In a message dated 98-02-13 13:30:09 EST, bschwart@pacbell.net writes:
> Very early engines, before the advent of positive
> crankcase ventilation (PVC), used what was commonly called a draught tube,
> which was simply a tube from the crankcase (usually on the push rod covers
> on the side of the block, when engines had these) to a point under the car,
> directly in the air-stream, with the bottom cut or exit angled so that the
> air rushing under the vehicle caused a low pressure area at the tube exit,
> and would draw the vapors out.
>
The later TR4's had a vent tube in the top of the valve cover. This was
connected by a rubber tube to a metal "y" fitting. The two sides of the "y"
were connected by rubber tubes to the center of the metal air cleaners. That
way the vapors went back into the engine rather than out into the air. The
"y" fitting itself is held in place by the bolts which hold the carburetors in
place.
Someone (I deleted the message) asked about the air cleaners for these later
TR4's - repros of the air cleaners are readily available from the "big
three". Cheers.
Art Kelly
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