See other engines in this family
Mazda 13B-MSP specs: 1.3L (80 ci) 2-cylinder, 10:1 compression. Rated 197-238 hp, 2004–2011. Used in the Mazda RX-8. Rotary. Rod ratio and piston speed.
The Mazda 13B-MSP is exactly square — 3.1496" bore and 3.1496" stroke are the same — which splits the difference between a high-revving layout and a torque layout. The 3.1496" stroke does not reach 4,000 ft/min of mean piston speed until about 7,600 RPM, so piston speed is not what limits this engine's revs — valvetrain and breathing are. Each of the 2 cylinders displaces 40.0 ci (655 cc).
10:1 on aluminum heads is in the range that usually runs on pump premium; aluminum sheds heat faster than iron, which makes the same number a little more forgiving.
It is one of 6 engines in the 13B family, all of them 80 ci — the differences between them are in compression, heads and rating, not displacement. 16 factory variants share these dimensions, rated from 197 to 238 hp across 2004–2011.
| Displacement | 80 ci / 1.3 L |
|---|---|
| Cylinders | 2 |
| Compression ratio | 10:1 |
| Bore/stroke ratio | 1 |
| Block material | aluminum |
|---|---|
| Head material | aluminum |
| Valvetrain | Rotary |
| Fuel type | gas |
| Advertised HP | 197–238 hp |
| Years | 2004–2011 |
| Year | Version | HP @ rpm | Torque @ rpm | Comp. |
|---|---|---|---|---|
| 2004 | 13B-MSP net | 197 @ 7200 | 164 lb-ft @ 5000 | 10:1 |
| 2004 | 13B-MSP net | 238 @ 8500 | 159 lb-ft @ 5500 | 10:1 |
| 2005 | 13B-MSP net | 197 @ 7200 | 164 lb-ft @ 5000 | 10:1 |
| 2005 | 13B-MSP net | 238 @ 8500 | 159 lb-ft @ 5500 | 10:1 |
| 2007 | 13B-MSP net | 212 @ 7500 | 159 lb-ft @ 5500 | 10:1 |
| 2007 | 13B-MSP net | 232 @ 8500 | 159 lb-ft @ 5500 | 10:1 |
| 2008 | 13B-MSP net | 212 @ 7500 | 159 lb-ft @ 5500 | 10:1 |
| 2008 | 13B-MSP net | 232 @ 8500 | 159 lb-ft @ 5500 | 10:1 |
| 2009 | 13B-MSP net | 212 @ 7500 | 159 lb-ft @ 5500 | 10:1 |
| 2009 | 13B-MSP net | 232 @ 8500 | 159 lb-ft @ 5500 | 10:1 |
| 2010 | 13B-MSP net | 212 @ 7500 | 159 lb-ft @ 5500 | 10:1 |
| 2010 | 13B-MSP net | 232 @ 8500 | 159 lb-ft @ 5500 | 10:1 |
| 2011 | 13B-MSP net | 212 @ 7500 | 159 lb-ft @ 5500 | 10:1 |
| 2011 | 13B-MSP net | 232 @ 8500 | 159 lb-ft @ 5500 | 10:1 |
Factory specification sheet.
These records share identical bore, stroke, displacement and compression. They differ by model year and factory power rating.
| Year | Advertised HP | Code |
|---|---|---|
| 2004 | 197 hp | 13B-MSP |
| 2004 | 238 hp | 13B-MSP |
| 2005 | 197 hp | 13B-MSP |
| 2005 | 238 hp | 13B-MSP |
| 2006 | 212 hp | 13B-MSP |
| 2006 | 232 hp | 13B-MSP |
| 2007 | 212 hp | 13B-MSP |
| 2007 | 232 hp | 13B-MSP |
| 2008 | 212 hp | 13B-MSP |
| 2008 | 232 hp | 13B-MSP |
| 2009 | 212 hp | 13B-MSP |
| 2009 | 232 hp | 13B-MSP |
| 2010 | 212 hp | 13B-MSP |
| 2010 | 232 hp | 13B-MSP |
| 2011 | 212 hp | 13B-MSP |
| 2011 | 232 hp | 13B-MSP |
1 factory vehicle, 2004–2011. Each year opens that model's engine table.