PCV Adapter

[cwcars88]

OK, that makes sense, the carb may be pulling more air but wouldn't the most pull be coming threw the air filter and not threw a small line to the oil fill tube.

Why not just leave the oil fill cap vent open or would that put to much air into the manifold and lean out the carb?

Wayne

[jd52cranbrook]

This is why you seal the oil fill tube and take air from the air filter.

Hope you dont mind me quoting you Tim

on this engine by modifying your draft tube and inserting the PCV unit there and routing to mainifold vacuum and at the same time modifying your oil fill tube to that of one with a seal to the tube, integral filtering mesh to trap oil mist and routing this to the intake filter by way of tube...you have a closed system..backfire protection in both places (dual filters on the fresh air intake side and the PCV valve on the intake manifold side)

at idle you will want almost full restriction of the PCV and under load where the engine is working the hardest and subject to higher by-pass pressures you will have greater flow to releive the by-pass pressure..the whole idea is to prevent emissions into the atmosphere..emissions in this case is not only just the hydrocabons of unburnt fuels past the piston rings, but the heated oil mist vapors out of gasket and seal lips on rotation parts of the engine keeping oil from the road and hopefully still in your engine lubing as it should. A faulty PCV can and will cause high oil consumption by allowing the pressure to evacuate through seals and gaskets taking vaporozied oil along with it..the "crud", build up of oil/dirt along gasket lines on these old engine are classic example of the residue of vapor by-pass..oil consumption on a long trip is usually your first indcator of a faulty/weak PCV..

[aero3113]

I finished it up today, here are some pics.

[jd52cranbrook]

Good work

I have not seen a head that still had the rear heater hose nipple in tact in a while.

[Don Coatney]

Good work

I have not seen a head that still had the rear heater hose nipple in tact in a while.

I first used the original Desoto nipple on my engine. Then replaced it with a ball valve so I could shut the hot water off to my heater in the summer. My original Plymouth head had a shut off valve.

[aero3113]

Don, I see you have a grounding strap hooked up. Where do you have it hooked up to on the opposite end?

[Don Coatney]

Don, I see you have a grounding strap hooked up. Where do you have it hooked up to on the opposite end?

[aero3113]

Another new project for me,thanks Don

[BeBop138]

JD,Aero,Tim--- ok I got the general idea on the set-up. Mine is from the draft tube to intake---do you have to do the line from the oil fill tube to air cleaner? With my twin Carter-Webers it may be difficult to run a line to the air cleaner and would you have to run a line to both carbs----plus what PCV do you use----part# or application the valve fits. Maybe Don could say---we run close to the same cam and carbs............Thanks......Lee

[aero3113]

JD,Aero,Tim--- ok I got the general idea on the set-up. Mine is from the draft tube to intake---do you have to do the line from the oil fill tube to air cleaner? With my twin Carter-Webers it may be difficult to run a line to the air cleaner and would you have to run a line to both carbs----plus what PCV do you use----part# or application the valve fits. Maybe Don could say---we run close to the same cam and carbs............Thanks......Lee

That is how I had mine set up at first. But I was told that non filtered air is being drawn in the engine if it is set up like that. If you hook it up to the air cleaner it is now a closed system. The valve that I used was from Vintage Power Wagons, I do not have a part number. I also got the block adapter from them. I think they call it a crankcase breather valve not a PCV because it does not work the same as a PCV (Not sure how it works but thats what they told me)

[PatrickG]

I guess I'll chime in too and add to the confusion.

I have my PCV set up with the vintage power wagons little cast piece (not valve) to replace the road draft tube.

(I have no pictures of my own set up so I'll steal from someone else...)

The piece looks like the same one aero3113 had in his first picture:

I have a pcv valve screwed into that piece, and a line run into the carb port.

No line going from the fill tube to the air cleaner, but instead a filtered oil fill cap/breather.

Edited May 3, 2010 by PatrickG

[Powerhouse]

the sealed setup i ran caused a constant leak out the dipstick hole...bad rings maybe? too much blow by? I have the oil fill cap removed now with rubber tube going out under the master cylinder area...creates a nice yellowish drip of slime after a drive...

[jd52cranbrook]

JD,Aero,Tim--- ok I got the general idea on the set-up. Mine is from the draft tube to intake---do you have to do the line from the oil fill tube to air cleaner? With my twin Carter-Webers it may be difficult to run a line to the air cleaner and would you have to run a line to both carbs----plus what PCV do you use----part# or application the valve fits. Maybe Don could say---we run close to the same cam and carbs............Thanks......Lee

I ran my line to only one carb of my twin set up. I do it to get clean air to the crankcase. Plus it keeps it a closed system. Although VPW does not call it a PCV, it acts in general the same way. I used their set up.

The main good thing about running a closed system, besides saving the environment a bit, is,,,,,,,,,,,;

If you put stacks on your carb air filters, and exhaust, you run your car in the rivers and lakes.,,,,,,,

[jd52cranbrook]

the sealed setup i ran caused a constant leak out the dipstick hole...bad rings maybe? too much blow by? I have the oil fill cap removed now with rubber tube going out under the master cylinder area...creates a nice yellowish drip of slime after a drive...

