Project 02 — January–May 2026
Mitsubishi 6G72 V6 — CAD Assembly
A fully mated, motion-validated V6 SOHC engine reverse-engineered in SolidWorks from part drawings and reference dimensions — crankshaft, camshaft, valve train, and a 20+ part accessory drive, modeled and assembled from scratch.
Cutaway — pistons, crank, timing belt, both cam banks
- Unique part types
- 40+
- Cylinders, V-configuration
- 6
- Bore
- 91.1mm
- Stroke
- 76mm
Why this project
I wanted deliberate practice at two things a robot-arm-scale project doesn't exercise: reading real part drawings and reference dimensions instead of designing from a blank sketch, and managing a large assembly where a single mistake in one subsystem (a bore diameter, a journal offset) breaks how a dozen other parts mate.
The 6G72 was the target: a real Mitsubishi V6 SOHC engine, reverse-engineered feature by feature — cylinder block, crankshaft and connecting rods, camshafts and the full valve train (rocker arms, followers, springs), timing belt and cam gears, intake and exhaust manifolds. Every dimension was pulled from reference measurements and constrained with real geometric mates, not eyeballed.
Mechanical motion was validated with a SolidWorks Motion Study — the crankshaft actually drives the pistons and valve train through the modeled constraints, not just a static exploded view. Tolerancing wasn't applied given the project timeline; the emphasis here is assembly complexity and correct kinematic relationships between parts.
How the power flows
The assembly isn't a static shell — every rotating part is constrained to the one before it. Step through the chain to 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
The completed assembly from three angles — intake and exhaust manifolds, timing belt, and both cylinder banks in place.
Isometric
Front elevation
Rear isometric
The assembly
SolidWorks screenshots of the actual model, plus a dimensioned 2D drawing and the full exploded-view BOM. The reference photo of the real 6G72 is included for comparison, not as my own work.
Motion study
Crankshaft rotation drives the pistons and, through the timing belt and cam gears, the full valve train — validated as an actual kinematic simulation, not a rendered animation.
SolidWorks Motion Study — slowed to 0.75× for clarity
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 |
Bill of materials
A partial view of the part list — enough to show the scale of what has to mate correctly for the assembly to move as one system.
| Part | Qty |
|---|---|
| Engine block | 1 |
| Crankshaft | 1 |
| Crank bushing | 2 |
| Camshaft | 1 |
| Camshaft (opposite side) | 1 |
| Valve | 12 |
| Valve washer | 12 |
| Rocker arm | 12 |
| Rocker follower | 12 |
| Cylinder head | 2 |
| Cylinder head cover | 2 |
| Piston (part 1–4 sets) | 24 |
| Lower block | 1 |
| Oil pan | 1 |
| Intake manifold | 1 |
| Exhaust manifold + mirrored | 2 |
| Exhaust manifold gasket | 2 |
| Head gasket | 2 |
| Cam gear | 2 |
| Flywheel | 1 |
| Timing belt | 1 |
| Pulley | 2 |
| Air filter | 1 |
What I'd build next
What this model proves is synchronized mechanical motion — multiple axes of rotation driven from a single input, with pulleys and gears enforcing the timing relationships between them.
The obvious next step is the part I deliberately left out: the combustion system. Modeling the fuel path, injectors, and spark timing would turn this from a kinematic assembly into something that could actually be simulated as a running engine — which is a meaningfully harder problem than geometry, and the one I'd want to take on next.