Shawn wrote:
> 3) The vent tube or "road draft tube" is designed to pull the blow-by
> gasses out of the crankcase and is an early attempt at Positive Crankcase
> Ventilation (PCV). A slight negative pressure is necessary on the
> crankcase of any A-series motor to prevent oil from seeping out the
> rear main seal. Alternatives to the draft tube are either a gulp valve
> fitted to the intake manifold like the '67 models used or dragracers
> often plumb a rearward angled tube into the header collector to draw
> the fumes out of the crankcase (unknown if the latter has been done on
> our engines).
Yes, David Vizard talks about it at length in his book.
> Moral: You need PCV in your engine.
Yes! Been there, done that, reconnected it...
Ulix __/__,__
.......................................................... (_o____o_)....
'67 Sprite
|