1960 Corvair vented oil cap adapter

This is an adapter I designed to allow the use of a vented oil filler cap on my 1960 Corvair when it was pushing oil out of the dipstick tube due to excess crankcase pressure. The adapter just snaps on to the oil fill neck, and the cap is a friction fit.

I was able to eliminate my problem by clearing out my road draft tube, but it may still be useful to other Corvair owners as it's a common issue. It should work on most Corvair engines, but I can't guarantee it.

The oil cap used is a Gates 31069 (originally for AMC V8 engines, currently less than $6 on Amazon). You'll have to figure out your own venting scheme. I was going to route some 1/2" ID heater hose from the cap out through the corner of the engine-to-body seal.

This is exposed to engine temps and hot oil, so choose material accordingly. I used PETG.