few runs with common 90-octane gasoline combined with high-quality petroleum-based two-cycle oil at a 30:1 ratio. Run the engine for about 20 minutes at about 2,500rpm utilizing a barely smaller prop than the dimensions you propose to fly with. If you do that with the engine mounted to your airplane, take away the cowling for extra engine cooling. The correct run-in interval for the engine is about 2 gallons after which you’ll be able to swap to a gasoline mixture of about 50:1. At this time, the high-and low-end needles might should be fine-tuned for optimum efficiency—simply keep in mind to begin with the manufacturing unit settings from the beginning.

RCGF USA provides propellers, and the advisable prop sizes are 16×6 and 16×8. I discovered that the RCGF props didn’t require any adjustment to stability correctly, however at all times examine your propellers with a high quality prop balancer to attenuate engine vibration.

Here are a few of the equipment included with the engine. Hardware can also be included.

STARTING THE ENGINE

For this evaluate, I used a number of propellers, every checked for correct stability with my Du-Bro balancer. Starting the engine may be very straightforward. Open the throttle absolutely, shut the choke, and flip the propeller over till you see gasoline flowing by the gasoline line and into the carburetor. Switch on the ignition system, and proceed flipping the prop till you hear the engine “cough,” indicating that the engine is correctly primed. Now open the choke, deliver the throttle to about quarter throttle, and flip the prop a couple of extra occasions. After about 4 or 5 flips, the engine ought to hearth up and settle right into a easy idle. For security, we suggest utilizing a Sullivan Products electrical starter (sullivanproducts.com). While operating engines on my take a look at stand, I take advantage of a servo and a spare receiver to regulate the throttle with my transmitter. Allow the engine to heat up for a couple of minutes earlier than advancing the throttle.

After operating about 10 oz. of gasoline by the brand new 20RE, it ran easily, with a gradual transition from idle to full energy. Throughout the take a look at run, utilizing the assorted propellers talked about, I didn’t really feel the necessity to alter the needle valves—simply as Joe had advised. After operating a gallon or two by the engine, you may have the ability to tweak the carburetor settings barely to achieve just a little extra on the highest finish, however from the beginning, the idle was very stable.

Like all RCGF USA engines, the 20RE has high quality internals like this aluminum single-ring piston and metal ring, wristpin, solid connecting rod, E-clips, and higher needle bearings. Needle bearings additionally assist the decrease finish of the conrod.

BOTTOM LINE

If you’re searching for a easy, easy-to begin 20cc gasoline engine to your subsequent sport flier or scale mission, I’d extremely suggest the brand new 20RE from RCGF USA. It is effectively constructed, has stable efficiency, and is backed with glorious customer support. Priced at $229.99, the 20RE is a wonderful worth.

Shown right here operating on the creator’s take a look at rig, the engine is straightforward to begin and is comparatively quiet for a 20cc-size gasoline engine. The muffler may be very efficient.

PROPELLER PERFORMANCE

The RCGF propellers proven right here required no balancing.

Running the engine on my take a look at rig, I used to be in a position to run a couple of propellers, and I recorded the rpms for the highest finish and for idle settings. I used a Du-Bro 20-oz. gasoline tank with gasoline-compatible gasoline line and tank stopper. I used a RCGF, Falcon (falconpropellers.com), APC (apcprop.com), and Master Airscrew (masterairscrew.com) composite propellers, every balanced with my Du-Bro balancer earlier than every take a look at run.

Brand	Size	Type	Max rpm	Idle rpm	Sound degree (db)
RCGF	16×8	Wood	7,300	2,100	80.1
RCGF	16×6	Wood	7,500	2,000	82.3
Falcon	16×8	Wood	7,450	1,900	84.2
Falcon	16×6	Wood	7,600	2,000	82.5
APC	15×8	Composite	7,600	1,900	79.5
APC	15×6	Composite	7,700	1,950	78.3
Master Airscrew	16×8	Composite	7,700	1,800	81.4