fast back oil tank vent

I have the central oil tank, not the one that fits on the right side. This one has a vent..a tube...on top of the tank and the other one is a small hole at the bottom of the tank facing the cylinders. How does this set up work? There is nothing to connect to at the bottom of the tank. It's just a hole, no tube.

seattle##gs said:

I have the central oil tank, not the one that fits on the right side.

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The central oil tank was fitted to the 'S' Type and '1970' Roadster models, Edit: There's no evidence of the central oil tank having been fitted to the Fastback which would also require the 'S' battery tray, RH battery access panel and 'fixed' LH panel with ignition key mount.

seattle##gs said:

This one has a vent..a tube...on top of the tank and the other one is a small hole at the bottom of the tank facing the cylinders. How does this set up work?

Click to expand...

The "vent" tube on the top is normally the connection for the (timed) crankcase breather, however, see the link, below.

The small hole in the front plate is the oil tank breather as it is also the rear 'wall' of the airbox. The hole has a pipe that runs up to the inside of the breather tower.

Fastback to '1970'. Later Fastbacks had the same triangular-shaped side tank as other models.

There are two (maybe three?) versions of the central oil tank. The early type where the crankcase breather spigot is attached to the breather "top hat" tower. The later oil tank has the breather spigot attached to the top of the tank presumably to reduce the amount of oil blown into the airbox.