Re: The Duchess Project: 1940 Super 8 Convertible Sedan

Posted by HH56 On 2018/1/7 13:15:58

The horizontal tube was continued after the war but I believe some have said it may have been discontinued by the 23rd series 356. I would need to find it in the parts book to confirm where it stopped.

According to one of the bulletins the reason for it was the oil filter. It was found the round shape of the filter canister and location of the fill tube created turbulence and some blocking of the air flow on the 356. The longer fill tube and different cap was made available for all engines but the 356 with the stock filter and confined internal passages was predominately the engine of concern. In addition to blocking some flow the turbulence actually created a low pressure area behind the filter which could cause a sort of vacuum. The horizontal tube was an effort to feed air from the fan directly into the cap and force air thru the internal confined passages.