V-twin engine 75° crank pin offset for the rest of the world. Generally, a two-cylinder engine with the cylinders arranged at any angle greater than zero degrees and less than 180 degrees may be classified as a V-twin, although an angle that approaches zero is not practical. Despite Ducati referring to its 90 degree twin cylinder engine as an "L-twin"—with the front cylinder nearly horizontal and the rear cylinder almost vertical, there is no technical distinction between V-twin and L-twin engines. Assuming correct counterweighting, a 90 degree V-twin will achieve perfect primary balance. However, the 90 degree layout will produce an uneven
Type 97 90 mm Infantry Mortar Type 97 90 mm Infantry Mortar The Type 97 90 mm Infantry Mortar was a simplified version of the Japanese Type 94 90 mm Infantry Mortar. The Type 97 designation was given to this gun as it was accepted in the year 2597 of the Japanese calendar (1937). The Type 90-mm mortar is a Stokes-Brandt type mortar similar in appearance to the US 81-mm mortar, M1 and the Japanese Type 97 81 mm piece. It is believed that the 90 mm weapon has been introduced later than its model number would imply, as a captured specimen was marked "Model 97