Barry wrote
>Well, ya left it open with that remark :-)- Draught tubes (or draft tubes)
>as normally installed on vehicles way before emission controls were
>implemented, typically went straight down and ended *just* below the frame
>directly in the air stream. These had an angled cut facing rearward to
>create a "low pressure" area just behind the tube opening to draw the
>vapors out. The idea is to prevent pressure buildup by creating a partial
>vacuum to extract the vapors and create a slightly less than atmospheric
>condition in the engine itself which, by the way, also helps the oil seals
>do there job. The cap on that particular alloy cover (if it's anything
>like the one on my GT6) is designed to work with a negative pressure closed
>crankcase type system.
>With the pipe connected as described, the engine needs to 'pump' the vapors
>out creating a positive pressure inside the engine leading to the condition
>you have now- Anyway, that's my conclusion on the condition you've described.
>
>
>Barry Schwartz (San Diego) bschwart@pacbell.net
>
>
Makes sense,will try and see what happens
Thanks
Cameron
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