Opinion on PCV valve for flathead?

[BobM]

Any thoughts on the value of running a PCV valve on a flathead? If I change oil every thousand miles is there any benefit in running one?

[51 MERC-CT]

Don't know if there are any noticeable benefits but it sure gets rid of the flathead blowby smell coming out of the breather and road draft tube

[BobM]

Originally Posted by 51 MERC-CT

Don't know if there are any noticeable benefits but it sure gets rid of the flathead blowby smell coming out of the breather and road draft tube

Which PCV valve did you use, I think I saw where a PCV valve from a Jeep would fit into the '49-'53 intake?

[Ralph Moore]

I love the smell of blowby in the morning, it smells like Victory!

[36tbird]

Bruce has been nice enough to point out the merits of a PCV many times on this forum and the HAMB. If I have it correct, the military flatheads had them and the biggest benefit of having one is burning off the moisture in the oil and that keeps sludge from forming. I have one on my 8BA from the gent who sells the neat kit to do this on E-bay. Right now I have a Southwind heater vacuum plate under my carb that provides the suction. However, my plan is to run the tube from the PCV to the air cleaner and vent the crank case that way. I think that will allow me to keep my manifold vacuum higher and use it for the distributor vacuum source.

[ford1]

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the problem with running the pcv to the air cleaner is that there is not enough vacuum or suction to make it work at idle, off the carb or manifold it works good at an idle and is restricted when at hi way speeds, the one to the air cleaner works good at hiway speeds due to the extra suction by higher engine rpm's

[Karl Wolf]

PCV valve in proper form goes into intake manifold vaccuum, I picked out a pcv valve by finding one that is original to another engine about the same displacement, with the end I want to plump to (1/4" pipe thread) The air cleaner is the source for air into the crankcase... I could look to see what it was if anyone is interested... Karl

[Chris Nelson]

I have found that the Borg Warner #382 PCV valve and a Ford OHV grommett for a PCV valve are the best combination in an 8Ba intake manifold. The specs are;
Closed at idle 16-18 in Hg (Inches of Mercury(Hg) vacuam)
Floats at 8-10 in Hg
Open at 1-6 in Hg

[Newc]

Hi all; I put a PVC on my 59 A by welding up the oilpan vent and using a threaded [pipe] fitting there, then a hose to a carb base vaccum plate. No more seal leaks and the breather worked great, really cleaned up the engine. Newc

[ford1]

the air cleaner does not put air into the crank case, it pulls air out of there to remove fumes, the road draft tube allows air into the crank case to vent it if its still hooked up, if not you need a ventilated oil cap to let air into the crankcase

[flatjack9]

The crankcase air left the engine by way of the road draft tube. Air entered through the ventilated oil fill cap. As far as the need for it, I don't happen to have one on mine and after 17 years of use and around 50,000 miles there is absolutely not even a hint of any sludge formation. I'm sure it's due to the vastly superior oils we have today.

[ford1]

flatjack, your right, thats the way the originals worked, and it let the fumes out under the car at idle, but when you hook up a pcv with the original draft tube the air is pulled in thru it, the best way is to plug the vent tube and use a pcv valve off the carb or manifold with a vented oil cap, modern engines use 2, one for each valve cover, one from the manifold and one coming from the air cleaner and using a vented oil cap

[David J]

A couple things to consider . If you have a motor that is meant to have a drain pipe in the rear main and you don't have one or if it is not long enough to stay immeresed in oil at all times you will be sucking all that wonderful clutch debris and whatever else is getting into the bellhousing cavity INTO your motor . And if you have this going on and also have a vented pan you will get all the dust and road crap into your motor . The main thing to remember is if you run a PCV you need to let filtered air into your motor. Many ways of doing this and yes you're talking about later motors but the principal is the same - you will be sucking debris into your motor . There isn't any harm in a PCV setup just make sure you filter the air going in . My 3.14 cents worth . David J

[flatjack9]

David is right on. I would not want to be drawing air into the engine from the road draft tube. Draw it from the air cleaner.