Something is plugged up for sure, or installed in reverse. My bet is not bad rings, as you would have other symptoms, like lack of any power.

[BeBop138]

If I leave mine with the PCV coming from the draft tube to the intake and nothing else---will it hurt anything---does this make it an open system?

[jd52cranbrook]

I am not sure how much draft you will get coming from the air cleaner itself. You might try going straight to the intake manifold, but check for a vacume leak that is might cause.

And yes, its a open system, you can't take your car in the water..

[JBNeal]

Orientation of the PCV valve depends on the type of valve. Some older valves have an internal spring, so they can be installed vertically or horizontally. Vacuum that can overcome the spring force will open the valve, and when vacuum drops, the spring closes the valve. These valve were hard to test without a vacuum gauge.

Later PCV valves are much simpler designs, and are akin to a simple ball-check valve. Vacuum pulls the valve off of its seat, and gravity re-seats the valve since there is no internal spring. This type of check valve can only be mounted vertically so that it can function properly, and can be tested by shaking the valve & listening for the rattling noise of the freely floating check valve.

The 'closed' system described is a bit of a misnomer as the modified oil filler vent caps do not have a true sealing surface to the oil fill tube. Closing off the oil filler vent vastly reduces the crankcase exposure to the environment, but doesn't completely seal it off. Chrysler's service bulletins regarding the installation of a PCV system on the flatheads shows the oil fill tube changed to accept a vent-less oil fill cap + gasket, as well as a port for venting to the air cleaner. If the oil fill tube is sealed off or the oil filler vent cap is sealed off without a provision for venting to the air cleaner, excess blow-by pressure will likely try to escape through the main seals or the dipstick tube.

One thing that I have realized after studying the PCV discussion threads is that much like today's modern gasoline motors, the flathead requires two PCV sources, with one source using a PCV valve to the intake area and one routed from the crankcase to the air cleaner. At idle, the engine produces high vacuum at the intake, which opens the PCV valve to allow induction of blow-by gases. As vacuum drops with the increase in engine speed, the PCV valve closes, allowing blow-by gases to be metered by the PCV valve & excess pressure to be vented to the air cleaner. This subtle balancing act of the PCV valve on crankcase gases allows the engine to burn as much combustibles as possible, as well as remove moisture from the crankcase vapors.

When adding a PCV system to the flathead, the carburetors need to be reset to account for the controlled vacuum leak being added to the induction system. Otherwise, idle speeds will more than likely be accompanied with an engine stall unless partial choke is applied.

[jd52cranbrook]

ummmmmm with respect

The closed system is not a misnomer. If you look at the Vintage Power Wagon set up you see it is a capped cover. I have one here in my hand. Instead of using the bulky top, I just covered my vent holes on my existing fill tube cap. It may bubble underwater, but it is more than sufficient to seal off non pressurized air from the outside.

Keeping it a closed system, or close to it, requires no additional carb adjustment other then at the initial install. This is assuming there is adequate cap at the dipstick too. I've ran over 20,000 miles on mine with no start out stall whatsoever.

Update...... I took the fill cap all apart, and it looks there is a small area for vented air to get in, but it is positioned to prevent water from coming in if submerged for short periods of time.

Edited May 6, 2010 by jd52cranbrook

[aero3113]

When I started up my car for the first time with the PCV installed correctly it would stall. I adjusted the idle screw and all has been good.

[Powerhouse]

any part number on the VPW pcv valve? How do you get replacements? I think my valve must be incorrect.

[jd52cranbrook]

I went to their web site,

http://www.vintagepowerwagons.com/

part is not listed, but you can call. Remember this is a non spring type, and I am pretty sure used piece. There are no parts to wear out so you just keep clean and should be good to go......

But I am pretty sure any generic type would work.

[Powerhouse]

Thanks..i'll be calling them soon.

[BeBop138]

Here is a pic of the filler tube I will be using---I grafted the old with the new. The new is a tube from a Chrysler van, it has the yellow/black theme I got going in the engine compartment. The only problem I can see is that it will no longer have the bracket holding it to the block. It fits tight at the bottom but I am concerned without the bracket it may loosen up and leak. I thought I would use a good dose of Ultra Black sealer and give it a good rap into the block---any thoughts on making sure it seals...............Lee

[BeBop138]

ummmmmm with respect

The closed system is not a misnomer. If you look at the Vintage Power Wagon set up you see it is a capped cover. I have one here in my hand. Instead of using the bulky top, I just covered my vent holes on my existing fill tube cap. It may bubble underwater, but it is more than sufficient to seal off non pressurized air from the outside.

Keeping it a closed system, or close to it, requires no additional carb adjustment other then at the initial install. This is assuming there is adequate cap at the dipstick too. I've ran over 20,000 miles on mine with no start out stall whatsoever.

Update...... I took the fill cap all apart, and it looks there is a small area for vented air to get in, but it is positioned to prevent water from coming in if submerged for short periods of time.

JD, what did you use to seal your dipstick tube...Lee

[jd52cranbrook]

My original was broken off long before I got the car I guess. I just used one from a auto parts store, forget which one now. It has a cup on it to cover the tube. Unless your intent to drive the car underwater I don't think the minimal amount of air, if any being sucked through the tube is going to upset the air flow.