91HZ-R 3C Speed Red Competition Heli Engine
Designed for precision aerobatics!
Following the popularity of the 91HZ-R with On-Demand Regulator, O.S. has now taken high-performance, high-speed helicopter engines to the next stage of evolution. Introducing the 91HZ-R Speed Engines - based on the 91HZ-R, factory-tuned at the O.S./Japan facilities and guaranteed to blow you away! The 3C version is designed expressly for F3C competition with its controlled, precise maneuvers in mind. For pilots who prefer aggressive, stick-bashing 3D flight competition, O.S. offers a 3D version.
Achieve faster flight speeds and improved hovering stability.
Features include:
- Lightweight, machined heatsink head
- Big-bore carburetors best-suited for the intended use (F3C or 3D)
- Best precision advanced exhaust cylinder timing (for F3C or 3D)
- Newly designed combustion chambers, shaped to match the big bore carburetors and advanced exhaust cylinder timing
- Lightweight, forged steel crankshaft counter weight to lower vibration for higher speeds
- Improved backplate shape, to accommodate Futaba's BPS-1 RPM Sensor and increase primary pressure for greater stability
- Specifications
- Parts Listing
- Accessories
- Gallery
Stock Number: OSMG1980
Displacement: 0.91 cu in (14.9 cc)
Bore: 1.09 in (27.7 mm)
Stroke: 0.98 in (24.8 mm)
Practical rpm: 2,000-16,500
Output: 3.55 hp @ 15,500 rpm
Weight (w/o Muffler): 21.3 oz (603 g)
Displacement: 0.91 cu in (14.9 cc)
Bore: 1.09 in (27.7 mm)
Stroke: 0.98 in (24.8 mm)
Practical rpm: 2,000-16,500
Output: 3.55 hp @ 15,500 rpm
Weight (w/o Muffler): 21.3 oz (603 g)
Primary Accessories
| Stock Number | Mfr Number | Product Description | Quantity Needed |
| GPMQ4131 | GPMQ4131 | Great Planes Silicone Fuel Tubing Standard 3' | 1 |
| GPMQ4150 | GPMQ4150 | Great Planes Ultra Precision Fuel Filter | 1 |
| HCAP2550 | HCAP2550 | Hobbico 4-Way Wrench w/Plug Storage | 1 |
Field Equipment
| Stock Number | Mfr Number | Product Description | Quantity Needed |
| DTXP0300 | DTXP0300 | Duratrax Glow Starter C Battery | 1 |
| FUGP4202 | 4200BP2 | Fuji Batteries C Alkaline Battery (2) | 1 |
| HCAP3015 | HCAP3015 | Hobbico Hand-Crank Fuel Pump | 1 |
Optional Accessories
| Stock Number | Mfr Number | Product Description | Quantity Needed |
| HCAP3001 | HCAP3001 | Hobbico After Run Engine Oil 2 Fl Oz | 1 |
| HCAP3105 | HCAP3105 | Hobbico Top Fueler MkIII | 1 |
| HCAP3107 | HCAP3107 | Hobbico Top Fueler MkIII Panel Ready | 1 |
| OSMG5872 | 72403050 | O.S. Super Can Filter Large | 1 |
| OSMR2976 | 71521000 | O.S. Long Socket Wrench With Plug Grip | 1 |