[Mike in AZ]

hey, 51 Merc-CT....you running 12V on your avatar??...pretty cool....Mike

[Jack E/NJ]

36tbird>>>my plan is to run the tube from the PCV to the air cleaner and vent the crank case>>>

ford1>>>the problem with running the pcv to the air cleaner is that there is not enough vacuum>>>the one to the air cleaner works good at hiway speeds due to the extra suction by higher engine rpm's>>>

As Lou knows, I'm running a simple reverse-flow no-valve PCV. A tube filled with stainless steel mesh runs from the air-cleaner cannister to the oil-filler stand. A fine air filter screen is also wrapped several times around the crankcase vent to prevent road debris from entering the crankcase. The main purpose of the mesh-filled tube is to prevent backfires as well as catch entrained oil droplets. Lou says he's found a PCV valve that works on low air-cleaner vacuum that should also serve a similar purpose.

Jack E/NJ

[Lowsquire]

here is another advantage of a PCV on an early 24 stud motor, My 99A has a labrinthe rear main (no rope) and without the PCV would always drip oil due to being forced out by positive crancase pressure, which the vacuum PCV system reduces to a point where I dont get an oil patch when I park. I concur that,with the improvement in oil formulation and changing it regularly, sludge build up shouldnt be an issue.

[DirtyDan]

I am running an 8BA w/ an early Eddie Meyer intake. I capped off the road draft tube w/ an elbow fitting and then drilled a hole into the center runners of the intake and installed a threaded PCV valve. It really cut down on the blow by, and it is hidden.

[36tbird]

Here's a picture of my untested PCV set up for my 59A.

[51 MERC-CT]

Could be wrong but it looks to me like all you are doing is sucking in (with what little vacuum is available at the air cleaner) primarily fresh air.

[36tbird]

Nope, the back scoop will be blocked off. Just on there for looks. Sorry, I should have pointed that out. Outside air will be coming in from oil pan vent. Also, I am running a tube down inside the filler hole so that I will give priority to crankcase not lifter valley but that probably doesn't matter given the holes in the lifter valley that go to the crankcase.

[flatjack9]

How are you going to filter the incoming air?

[296 V8]

Originally Posted by DirtyDan

I am running an 8BA w/ an early Eddie Meyer intake. I capped off the road draft tube w/ an elbow fitting and then drilled a hole into the center runners of the intake and installed a threaded PCV valve. It really cut down on the blow by, and it is hidden.

I did one exactly like this and it sucked up oil and smoked real bad

I removed the hose and built a baffle (attached to the gasket) over the valve and just pulled the blow by from the valley.

A big part of a PCV valves job is to save the engine from exploding if it backfires…..it is a check valve.

[V8 Bob]

Originally Posted by ford1

flatjack, your right, thats the way the originals worked, and it let the fumes out under the car at idle, but when you hook up a pcv with the original draft tube the air is pulled in thru it, the best way is to plug the vent tube and use a pcv valve off the carb or manifold with a vented oil cap, modern engines use 2, one for each valve cover, one from the manifold and one coming from the air cleaner and using a vented oil cap

You never want to pull air into the engine through the road draft on any engine. Why would you? On 8BA's, the pcv replaces the road draft tube at the intake. On the '35-'48s, closing up the pan vent and adding the pcv there, as Newc did, is probably the best on these engines. The engines will now vent as designed, even though the air flow inside differs.
Air can be drawn in through the stock oil fill cap, or from the air cleaner, as late 60's cars began to do. (this is known as a "closed" pcv system).

No late model car uses two pcvs that I have ever seen. What may look like a pcv is simply a fitting off the sealed valve cover cap or grommet that goes to the air cleaner. The actual pcv always is plumbed to manifold vacuum. There would be no air flow running two pcvs.

[V8 Bob]

Originally Posted by 36tbird

Nope, the back scoop will be blocked off. Just on there for looks. Sorry, I should have pointed that out. Outside air will be coming in from oil pan vent. Also, I am running a tube down inside the filler hole so that I will give priority to crankcase not lifter valley but that probably doesn't matter given the holes in the lifter valley that go to the crankcase.

