Project 03 · January to May 2026
Mitsubishi 6G72 V6 CAD Assembly
A V6 SOHC engine I reverse engineered in SolidWorks from part drawings and reference dimensions.
Cutaway view of the pistons, crank, timing belt and both cam banks
- Unique part types
- 40+
- Cylinders, V-configuration
- 6
- Bore
- 91.1mm
- Stroke
- 76mm
- Why
- I wanted practice at working off real part drawings and reference dimensions instead of designing from a blank sketch, and at managing an assembly big enough that one mistake in one subsystem, a bore diameter or a journal offset, breaks the way a dozen other parts mate.
- Result
- I checked the mechanical motion with a SolidWorks Motion Study, so the crankshaft actually drives the pistons and the valve train through the constraints I built rather than sitting in a static exploded view.
- Open
- I did not get to tolerancing given how long the project ran.
- Next
- The obvious next step is the part I left out on purpose, which is the combustion system.
How the power flows
Every rotating part is constrained to the one before it, so you can step through the chain below and see what drives what.
Step 1 of 4
Combustion drives the pistons
Each piston travels up and down in its bore with its connecting rod constrained concentric to the crankshaft journal. Six pistons across two banks put rotational force into the crank.
Model views
Isometric
Front elevation
Rear isometric
The assembly
The photo of the real 6G72 is there for comparison and is not my own work.
Motion study
This is an actual kinematic simulation running off the constraints, not a rendered animation.
SolidWorks Motion Study, slowed to 0.75× so it is easier to follow
Key dimensions
| Cylinder bore | 91.1 mm |
| Cylinder stroke | 76 mm |
| Valve spring | 30–34 mm |
| Rod journal | 50 mm |
| Main journal | 60 mm |
| Configuration | V6, SOHC |