Dry sump venting open or closed.

[Ant]

Running a 3 stage Peterson dry sump pump, I am seeking information to see if its worth running a closed vacuum system with no engine venting or some valve cover venting, due to the pump only having 2 scavenge sections. I have valve covers that have a pop off pressure valve in one cover, the only venting is from the scavenge line through the oil tank which has two fittings for breathers to a puke can.

I was considering removing the pop off valve and fitting a vent so air can flow through engine for more road use than race, as one issue with a closed system is condensation build up causing rust?

[4pipes]

I run a system with an Aviaid Dry Sump system on a stroked alloy 427. Used to have several small leaks, one probably was the rear main side seals and one at the distributor. These engines can develop quite a lot of crankcase pressure.

I sealed the engine and used a calibrated vacuum leak on the manifold, so that at idle I get around 2-3 inches of vacuum. I still vent the dry sump tank.

I used a regulator from Peterson:
http://www.petersonfluidsys.com/engine_breath.html

No more leaks! Love it.

[vector1]

you can vent with no problems, if you run a closed crankcase you should put some type of regulator in, or provide for it, or the possibility of pulling too much vacuum which the consensus is anything above about 12" can be detrimental to the engine. the size of the pump sections also has an effect on how much vacuum you will pull. with my 3 scavenge sections i can pull around 5" running at 2000 rpm, so i do run a vacuum regulator. i have also owned a race car from a knowledgeable individual that used an open system, with a breather, so either way imo, whatever works.

[Ant]

Thanks for the info. I am running an alloy engine, Peterson pump has a large pressure section and std 2 stage scavenge, in hindsight maybe I should have gone with a 3 scavenge section pump if I wanted to increase HP. This engine isnt running over 7200rpm.

I assume the regulator allows air in (as it has a filter) to reduce vacuum.

[Gaz64]

The regulator is adjustable for the maximum vacuum that be generated in the crankcase.

Why it adjustable up to 29 inches (near perfect vacuum) is anybody's guess.

Here's another type:

http://www.gzmotorsports.com/VCV102B...rol-Valve.html

[vector1]

from what i understand with vacuum you could estimating increase hp 10-20, it also helps the oil drop out of the crankcase because the vacuum doesn't hold liquid as well.

the regulator does have a filter. you can also experiment with putting a hole in the blowoff valve piece below the spring. if that doesn't work then put a piece of aluminum between the spring and valve to block it and put a regulator in. if you are pulling 2-3" at idle which is what mine does, you will need something. the 2 scavenge stages are probably enough, they just have to be in the right places. sounds like you have a good handle on it.

[vector1]

btw i have read you don't want to run any vacuum til the engine is broken in as the rings won't seal properly.

[Ant]

Originally Posted by vector1

btw i have read you don't want to run any vacuum til the engine is broken in as the rings won't seal properly.

Thats a good tip thanks.
I have read that running a non vented engine on the street can promote condensation/rust in the engine, this car will see some road miles for testing etc.
As you mention there maybe some benefit to run the regulator, I thought closed at the track and vent for the street. I will try and rig up a system where I can alternate the plumbing between the regulator or the puke tank.

[Morris]

Ant
We use 3 scavenge sections......2 each in the oil pan.....and 1 in the back of the intake manifold.......with a tube mounted in the valley....

Vent with blue thunder valve covers and -12 vent hoses to a catch can......also -12 line off of dry sump tank.....to another catch can....

That was the only way we could stop oil puking out of the motor.....BTW....we run the motor hard 2800-7000


PS....unless a engine and it seals are built to run a vacuum ....might not be a good idea....seals need to be reversed....

[Ant]

Originally Posted by Morris

Ant
We use 3 scavenge sections......2 each in the oil pan.....and 1 in the back of the intake manifold.......with a tube mounted in the valley....

Vent with blue thunder valve covers and -12 vent hoses to a catch can......also -12 line off of dry sump tank.....to another catch can....

That was the only way we could stop oil puking out of the motor.....BTW....we run the motor hard 2800-7000


PS....unless a engine and it seals are built to run a vacuum ....might not be a good idea....seals need to be reversed....

Morris, I tend to agree with you, as some racer friends have had similar problems with oil puking, and reversing the seals makes sense as well, dont want to go down that path really. I gather you solved the puking when vented the covers?

[Morris]

Originally Posted by Ant

Morris, I tend to agree with you, as some racer friends have had similar problems with oil puking, and reversing the seals makes sense as well, dont want to go down that path really. I gather you solved the puking when vented the covers?

Ant.....yes we did solve the puking issue.....and I believe the Blue Thunder valve covers helped a bunch......I'll get you some photo's tomorrow...

[Morris]

Ant

Here's a couple of Photo's of the valve covers and catch can and tank and catch can vent..... Hope it helps out...

[Ant]

Originally Posted by Morris

Ant

Here's a couple of Photo's of the valve covers and catch can and tank and catch can vent..... Hope it helps out...

Thank you for the photos, that is a good adequate system I gather the FE can breath a bit more compared to SBF when you have the hp and rpms like you have.

[vector1]

reversing the seals is one way, the other is to use double lipped seals.

[vector1]

I've settled on running my Dailey pump at 90+% which is the next step up from 75%, the 75% was a tad low at the idle for some reason (engine builder I would guess), and I was under the impression for the air/oil separator to work it needed so much rpm, which the 90+% ratio would provide at the lower running rpm's, so let'er spin. It's a neat pump, you can also change the size of the internal pressure gear, and the tolerances are very close on the inside and what he uses for bearings is interesting. Nice stuff and a great guy to work with.

[PLDRIVE]

Ant anything under 12" of vacuum is not going to cause any problems, but
go with what your builder says.

Vector1 I guess Dailey ops for a smaller pressure section. He is does make nice stuff.
Mine runs at 65% and idles at 35psi hot, with 1.25 pressure section.

[Ant]

Originally Posted by PLDRIVE

Ant anything under 12" of vacuum is not going to cause any problems, but
go with what your builder says.

Vector1 I guess Dailey ops for a smaller pressure section. He is does make nice stuff.
Mine runs at 65% and idles at 35psi hot, with 1.25 pressure section.

This pump has a 1.45 pressure section, if its too much I can fit the 1.25 gears with spacer...

[Z-linkCobra]

Interesting read guys.

[Z-linkCobra]

Let me throw something out there for thought. Im running an all aluminum 302 with a weaver brothers 5 stage pump. Closed valve covers, tank is vented to puke tank with an air cleaner. I was thinking of running a line from the bottom of my puke tank back over to the motor and allow the vacuum to pull any oil out of the puke tank back into the motor.

I realize that what comes out of the puke tank sometimes doesn't look to good. It did however come out of the motor and nothing but a little moisture in the oil. I run a belt drive distributer and crank trigger. I was thinking of tapping into the distributor hole plug and running in right there.

Thoughts?

[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.