High performance engines and pcv systems

What needed to keep the oil in the engine at higher rpm's. In my 511 i have a pcv valve in the pass side cover and a -10 hose on the driver side cover connected to the air cleaner. Not enough as it blows out more oil now than it did with just 2 breathers. Should there be breathers in the covers as well as pcv valve?

The "classic" setup on a (moderately) high po engine is PCV valve on pass side and an open VC breather on drivers side. Valve covers well baffled on both sides.

This has worked well for me on a warm 496 that sees road track time.

I guess the 10AN line to your air cleaner is a problem. I guess a fouled air cleaner element?

A high cylinder pressure high po engine will have more blow by when hammered vs a stock engine (even if the hi po engine is healthy and tight). It needs to have a free vent to atmosphere for those times. The vent will act as an air intake for the crankcase when cruising... it lets air in and the PCV sucks fumes out.

Ok. So makes no difference which side pcv valve is on? Any harm with the -10 hose to air cleaner and a breather in same cover?

Yep, I do the PCV valve on passenger cover and a K&N open breather modded to fit the stand on the drivers side cover.

I've used cheap, chrome Mr. Gasket breathers in the past and they simply can't flow enough air at higher rpm. Years ago my dipstick would blow out of the tube because of crankcase pressure buildup with one after 4.56 gear install..

I use a #12 Peterson breather. They are really well built and screw right into the valve cover. If the Peterson breather doesn't work then you can hook up a remote breather tank. I've done the remote tank before and it works really well for big race engines. Mount the remote tank up by the radiator and run a #12 line from the valve cover.

2 of those breathers on 1 cover would look cool and provide plenty of venting as well.

The clean air intake and PCV to the manifold should be separated by the entire engine if possible to pass all the crankcase vapor through them. If they're both on one cover the case is never "flushed" and accumulates sulfuric acid and combustion products.
Severe blowby is generally ring seal going away, and you already know what fixes that.
A much bigger pan volume (longer, deeper, wider), for more air not more oil, reduces the amplitude of pressure spikes, so will any extension to the valley or covers. It's only a buffer, so shape doesn't matter as long as the connection to the air under the crank is large.

Maybe thats part of my problem. 8qts in a 7qt pan.

As Jeff
Mentioned, more cubic inches need more pan volume not taken up by oil.

www.mewagner.com

My PCV valve is a Billet style from billet specialties. Too much oil in the pan is not helping either. I will be installing an oil cooler this weekend, that will get the oil level back down. I also have an oil catch can im not using that i could install or use the tall breathers that Andy posted. Moroso also has something simular.

Pictured below is my wedge motor in my other car. Two -10 lines tee'd into a breather tank mounted next to the radiator. Works great. I have a vacuum pump on my hemi, but honestly, I wish I'd just done the same thing on it.

Dave, do you valve covers have baffles in them? My small block Indy covers only had a breather in each one with no provision for a pcv valve. I drilled a hole for a pvc valve and welded in baffles in each one then plugged the breather on the pvc side. It's turned 7200 several times and never blew any oil out or had any in the pcv hose.

When it was on the dyno it picked up 3 hp with the pcv valve hooked up on back to back pulls.

Dave..8 quarts of oil in a 7 quart pan? Isn't that creating problems? Just curious here...

BIG problem try the opposite, less oil in a larger capacity pan and I run 6 qts. in an 8 qt. pan and zero issues forever........As we talked, my pcv is in a Ford truck breather full of foam which is higher up off of the valve cover helping to keep oil out of the manifold and more vapor as designed plus a home made oil separator right at the manifold............ Breather on one side, pcv on the other to pull THROUGH the engine......

Yes. I thought it was a 8qt pan when i filled it. My mistake

Yes i do have baffles and im about to add the rubber ones as well. Good to have options. Thanks

What style breathers you using?

I remember. Im also looking at running pvc on one side and double elevated breathers side by side on the other cover. Plenty of flow thru with that too. See if i can post a pic later.

Dave I honestly don't know, they were on the valve covers when I bought the engine. They are aluminum and had fittings in them for a header e-vac system. Sorry.

No problem. Think i know. I have the chrome moroso and a no name that style too. Could use a canister style like mopar or ford to, but thinking maybe just twin open breathers on one cover.

