12XZ Speed Spec III
The O.S. engineers have taken superior Speed Spec performance to the next level! In addition to smoother acceleration from idle to full throttle, the 12XZ Speed Spec III also has increased low-to mid-range torque. Don’t worry: the impressive top end speed remains the same!
- The head button’s design has been optimized for better performance and improved acceleration
- The cylinder liner and piston have been redesigned to improve mid speed torque and fuel mileage
- The shape of the mixture control slide valve allows for a smoother flow of fuel and air
- Available separately is the T 1070SC L52 silencer, which has been tuned to match the 12XZ Speed Spec III engine
The crankshaft features DLC coating, a pressed-in Tungsten weight and ceramic rear ball bearing.
The cylinder liner’s outer diameter is slightly thicker (0.5mm), resulting in redesigned port angles for better air/fuel flow. The piston features a tapered surface with a depression in the middle to work better with the head button.
The outer head is 1mm shorter and sits 6mm lower over the crankcase, for less overall weight while also lowering the CG.
The new 12F2(B) carburetor delivers sharp acceleration and instant throttle response.
- Specifications
- Parts Listing
- Accessories
- Gallery
- News
Displacement: 0.128 cu in (2.1 cc)
Bore: 0.543 in (13.8 mm)
Stroke: 0.55 in (14.0 mm)
Practical RPM range: 5,000-44,000
Output: 1.73 hp @ 35,000 rpm
Weight: 7.9 oz (225 g)
Includes: 12F2(B) carburetor, RP6 glow plug, exhaust seal ring, dust cap set, 5.5 mm red carb reducer
Primary Accessories
| Stock Number | Mfr Number | Product Description | Quantity Needed |
| ODOP3320 | ODOP3320 | O'Donnell 20% Racing Quart | 1 |
Field Equipment
| Stock Number | Mfr Number | Product Description | Quantity Needed |
| DTXP0300 | DTXP0300 | Duratrax Glow Starter C Battery | 1 |
| HCAP2550 | HCAP2550 | Hobbico 4-Way Wrench w/Plug Storage | 1 |
| HCAP3001 | HCAP3001 | Hobbico After Run Engine Oil 2 Fl Oz | 1 |
Optional Accessories
| Stock Number | Mfr Number | Product Description | Quantity Needed |
| DTXR0185 | DTXR0185 | Duratrax Engine Tuning Screwdriver | 1 |
| DTXR0187 | DTXR0187 | Duratrax Engine Tuning Tool | 1 |
| OSMG2973 | 72107600 | O.S. T-1070SC L52 Pipe Set | 1 |
| SULQ2387 | S187 | Sullivan CT-1 Screen Fuel Filter | 1 |
The O.S. 12XZ Speed Spec III wins the 2012 Japan Nats in its debut!
The 1/10 Scale GP Touring Car Japan Nats was held September 7-9 at the Mie Prefecture circuit in Hokusei. Even with intermittent rain on the final day, Takaaki Shimo took home the championship for the second time in 5 years. One of the major factors in his victory was equipping his car with the O.S. 12XZ Speed Spec III engine — it produced the power and speed needed to stay ahead of the competition, along with improved fuel mileage that allowed Shimo to plan his pit stops more efficiently. These are just some of the advantages you’ll enjoy in your own racing when you mount a 12XZ Speed Spec III engine in your car!
