The UMS 7-50 is a very reliable radial engines which uses gas as fuel. UMS has a ton of experience building radial engines. It has brought more than 2000 engines to market so far. The design and construction are upper class leading to a outstanding realibility of these engines. They are easily servicebale. All critical parts are easily accessible.
- 7 cylinder radial configuration absolutely stunning looks and realism
- 50cc displacement perfect for scale project
- Comes complete with exhaust collector ring,spark plugs,electronic ignition, and engine mount ready to run
- User-friendly choke and throttle bell cranks included makes installation and operation easy
- Made from aluminum or bar stock where appropriate and CNC-machined accurate and repeatable specifications each and every time
- Cylinder head and crankcases produced from aircraft grade alloys
- Heavy duty double bearing crankshaft
- Billet aluminum pistons and hardened steel rings
- Hard chromed and lapped cylinder bores
- Hardened steel cams
- Burns 87-110 octane gasoline with 32:1 gas/oil mixture
Specifications
UMS Gas Radial Engine Manual 7-50
| Standard | Metric | |
|---|---|---|
| Type | 4-Stroke Petrol | SPARK IGNITION |
| CYLINDER | 7 (ABC TYPE) | 7 (ABC TYPE) |
| CAPACITY (CU. IN) | 3 | 50CC |
| Bore | 0.79″ | 20.2MM |
| Stroke | 0.86″ | 22MM |
| Thrust* | 11lbf @ 20×8 Menz prop. | 5kgf @ 20×8 Menz prop. |
| Power (HP) | 3.3 | 3.3 |
| Rotation (RPM) | 1000 – 6300 | 1000 – 6300 |
| Weight | 3.7lbs | 1.7kg incl.(silencer ) |
| Engine Diameter | 7.3″ | 185MM |
| Engine Length | 5.7″ | 145MM |
| Propeller** | 17×10, 18×12, 20×8 | 17×10, 18×12, 20×8 |
| Muffler Type | Collector Ring | Collector Ring |
| Plug Type | 1/4-32 RcExl | 1/4-32 RcExl |
| Carburetor | UMS | UMS |
Rich –
Motor just doesn’t put out any power. Installed carb conversion kit…not much help. Tried it in a Phoenix Stinson and a Seagull Gee Bee….18 and 14.5 lbs respectively. Engine lacked power. It does look good though…😑
Chris Ross (verified owner) –
This is the first radial I’ve owned and I kept my optimism low based on the other review here and info on the forums. Well I can tell you this is a beautiful engine and mine ran perfect out of the box!! Turnigy 18X10 idle 1200-1500rpm & WOT 6300rpm. After a 1/2 gallon through it , not perfect. Four of the cylinders were not firing on the top end. It turned out the plugs were fouled, probably due to the heavy break-in sludge that has now subsided for the most part after almost 2 gallons through it. See it run https://youtu.be/QBet_BA9ffc . With the Master Airscrew classic 20X10 it’s pulling 12.12lbs of static thrust and idling as low as 900rpms. This should have no problem pulling my Phoenix 120 Corsair around which the 50cc was the only radial that will fit the cowl that I felt could fly it with authority.