Gas and oil tanks for 45 twins from 1937 on

1937 was a turning point for Harley-Davidson's small twins: the SV engine was converted from total loss to circulating dry sump lubrication. As a result, not only was the shape of the tank redesigned (as was also the case with the large SV twins), but the tasks were also redistributed between the tank halves for the series tanks. From now on, only the fuel for the carburator was bunkered in the left tank, while the lubricant was located in the right tank. After dismantling, you can also see that “tank halves” may not be the right term: the volumes are as different as they can possibly be. 3.4 gls gasoline to 3.5 qts oil is the ratio, i.e. 13 l to 3.3 l to our metric friends. The left gas tank reaches like large bubble through the frame tubes to the right side and the right oil tank is more of a double-walled shell. The conversion of the lubrication system also results in an increase in the number of oil tank connections: the new tank has threads for three lines and a drain plug.

Equally sized tanks on both sides for the racers

Because more oil dissipates heat better and oil coolers complicate the oil circuit, the WR racers get two mirror-image tanks, each with a capacity of 5 liters. You don't need that much gas anyway when you're racing in the oval.