Not sure what you're logic is on trying to pull air into the 59 pan vent, but you do know that the early pan vents ('35-'48) go directly to the valve chest, not the crankcase, like the later 8BAs? What you describe above will give priority to the valve chest.

[36tbird]

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Here's my thinking. Air coming in from the oil pan vent with a foam filter around it. That air goes up into the lifter valley. There are holes in the lifter valley that go down to the crank case, right? Now, with the stock type tube that goes down from the fuel pump tower mount into the block at the rear of the lifter valley and my oil filler cap unvented, the air cleaner tube with the PCV will be sucking on the crank case air. This is the same venting system route as stock, except in reverse.

Jack E/NJ has been running with this sort of set up except that he is not using a PCV. Hopefully the PCV I chose will work OK and I think by having it mounted horizontally the little check ball in there is more sensitive to the lower vacuum I am using from the air filter. That is, if it were mounted vertically, it would have gravity to overcome to move the marble. We'll see.

[V8 Bob]

Originally Posted by 36tbird

Here's my thinking. Air coming in from the oil pan vent with a foam filter around it. That air goes up into the lifter valley. There are holes in the lifter valley that go down to the crank case, right? Now, with the stock type tube that goes down from the fuel pump tower mount into the block at the rear of the lifter valley and my oil filler cap unvented, the air cleaner tube with the PCV will be sucking on the crank case air. This is the same venting system route as stock, except in reverse.

Jack E/NJ has been running with this sort of set up except that he is not using a PCV. Hopefully the PCV I chose will work OK and I think by having it mounted horizontally the little check ball in there is more sensitive to the lower vacuum I am using from the air filter. That is, if it were mounted vertically, it would have gravity to overcome to move the marble. We'll see.

My main question is what possible advantage is there reversing the vent system air flow, and taking in air near the road through the early pan vent or 8BA draft tube?

[Roger/Sacramento]

The purpose of this discussion is to remove blowby from the valley/crankcase. I don't like the idea of running the dirty air into the intake manifold. You also must consider the size of and maintenance of a PCV valve. I have an idea of running a tube from the draft tube location to a fitting on the exhaust pipe extension (past the exhaust manifold). The idea of lubricating the top cylinders is better done with Marvel Mystery Oil in the gas tank. My idea eliminates the possibility of wrong engineering.

[36tbird]

The advantage is not drawing manifold vacuum off for a PCV. Also, I am not running a long tube from the air cleaner to the oil pan vent. I want to preserve my manifold vacuum for the Chevy distributor that I will be running. My feeble brain tells me that keeping your manifold vacuum as high as possible will add to the efficiency of your engine. Some people hang out at pool halls, I'll be hanging out trying to tune my flathead for the best efficiency using the old Strombergs.

You imply that "taking in air near the road" is a problem. I'm not lowering the front of this project that much where I think there would be some issues. Also, I think that there is enough air turbulence around front sheet metal, frame crossmembers, radiator, etc and our ground speed is not so high that a low pressure area around the pan vent would cause ambient air to not be available.

[BobM]

Originally Posted by 36tbird

Here's my thinking. Air coming in from the oil pan vent with a foam filter around it. That air goes up into the lifter valley. There are holes in the lifter valley that go down to the crank case, right? Now, with the stock type tube that goes down from the fuel pump tower mount into the block at the rear of the lifter valley and my oil filler cap unvented, the air cleaner tube with the PCV will be sucking on the crank case air. This is the same venting system route as stock, except in reverse.

Jack E/NJ has been running with this sort of set up except that he is not using a PCV. Hopefully the PCV I chose will work OK and I think by having it mounted horizontally the little check ball in there is more sensitive to the lower vacuum I am using from the air filter. That is, if it were mounted vertically, it would have gravity to overcome to move the marble. We'll see.

Would braking and acceleration effect the check valve if mounted horizontally?

[V8 Bob]

Originally Posted by 36tbird

The advantage is not drawing manifold vacuum off for a PCV. Also, I am not running a long tube from the air cleaner to the oil pan vent. I want to preserve my manifold vacuum for the Chevy distributor that I will be running. My feeble brain tells me that keeping your manifold vacuum as high as possible will add to the efficiency of your engine. Some people hang out at pool halls, I'll be hanging out trying to tune my flathead for the best efficiency using the old Strombergs.

