The UMS 7-90 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
- 90cc 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 7-90
7-90CC 7CYLINDER TECHNICAL SPECIFICATION
| Standard | Metric | |
|---|---|---|
| Type | 4-Stroke Petrol | SPARK IGNITION |
| CYLINDER | 7 (ABC TYPE) | 7 (ABC TYPE) |
| CAPACITY (CU. IN) | 5.5 | 90CC |
| Bore | 0.98″ | 25.1MM |
| Stroke | 1.02″ | 26MM |
| Thrust* | 20.9lbf @ 24×10 Menz prop. | 9.5kgf @ 24×10 Menz prop. |
| Power (HP) | 6 | 6 |
| Rotation (RPM) | 1000 – 6000 | 1000 – 6000 |
| Weight | 6.1lbs | 2.8kg incl.(silencer ) |
| Engine Diameter | 9″ | 230MM |
| Engine Length | 6.7″ | 170MM |
| Propeller** | 24×8, 24×10, 24×12 | 24×8, 24×10, 24×12 |
| Muffler Type | Collector Ring | Collector Ring |
| Plug Type | 1/4-32 RcExl | 1/4-32 RcExl |
| Carburetor | WALBRO WT-621 | WALBRO WT-621 |
Brian Smith –
I have this radial on a Waco biplane and it flies very good 24-10 prop and vogelsang fuel pump . This engine runs and sounds like the real thing very happy with its performance .
Jim Allmon (verified owner) –
I am still in the break-in process on my UMS 7-90cc gas radial engine and already, I cannot be happier. Adrian is very quick to ship and offers extraordinary customer support that is second to none. These engines start easily and run fantastic, and the sound is simply awesome. I’m using a Biela 3 blade 22 x 12 with no external pump at the moment. I may order a pump at some point though, depending on the need.