A Over Head Valve (OHV) engine is an internal combustion engine with its valves placed in the cylinder head.  
This model is designed to be (de)mountable with allen bolts. 
As such the finished model is very suitable for educational purposes.
Dimensions:   177 x 229 x 206 mm.
Weight:  0.6 kg.


SOME FEATURES OF THE MODEL
- See through crankcase and cylinders|
- Open and closed Cylinder Heads
- Moving crankshaft and pistons
- Valve control by camshaft, push rods and valve rockers
- Valve clearance adjustment
- Valve timing adjustment by idle gear
- Engine head with inlet and outlet canals
- Screwable exhausts and carburetors
- Carburetors with moving gas slide
- Removable Spark Plugs

The model is prepared to add a gearbox: [https://makerworld.com/en/models/778128](https://makerworld.com/en/models/778128)
 

METAL HARDWARE
- 3 and 4 mm Allen Wrenches.
- 4 coil springs for the valves, 16 mm width x 20 mm height. Wire thickness 0.8 mm (AliExpress).
- 11 M5 x 16 mm Allen Bolts.
- 8 M4 x 12 mm Allen Bolts.

 

PRINTING AND ASSEMBLY

The parts should preferably be printed on a smooth build plate.
Avoid elephant foot and over-extrusion.

I printed the model with PLA+ filament, layer height 0.16 mm. 
Use glue where indicated.

Printing and assembly is in alphabetical order. 
For exploded 3D views have a look at the “Do not print” map (Download STL-files).