Heres something from speedway motors for $20. If i want black i just paint them. Cheap fix. Just bore another hole next to the current one and mount side by side. Function and fashion. Use pcv on other cover. Should get plenty of air flow and raised up keep oil where its suppose to be.

Another option mentioned already would be a oil breather can which i have. Just needs black paint on the cheap as well. Heres one i never seen before. Looks cool.

A little crude looking but cheap and effective:
1. big (at least 3/4") fitting in each valve cover, with a baffle inside to mask splash
2. big hose goes away from the engine sideways
3. to a big horizontal cylinder on top of the inner fender (largest diameter that allows the hood to close)
4. if possible, cylinders should drain back to the covers when stopped, otherwise a drain and hose to empty it
5. huge volume is possible: 3" OD × .060" wall cylinder 24" long is over 300" for both
6. a backfire will blow the connecting hose off, so strength is useless in the cylinder itself - no moly, no carbon fiber, just mild exhaust tubing
7. not as effective as an extension to the pan because
a. limited by hose size
b. air blowing up from the pan fights oil drain from the heads

Heres a Peterson breather that Andy suggested. Has a check valve and pricy as well. Not sure i would want a check valve there. Looks like a quality piece thou.

Really looking for inexpensive and simple. I think the open element breather is the easiest yet and on paper should work. Thanks for the ideas.

I'd be inclined to deal with the blow by before trying to crutch ring seal with a PCV system. That's not what they are for.

That said, I'd seal the engine and run your PCV system closed and run pan evacs with it. You can get a negative pan pressure doing it that way.

Not as much as with a vacuum pump but more than what you have now.

Cant run pan evac with exhaust system. Tried that already. They make pressure with rpm.

PCV hose, -4 enough or should i have -6 hose on PVC valve?

Then I'd consider a vacuum pump.

2 is a waste of time and $$$ really...........I run a K&N open breather with a home made wrap around piece of tin to limit excess oil spray...........

From what i have been told vac pumps on the street need alot of maintenance with the vanes needi g replacement often. Was gonna go that way awhile back with my sb but was talked out of it.

I agree 1 would be enough, but the kit comes with 2 for $20.

Cant believe the price of the K&N breathers. $20 more than the Peterson and i bet not near the quality.

GM and others have been using electric vacuum pumps on street cars for a long time.
On a sound 500HP engine with normal ring tension, the factory setup has worked for me.
On my Duster drag car, when it wasin the 11s & no mufflers, a pan evac worked. When I got greedy, with low-tension rings as part of the revised combo, put it in the low 10s, and added a bit of 3.5" exhaust & Bullets to meet a Db rule, the pan evac wasn't as effective, some smoke from the pipes. Changed to a regular GM electric vac pump & vented puke tank. Fixed. Sucks out of one valve cover, pulls 5" of vacuum measured at fitting on opposite valve cover.

I ended up running two PCV and two screw in breather caps, one of each on each side on my old 518 pump gas street 400 stroker motor I had a old set of Cal Custom cast aluminum valve covers on it with a single PVC and breather cap on the other side, it would push oil out of the breather cap when racing it on the weekends shifting at or above 7000 RPM I added three more breathers caps which helped but did not cure the oil pushing out the caps, adding two PVC with two caps did end up curing it
I do make and use a crankshaft scrapers also, they help I run six quarts in a stock 1970/1971 Mopar Street Hemi, 440 six pack oil pan also, I do not overfill it

Ok Cab. This is the pan i bought from you. Thought you said to use 1/2 qt over pan capacity to avoid sucking pan dry thru 1/4? Thought it was a 8qt, nope its a 7qt. So you say to use 6qts? May be main problem with oil pushing out with high rpm.

I know of a few people running those and some like em some don't but I pull 12+ in. of vacuum cruising and around 7 idling so I'll stick to this BUT, at wot the 5" is better then the 0-2 in. of vacuum a lot probably see there...........

If Moroso says that pan holds 7 quarts try running it there and watch the oil pressure in the 1/4 from the 1000 lights on
I bought that pan used so I didn't get the instruction with it, do you use a windage tray in it? If not I would

If you are sucking the pan dry on a 1/4 mile pass you have issues.