You imply that "taking in air near the road" is a problem. I'm not lowering the front of this project that much where I think there would be some issues. Also, I think that there is enough air turbulence around front sheet metal, frame crossmembers, radiator, etc and our ground speed is not so high that a low pressure area around the pan vent would cause ambient air to not be available.

If you ever connected a vacuum gauge to the manifold, and measured the level before and after connecting a properly sized pcv, you would realize there is NO loss of measurable vacuum. You're concerned about something that doesn’t exist.

Along with the worst area to pull air into the engine, the 8BA draft tube and earlier pan vent act like pitot tubes, because of the partial vacuum developed by air flow when vehicle speeds reach about 30 mph and higher. You're not going to get near the needed amount of air into the engine by this "reverse engineering", if any at all, during high speeds.

With no disrespect intended, some things are not a good idea, and this is definitely one of them. Adding a pcv in place of the draft tube or pan vent is the best and simplest way to provide ample and beneficial ventilation in pre-pcv vehicles.

[Ronnie]

This should clear up some pcv questions. Note there are two systems to choose from.

R

[Jack E/NJ]

V8 Bob>>>My main question is what possible advantage is there reversing the vent system air flow, and taking in air near the road through the early pan vent or 8BA draft tube?>>>

The advantage is positive as opposed to passive crankcase ventilation.

Roger/Sacramento>>>You also must consider the size of and maintenance of a PCV valve.>>>You also must consider the size of and maintenance of a PCV valve. I have an idea of running a tube from the draft tube location to a fitting on the exhaust pipe extension (past the exhaust manifold). The idea of lubricating the top cylinders is better done with Marvel Mystery Oil in the gas tank.>>>

As Ronnie suggests above, you may choose to use a valve like Lou did or NOT. I chose NOT to use a valve in the tube connecting the pump stand to the air-cleaner cannister. This tube is filled with stainless steel mesh to prevent backfire into the crankcase and retard oil mist into the air cleaner. This is in fact similar to the first low-vacuum positive ventilation systems in the late 50s before the elimination of the open-crankcase draft tube and before the introduction of the closed-crankcase high-vacuum PCV valve. This early positive ventilation system was still used in combination with the closed-crankcase PCV valve well into the 70s and 80s because it works when the PCV valve doesn't at near WOT when blowby is greatest.

Roger's idea of venting the crankcase with an exhaust venturi seems like a good one.
Jack E/NJ

[flatjack9]

Originally Posted by 36tbird

Here's my thinking. Air coming in from the oil pan vent with a foam filter around it. That air goes up into the lifter valley. There are holes in the lifter valley that go down to the crank case, right? Now, with the stock type tube that goes down from the fuel pump tower mount into the block at the rear of the lifter valley and my oil filler cap unvented, the air cleaner tube with the PCV will be sucking on the crank case air. This is the same venting system route as stock, except in reverse.

Jack E/NJ has been running with this sort of set up except that he is not using a PCV. Hopefully the PCV I chose will work OK and I think by having it mounted horizontally the little check ball in there is more sensitive to the lower vacuum I am using from the air filter. That is, if it were mounted vertically, it would have gravity to overcome to move the marble. We'll see.

Your problem is going to be that you will get no flow through that PCV valve because there is no vacuum to operate it. The PVC valve consists of a variable diameter pintle and a spring both of which are calibrated to the engine it is used on. It makes no difference if the valve is horizontal, vertical or upside down. The spring needs the vacuum working against it to open the valve. When the engine is off, the spring pushes the pintle shut and this is the position yours will be in. Install a vacuum gauge inside the air cleaner and you will see where your problem lies. Jack's system works because he doesn't have a valve to block any flow.

[36tbird]

Have you ever sucked on a PCV? The one I got allows air through without any noticeable resistance. However, if you blow into it to simulate a backfire, it slams shut. That is it's real purpose to be able to slam shut. I feel that the intake vacuum in an air cleaner will be more than adequate to keep the PCV open. Jack's idea of reverse flow that I stole to make up my set up, subscribes to the KISS theory and does not need to be over thought.

