GT3+ 4.0 Crankshaft, 80.4 mm Stroke
Billet EN40B crankshaft taking the M64 to 4.0 litres, developed from the OEM GT3 4.0 crank with more rigidity for higher rpm.
Engine Internals In production confidence: high
Manufacturing
| Manufacturer | Swindon Powertrain |
|---|---|
| Origin | 🇬🇧 United Kingdom Manufactured here Swindon Powertrain, UK. |
| Process | CNC Machined |
| Additively manufactured | No |
| Material | EN40B nitriding steel |
| Notes | Billet machined in EN40B, a nitriding steel — the crankshaft is exactly the part that should not be made in a light alloy, and this one is not. Described as an evolution of the OEM GT3 4.0 crankshaft with improved rigidity for greater rpm capability. Swindon ask to be consulted on rod requirements if it is not run with their own connecting rods. |
Published figures
| Basis | Published by the manufacturer; not independently verified. |
|---|---|
| Notes | 80.4 mm stroke. With the 102.7 mm bore of the matching piston set this gives 3,996 cc across six cylinders. |
Fitment
| 964 | All models |
|---|---|
| 993 | All models |
Sources
- GT3+ 4.0 Crankshaft - 80.4mm Stroke — Swindon Powertrain, accessed 2026-08-18