Willys Overland Knight Registry

International Truck - "Green Diamond" Engine

The 1933 International Truck Model D1 used the 80 bhp engine intended for the side valve Willys 99, which in itself was developed by Willys from the 1930 - 1933 65 bhp Willys 6.  Refer Page 12 of the Willys 99 Sales Brochure.  When Willys sold the engine design to International, the same basic design was used on subsequent light truck models through to the late 1940's with very little change and was known as the "Green Diamond" engine.  The "Green Diamond" cylinder head and connecting rods will fit 1930 - 1933 Willys 6, however the bore and stroke are different, so the pistons and crankshaft by themselves are not interchangeable. With some work to allow for the differences in front engine mounts, cooling system hose diameters, etc, the complete engine could, and has been used in a Willys 6 restoration project.

International Truck - Green Diamond Engine
RHS View - International Green Diamond Engine

LHS View
LHS View - International Green Diamond Engine

Top View
Cyl Head stud spacing is identical to Willys 6

Rear (Flywheel end) View
Rear (Flywheel end) View

Front View 1933 Willys 6-90A Engine
Front Views - International on left, Willys 6 on right has smaller water pump cavity

Green Diamond Logo - Front LHS Water Pump Cavity View
Logo and water pump cavity views - International Green Diamond Engine

Cylinder Head Top View
International Cyl Heads can be used on 1930 - 1933 Willys 6 and are less crack prone

Cylinder Head Combustion Chamber View
International Cyl Head Combustion Chamber

Water Pump and Gasket Water Pump Side View
International water pump cannot be used on 1930 - 1933 Willys 6 because although the bolt pattern is the same, the impellor shaft centre line was changed to accomodate the slightly larger diameter impellor.

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