[Butch11443]

I use a pvc on an 8BA type intake where the road draft tube is. I have a closed oil fill cap with the tube going to the bottom of the air filter. Simple and works excellent.
Butch

[36tbird]

Butch, have you been running that set up very long?

[51 MERC-CT]

Originally Posted by Butch11443

I use a pvc on an 8BA type intake where the road draft tube is. I have a closed oil fill cap with the tube going to the bottom of the air filter. Simple and works excellent.
Butch

Do you have a vacuum source going to the pcv valve? If so to where?

[Jack E/NJ]

Butch>>>I use a pvc on an 8BA type intake where the road draft tube is. I have a closed oil fill cap with the tube going to the bottom of the air filter. Simple and works excellent.>>>

IMO, Butch's setup is a proper way for achieving positive ventilation in a closed-crankcase using a PCV valve. To avoid altering the pan's draft vent to accomodate the valve, the valve might also be re-located at the end of the dipstick tube with a rubber grommet and the pan vent simply plugged. The valve would then be closer to manifold vacuum and easily removed for checking oil level.

Jack E

PS to Lou: If you want to try a closed-crankcase PCV, you could keep your setup as-is. Just add another valve on the dipstick tube to manifold vacuum, plug the pan vent, and either keep your present valve to the pumpstand or fill the tube with mesh to prevent backfire.

[fortyfords]

I think its a good idea.

[Kahuna]

36Tbird
I think it'll work just fine

[santino2010]

hello there im trying to also run pcv on my 239 flatty but im using stock intake manifold.
can anyone send me more specific photos of how to do this step by step thank you

[2935ford]

I installed one on my 8BA in my '35 slantback.......goodbye blowby.
Worked as intended.

[santino2010]

Yes but I would like to see how to modify my intake manifold if anyone has pictures that would be helpful thanks

[Fourdy]

This has worked for me.







Fourdy

[Mart]

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No disrespect, Fourdy, but aren't you just sucking fresh air up through the road draft vent?

Not trying to be clever, just wondering..

Mart.

[Fourdy]

Hey Mart, you have to work a lot harder than that to cause me any grief. LOL I don't have a road draft tube. The manifold is one of the goofy offy type that wasn't bored for the draft tube. I called offy and was told it just saved money to use one blank for both styles.

Fourdy

[JSeery]

Not sure I understand the tube through the valley, why not pull the air out of the valley itself (with an oil baffle of course)?

[V8 Bob]

Originally Posted by Mart

No disrespect, Fourdy, but aren't you just sucking fresh air up through the road draft vent?
Not trying to be clever, just wondering..Mart.

Originally Posted by JSeery

Not sure I understand the tube through the valley, why not pull the air out of the valley itself (with an oil baffle of course)?

I think there may be some confusion on early and late flathead ventilation.
On the '35-'48s, air enters at the rear, moves down into the crank case, up into the valve chest and then down the vertical tube which leads directly to the pan (road draft) vent.
On the 8BA, air enters at the front, moves through the valve chest and down into the crank case, then up through the vertical tube and into the road draft pipe through the intake.

[JSeery]

Originally Posted by V8 Bob

I think there may be some confusion on early and late flathead ventilation.
On the '35-'48s, air enters at the rear, moves down into the crank case, up into the valve chest and then down the vertical tube which leads directly to the pan (road draft) vent.
On the 8BA, air enters at the front, moves through the valve chest and down into the crank case, then up through the vertical tube and into the road draft pipe through the intake.

Ok, but not sure with a PVC why you can't vent off of about anywhere. You are releasing crankcase pressure and exhausting blow by. Not sure it is important to follow a specific path, although good circulation would help. How was Ford's PCV system setup, that might be a good example?

Edit: On second thought that is not going to help much! Ford's PCV would have been in the war years and a 59a style block.

