Not even close....4 is a lot closer...4 large stages that
is...they come in different widths depending on what pump
you use. Might want to call whoever made it for sizing
advice but I bet they opt for 4 large scavenge stages..
Might want to put some filler in the block too if this
'expansion' is not caused by an 'explosion'.. burned piston
or disappearing rings. i would put 3 in the pan and 1 in the
valley then vent the tank with a -20 to the tank.. If you
really think about the pressure you are playing with a -12
is a bit on the small side. I would run -16 scavenge if need
be too..
Dave Dahlgren
Jim Dincau wrote:
>
> Hi all, another poll,
> On the modified (blown/fuel), because of past experience with torching
> pistons, we run two number 12 lines direct to atmosphere from the valve
> covers. I know this isn't the most environmentally friendly thing to do but
> we have ballooned oil pans and catch tanks before and they are expensive to
> replace.
> On unblown gas dry sump engine, will a two scavenge stage pump pull
> enough vacuum to allow venting the tank only? If additional vents are
> required is the rocker can or the tappet chamber a better place to vent?
> Jim in Palmdale where it has actually rained an inch this month
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