Vac Pumps and blown engines

Just wondering if anyone has tried vac-pumps or dry sump pumps which create a crankcase vacum back to back with and without on a blown engine.
I know people are using either but was wondering if there was a gain in performance or boost by changing nothing but the addition of a vac pump??

Or for that matter does it create a problem elswhere, ive been told the pin and the little end of the rod can run drier???

We log our crank case pressure and we make around 4 psi+ and its stable througout the run varying 1psi tops with 54lbs boost I was hoping (wishing) If the rings sealed better and the crankcase pressure was 0 (approx) would that mean the eng would make 4 psi more boost????

Anyone tried it back to back or had a play??

 

Moroso designed a vacuum pump for large inch nitrous and blown engines three years ago. We put it on Steve Salvadore's IHRA Pro-Mod and ran it for two seasons.
It ran well. The down fall is it has alot of plumbing that is required to make it work CORRECTLY. We acheived 16 in/hg at staging, and would drop to 6 to 8 in/hg at the 1st gear shift, and hold that the whole way down the track.
The tough part is building the engine to make this much vacuum. You CANNOT take an existing engine and expect it to do this. There are things that have to be done ahead of time. A Billet Block is a must. Cast blocks don't hold the sleeve in as well, and creates to much blow by.
NHRA banned the use of these on blown cars before I could even get it on a car. They didn't like the check valves required in the burn down tubes.
I know how much power it is worth, most people who don't deal with these systems typically don't beleive the number. Those who do deal with vacuum systems agree with the power gain.
A vacuum pump will tell you VERY QUICKLY if something is wrong with your engine. It is a great tuning device as far as detonation, and how rich and consistant your fuel system is. I worked with these systems for 9 years now. I wish we could use them.
Some teams have built in scavenge pumps that will create vacuum in the engine. I know of four teams that are doing this, and they should work. I don't have specifics, but I can say that it can do the job, if everything is correct.

scotth@moroso.com

 

I know from running my NOS motor a vacum pump and a pan vac sensor on the race pak made us aware of many problems before they became an issue. With that data you can know from run to run how healthy the motor is and Like Scott said you can definately see where your fuel system problems are!

 

Hate to thread dig but I was going to ask this very same question. did a search, not much input. ANyone have any NEW experiance trying to pull a vacuum on a blown motor or is it futile? Just asking.