Dry sump venting open or closed.

[PLDRIVE]

Ant
I would try what Dailey says first. Heres some food for thought. An engine only needs a so many GPM of flow (every engine is different), So if u have excessive pressure at idle and or upper Rpm then the pump is bypassing (wasted HP) If u can get it to idle at 15 to 20 psi at idle HOT and make 60 or so PSI at WOT (very little bypass) then u are sized correctly on the pressure section. In an ideal world a 1.0 pressure section and say 1.75 to 2.0 scavenge sections would be a good combination if your goal is to achieve a lot of vacuum.
Ant I will be highly surprised if your pump will pull any where near 19". Thats no poke at Dailey he makes one of the best pumps available. I believe i achieved a max of 8" with regulator set at 10" before the engine got hot(i have a 5 stage with 1.5 and 1.75 scavenge sections). I would be much more concerned with positive pressure when the RPMs or low on your sealed system (from full throttle to heavy braking to back on gas). Engine needs to pull vacuum at idle on a hot engine otherwise u could over pressure the engine. The peterson pop off is design for engine failure not a continuous pressure burps. I would change the spring (softer) so that it just barely seals. Remember you are dealing with surface area in the engine and it has A LOT of surface area compared to the peterson 1" pop off. It could blow a seal without the pop off every opening.

My recommendation is to try what u have, and see what the results are (pump). Replace spring as soon as u get the pop off.
Make sure it will pull a vacuum at idle while engine is warm, prior to doing you dyno pulls (if u run it sealed).

Hope this helps

Mark


Zlink
Why are u not running sealed with the 5 stage pump?? Scavenge sections too small to pull a vacuum??
I need to think about what u proposed for a while. Maybe one of the pros will comment.