There is no POSSIBLE way to suck a pan dry like that. If the pick up is .250 from the floor of the pan (depending on the pick up) like it should be you can't suck a 5 quart pan dry in one pass.

I guess you could have some issue with oil return and the heads are holding oil it's POSSIBLE. If that's the case, the fix isn't more oil in the pan. It's to figure out how to get the oil out of the heads.

I thought the old wives tale of sucking pans dry was gone. Evidently not.

I had one of those yrs back on my sb, but decided i didn't have that bad of a problem and just went back to open breathers. Mine pulled 3 or 5" of vac cant remember. It was just more wires and another switch. I understand that ford has one thats better than the GM pump. I'm going simple with this deal, open breather on one side and PCV valve on the other. Think i'll get some stuff ordered today.

Yes, windage try in use.

Your right, that would be alot of oil to suck up in 9 or 10 seconds, but when the oil is hot and thin I'm sure alot of it ends up at the back of the pan on the launch and with some trapped up top could add up. I'm using the Edelbrock victor heads and they do seem to trap some oil on outer cover rail. Combine that with a Milodon high volume pump and that could be a problem. I will be sure to watch that gauge on first couple passes. Wont have time or money to get the 4.30 gear and spool out in exchange for a 3.73 and track loc diff, so 1/8 is what i will be running for this yr. Running out of oil in 1/8 should not be a problem thou.

I had a PCV valve on my Belvedere. Had oil leaks after a pass down the quarter. I went with the electric vacuum pump, with a catch can before the pump. Eliminated my leaks!

I have some breathers with tubes on the way. Will see how they do.

That looks like the same Moroso pan I use and I run just 7 qts in it. My dipstick reads full with 7 qts in the pan. I use a standard PCV valve in my pass valve cover and a breather on the drivers side. The hose on the breather nipple is open and draws the air into the crankcase as the hose just goes down under the brake booster and I loop it once and let it point to the firewall. I did that in case the breather would spit any oil when racing as I did not want it to spit oil on my valve cover but it does not get any oil even in that hose. My valve covers have a nice working baffle in them since no oil seems to ever spit out of the breather I use. It works great on the street as my eng pulls enough vacuum that the PCV system works fine driving on the street and I have no problems or oil leaks when I race. But I don't race alot as its only been about once a year lately. Ron





This is a better pic of the breather as its just a standard breather used on some production cars but it works fine for my setup. Ron

Ok thanks Ron. I have some of those laying around. I ordered k&n open breather with black rubber top. Thought it looked better and maybe breath better as well. Oil level is lower with the install of the oil cooler as well. Doesnt blow nearly the oil now. Think i had a combo problem.

can you plumb a pcv into a 2 in. carb spacer or should it be lower, in the maifold.

As long as its below the carb its fine.

Mine's in mt Dommy adapter in ft. and my pcv and breather are both in the ft. one on each each valve cover..........

Overfilled oil: Accidentally did that on my '79 Chevy 4x4, thought for some reason it was a 6-quart capacity instead of 5-quart. It doesn't see RPM, mostly just runs into town on occasion & shoves a plow around in winter, but there was oil coming out of it everywhere, even a puddle of accumulated mist on top of the air cleaner & finned M/T valve covers I added for humor. It runs factory breather & PCV.
This in addition to the traditional SBC habit of weeping oil at every seam, mind you.
With 5 quarts, that extra rustproofing stopped.
It's a Targetmaster crate deal, not too many miles, previous owner did that some years back.

M/E Wagner...Great PCV valve. Got one for my 440 6 bbl that was blowing oil out the breather. The PCV valve I got when I changed from stock valve covers was just one that "fit" my new aluminum fabricated VCs. Just because it fits doesn't mean it's right.
M/E Wagner PCV valve is so good I'm getting a 2nd one for another car.

A remote breather tank works pretty good on a street/strip type of engine. I wouldn't use on a daily driver since a daily driver should have a PCV, but the breather tank solves a bunch of issues on a hot street/strip car.

I use a Moroso remote tank with two inputs and drain. They are tall and skinny so you can stick them next to the radiator or on the inner fender.