Positive crankcase ventilation

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clementine

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A PCV valve is necessary, but is it enough? I have seen racers use electric vacuum pumps and putting hoses from the valve cover to the exhaust collector. Are any of you running extra PCV accoutrements? If so, are you running the 'upgrade' with a PCV valve or without? I will hopefully bring life soon to a 383 with headers to life in a 67 fastback for reference. My application will rarely see the track, but I tend to get rowdy fairly often.
 
On my 440 in the Demon I use an M/E Wagner adjustable pcv with a hose off the other bank to the air cleaner base to mimic the factory setup. The key is the pcv is adjustable as any upgrades will change the vacuum characteristics of the engine. The breather and hose comes in play when the pcv isn’t operating. The pcv is pricey but in my opinion when you drop money into an engine what’s a few bucks for something that has benefits. They have some good reading on their site. As far as a vacuum pump I can’t answer. The header evacuations may not have enough flow to work correctly on a street car. But someone with more knowledge may be more informative.


M/E Wagner Performance Products – High Performance Crankcase Ventilation Systems
 
On my 440 in the Demon I use an M/E Wagner adjustable pcv with a hose off the other bank to the air cleaner base to mimic the factory setup. The key is the pcv is adjustable as any upgrades will change the vacuum characteristics of the engine. The breather and hose comes in play when the pcv isn’t operating. The pcv is pricey but in my opinion when you drop money into an engine what’s a few bucks for something that has benefits. They have some good reading on their site. As far as a vacuum pump I can’t answer. The header evacuations may not have enough flow to work correctly on a street car. But someone with more knowledge may be more informative.


M/E Wagner Performance Products – High Performance Crankcase Ventilation Systems
with that adjustable unit, how do you decide where to set its flow?
 
They have a very detailed set of destructions. You have to take some vacuum reading at the valve then the charts in the instructions tell you where to set things. It’s pretty straight forward even for me.
 
I'd say the answer is "maybe" Remember the way they were set up originally, even on 440-6 or hemis. A pcv valve in one cover, and the opposite corner a large open hose going to the filter bonnet. This was "normally" air going inTO the engine, but under hot conditions / high RPM/ "high throttle settings" that hose became an auxiliary outlet feeding engine fumes into the air filter bonnet
 
EGR usually is sucked SHUT when engine vacuum is high (idle) and will open against a spring at anything off idle. then at WOT when vacuum is very low, it will shut again via another spring so you wont even notice its working. Trouble is our cammed up motors generate less idle vacuum than a stock camshaft so it fools the EGR into opening at idle and casuing a diluted crappy idle. Adjustable units will have the ability to set the idle vaccum leves as its baseline and then work off that. EGR is similar that it opens off idle. when they go bad (EGR valves) they tend to either open at idle (vacuum leak symptoms) or not open at all causing high NOx levels.
 
The OEM PVC system has worked great for 50 years. No need to recreat the wheel.
 
I'm running the ME Wagner unit with an oil catch filter after the unit and before the return to the intake. It cleans up the return so your motor isn't eating oil blowby. Makes fine tuning a motor easy. I called Wagner to get information, they were very helpful.
 
I also have the M/E Wagner adjustable valve (and followed the instructions)... works great.
Even with a random PCV stuck in the grommet, the first one I found at Autozone that fit, there was only about a teaspoon of oil in the oil separator after 500 miles. So I removed it - just one more source of leaks. Baffles in the valve covers is the important part. That and good rings so blowby is minimized.
 
I think you will find the Wagner PCV adjustment is to adjust for the engine's idle vacuum, not the volume of air inducted. PCV at idle adds about 3 cfm of airflow.
 
The OEM PVC system has worked great for 50 years. No need to recreat the wheel.
Oh but the guys just gotta spend 150 bucks on a PCV valve to brag about how much better they are than us lowly commoners.
 
Hi a question regarding this topic on my Street truck whid bb i run open breathing just a hose from the valve covers that runs under the car before i had breaders but it smeeld bad in the cab good or bad whidout pcv
 
A PCV valve is necessary, but is it enough? I have seen racers use electric vacuum pumps and putting hoses from the valve cover to the exhaust collector. Are any of you running extra PCV accoutrements? If so, are you running the 'upgrade' with a PCV valve or without? I will hopefully bring life soon to a 383 with headers to life in a 67 fastback for reference. My application will rarely see the track, but I tend to get rowdy fairly often.

I have a home built low restriction dual exhaust , 3 1/2'' mufflers , dumped in front of the rear axle . A pcv on the pass. side , and a pan evac on the drivers side , mostly streetcar , working very well w/ .600 lift street roller cam-----jfi
 
I think you will find the Wagner PCV adjustment is to adjust for the engine's idle vacuum, not the volume of air inducted. PCV at idle adds about 3 cfm of airflow.
There are two adjustments... one is for the idle volume, and one is for the cruise vacuum.
 
Hi a question regarding this topic on my Street truck whid bb i run open breathing just a hose from the valve covers that runs under the car before i had breaders but it smeeld bad in the cab good or bad whidout pcv
what did it smell like? gas, exhaust, or BO?:poke:(BO = body odor:poke:) Gas is your carb usually......exhaust is those gasses getting trapped under vehicle or not getting a good burn, maybe one of the others will pipe in with more possibilities.

This is the drivers side ya? and where do you run it too? breather? or....
 
Oh but the guys just gotta spend 150 bucks on a PCV valve to brag about how much better they are than us lowly commoners.

Well....I did spend another $500 more on a EFI system, not to mention the added costs of tank ....yada yada yada....I like to think of us as 'test mules' ....your welcome.:poke::rolleyes: Happy Weenie RRR!!!
 
I tried two stock PCV valves for my 273 build. Both times I had a noise coming from my motor and I traced it to the PVC valve chattering open and closed repeatedly. I attributed it to my cam/timing setup as when I removed the valves the noise stopped. That led me to the Wagner product and no more noise.
 
Ok, new rules. You can't spend your own money on any upgrades if it hurts someones feelings. :rofl:
 
Ok, new rules. You can't spend your own money on any upgrades if it hurts someones feelings. :rofl:
Nobody said that, genius. I just made the point that I will not drop 100 plus bucks on a PCV valve. You go right ahead.
 
In the beginning I was attempting to look as stock as possible, but that is impossible for my skill level at this point. I will start with a regular PCV and keep that area in mind as a possible problem. Saying that, everything on this car cant be eliminated as a possible problem. Im hoping for a good startup with trackable problems and having this conversation with ya'll has given me more insight to the small things that make a great ride.

THANKS FABO!!!!
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