[Fourdy]

I guess I'm thinking that fresh air in through the oil fill, thru the valley into the pan then forward to the capped stand pipe in the valley, thru the tube to pcv then to manifold vacuum to help burn some of the bad stuff all up. Always ready to learn.

Never THE WAY, just the way I did it.

Fourdy

[JSeery]

Sounds good, I run a 59a with stock ventilation, so what do I know!

[V8 Bob]

Originally Posted by JSeery

....How was Ford's PCV system setup, that might be a good example?
Edit: On second thought that is not going to help much! Ford's PCV would have been in the war years and a 59a style block.

Ford installed a pcv in the intake manifold near the area of the front stand pipe, pulling the fumes up and then plumbed to the carb base (manifold vacuum), instead of allowing them to exit down the stand pipe and out the pan vent, according to pictures I've seen of WW11 military flatheads.

[JSeery]

Originally Posted by V8 Bob

Ford installed a pcv in the intake manifold near the area of the front stand pipe, pulling the fumes up and then plumbed to the carb base (manifold vacuum), instead of allowing them to exit down the stand pipe and out the pan vent, according to pictures I've seen of WW11 military flatheads.

I thought I had an article on that whole set up somewhere, but I can't find it!

[blucar]

From my prospective, based on many applications of PCV systems on pre "SMOG" engines that I have done, I have formed the opinion that very few people really have a clear grasp on how a Positive Crankcase Valve system works.
The object of a PCV system is to draw clean, filtered air into the engine, circulated it through the engine, utilizing engine vacuum, then introduce the oil contaminated air into the intake system where it is blended with the air/fuel mixture and is burned off.
The introduction of the PCV system in 1963, eliminate 90% of the "SMOG" vapors that the internal combustion engines emitted via the open road draft devise (s) that had been in use since the invention of the internal combustion engine.
Many years ago I encountered the PCV system that Ford used on the '64 Y-Blocks. This system used a little dome shaped cap that replaced the '63 and earlier road draft tubes, the cap had a fitting for a 3/8" hose, the hose was attached to a PCV that was threaded into the intake manifold.
Air was drawn into the crankcase via the filtered oil fill cap, the vacuum then pulled the air flow through the block/valve chamber and into the intake manifold, to be burned off.. No blow by, no crankcase pressure, just a well ventilated clean engine.
GM used a variation of the same domed adapter to eliminate the road draft tubes on the '63 SBC's, the only difference was GM used a PCV that plugged into a valve cover via a rubber grommet.
Some Y-Blocks have a crankcase breather on the lower left side of the block, this could be compared to the pan breather on the left side of many of the early flathead engine.. The block/pan breather has to be blocked off in order for a PCV to work properly.
OK now the problem is, how do you utilize a simple system like the Y-Blocks? Very simple, don't try to reinvent the wheel, and don't over engineer the system.
The 8BA/8CM engines are the easiest, eliminate the road draft tube from the front of the engine, fabricate something to take it's place to which a 3/8" hose can be attached. Find a good vacuum source, below the throttle plate (s).. Use a PCV that is from an engine that is close to the CID of the engine being modified.
From my way of thinking the system would work best if the air was drawn in from the rear of the engine, maybe via a modified early V8 modified fuel pump stand with a filtered cap on top.
I would think that if the vacuum is pulling vapors from the block via the old road draft port, and the original oil fill pipe was left open, circulation of the vapors would not be good.. Ya know the shortest distance between two points..
The early flatheads are more of a challenge because of the intake manifold would require drilling and threading of a hole that the PCV could be threaded into, then a vacuum source has to be obtained..
The WWII military vehicles used a closed crankcase, i.e. PCV because many of them were equipped to keep water out of the engine, because they "forded" water deeper than the engines, the breathers were extended to above the windshield, and/or they were intended for desert use in extremely dusty conditions...

[V8 Bob]

Originally Posted by blucar

.......The 8BA/8CM engines are the easiest, eliminate the road draft tube from the front of the engine, fabricate something to take it's place to which a 3/8" hose can be attached. Find a good vacuum source, below the throttle plate (s).. Use a PCV that is from an engine that is close to the CID of the engine being modified.
From my way of thinking the system would work best if the air was drawn in from the rear of the engine, maybe via a modified early V8 modified fuel pump stand with a filtered cap on top.
I would think that if the vacuum is pulling vapors from the block via the old road draft port, and the original oil fill pipe was left open, circulation of the vapors would not be good.. Ya know the shortest distance between two points.

