THIS WW2 BSA WM20 ENGINE HAS BEEN CAREFULLY SECTIONED SO THAT VALVE GEAR IS SHOWING AND WORKS .
TURN THE HANDLE AND CRANK TURNS WITH PISTON GOING UP AND DOWN AS IT WOULD .
THE HEAD AND CYLINDER BARREL BOTH CUT TO DHOW INTERNALS .
THE TIMING GEARS ALL MOVE AND THE OIL PUMP HOUSING IS CUT TO VIEW THE PUMP .
A MAGNETO COULD BE FITTED AS WE DID IN THE MARK 2 VERSION .