Dry sump venting open or closed.

[Ant]

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

Mark what you are saying is the pop off doesn't react quick enough for pressure spikes?
I am intending on running a Peterson inline Pop off from my fuel pump plate, I assume Peterson have gone a little heavy in the return spring so the valve seals in most situations so its a matter of me finding a light spring to hold the valve in place.
My Nascar Ford valve covers have a pop off valve welded on approx 3/8" ID I was going to weld a -12 boss fitting there and use a breather for road, and cap it for race use.

[PLDRIVE]

If the engine goes from pulling a vacuum to positive pressure it could blow out a seal in the engine. The Peterson pop off spring pressure is more for catastrophic failure then repeated positive pressure cycles. My knowledge is not from personal experience, its from my engine builder (He builds dry sump engines on a weekly basis).

I would consider cost of a spring cheap insurance.

MP

[Ant]

Originally Posted by PLDRIVE

If the engine goes from pulling a vacuum to positive pressure it could blow out a seal in the engine. The Peterson pop off spring pressure is more for catastrophic failure then repeated positive pressure cycles. My knowledge is not from personal experience, its from my engine builder (He builds dry sump engines on a weekly basis).

I would consider cost of a spring cheap insurance.

MP

I gotcha and that makes sense. The valve cover pop off has a very light spring hardly enough to seat it so I guess that won't take much pressure to work..I might consider leaving that there, and if I want minimal vacuum I can adjust regulator down to 2"

[Z-linkCobra]

Well pldrive you ask a good question. My valve covers are sealed and my tank is sealed other than a line running from the top of the tank to an overflow/catch can. Im not running any type of vacuum regulator or any of that. I am learning a little on this thread. Going to have to do some more reading.

[PLDRIVE]

Ok now we are getting somewhere. Z Link from what u described u are running a sealed system. Have u checked to see what the vacuum is?? If not u need to .

[Z-linkCobra]

Have not checked vacuum. Have been wanting to just have not got around to it. Car has not gotten on the road for any length of miles. Just up and down the street and to the gas station. Fighting trying to get this thing titled.

I have done some reading and what not on several sights including Petersons. I plumbed my system based off of what the majority said. You guys are talking about pressure release valves and vacuum release valves. My car is strictly street...no desire to race it.

I was just curious about using the vacuum generated by the pump to pull any oil out of the catch can back into the motor so I dont have to worry about the catch can over flowing should i forget to check it.

One way I saw to plumb a system was to vent the tank back to the valve cover and run a pressure release valve on the opposite end of the same valve cover. No tank vent at all.

[vector1]

I've read a guy refer to the Weaver pumps at not real efficient, or in other words not pulling a lot of vacuum or trying to pull vacuum and not being able to.

[GBowman]

I wouldn't want what I see in my breather can (mounted right off of the reservoir) to re-enter my engine, Iv'e never seen any oil only water. I am working through some growing pains on a dry sump system so I don't have much experience, however this has been my limited observation thus far. My breather has a valve and stem to drain it and only water so far.