The 8BA intake gasket isolates and directs the vertical stand pipe directly to the road draft tube, allowing the incoming fresh air (through the oil fill) to flow through the valve chest and down into the crank case.

[johnh7]

My 38 pickup has a road draft tube on the oil pan. Does anyone have plans showing how they installed a PVC on the road draft tube? I already purchased a vented plate that installs under the carburetor. I will run a tube from the PCV to the vent in the plate. I should get good suction from there.

[Ol' Ron]

Fourdy
What transmission are you using??

[sidevalve8ba]

This is the PCV routing that I came up with for my 8BA. I removed the crankcase vent pipe from the front of the intake. I then took an appropriate sized freeze and drilled an appropriate sized hole for the PCV valve grommet. I pressed this freeze plug grommet into the hole for the crankcase vent tube. The PCV valve is installed there and a smog hose run to the existing hole at the base of the rear carb on this Edelbrock intake. Seems to work fine for me.





The system breaths through the vented cap on the oil filler tube. I am always open for suggestions so if you see a way I can improve upon this system let me know.

[Ross F-1]

Originally Posted by sidevalve8ba

The system breaths through the vented cap on the oil filler tube. I am always open for suggestions so if you see a way I can improve upon this system let me know.

I had virtually the identical system on my truck for 5 years. Never any problem, until I installed an air/fuel monitor on the truck. I could see that to get it to idle, I had the mixture so rich it killed economy at cruise. If I'm not mistaken you also have a Ford 5.0 / 302 PCV, Fram #FV294? I switched to a Fram FV306, which is for a lot of Toyota engines. It provides enough PCV flow to work fine, but not so much as to upset the carb.

[Fourdy]

O'l Ron,
The trans is a 200-4R. The car is pretty light so cruises nicely. Makes me want to take the C4 out of my 40 and replace it with the 200-4R

[JSeery]

That doesn't look stock! Reminds me of some Ts running around when I was in high school. Looks nice.

[pendeloque]

Originally Posted by Chris Nelson

I have found that the Borg Warner #382 PCV valve and a Ford OHV grommett for a PCV valve are the best combination in an 8Ba intake manifold. The specs are;
Closed at idle 16-18 in Hg (Inches of Mercury(Hg) vacuam)
Floats at 8-10 in Hg
Open at 1-6 in Hg

I have an 8BA, 1951. When I got it someone had removed the road draft tube and simply put in a pcv valve with a hose leading down below the engine (open). I did not know everything I should have, at the time. I had oil leaks around the gaskets, and oil pushed up thru the oil dip stick tube. That is what led me to understanding blow-by crankcase pressure. I then bought a simple pcv valve from NAPA attached a hose to it and connected it to the vaccuum input beneath the carb (initially for the windshield wipers, now electric). That was a few days ago. So I do not know if I have done the right thing yet. Too soon to tell. However, I have read everything on the internet about pcv oil catch cans and I am looking to install one between the pcv valve and the intake manifold hose input. Must I have a special pcv valve or is the universal one sold at NAPA OK. Is there enough vaccuum to pull thru the oil separator. I really need all the suggestions I can get. Many thanks. Peter

[51 MERC-CT]

Originally Posted by pendeloque

I have an 8BA, 1951. When I got it someone had removed the road draft tube and simply put in a pcv valve with a hose leading down below the engine (open). I did not know everything I should have, at the time. I had oil leaks around the gaskets, and oil pushed up thru the oil dip stick tube. That is what led me to understanding blow-by crankcase pressure. I then bought a simple pcv valve from NAPA attached a hose to it and connected it to the vaccuum input beneath the carb (initially for the windshield wipers, now electric). That was a few days ago. So I do not know if I have done the right thing yet. Too soon to tell. However, I have read everything on the internet about pcv oil catch cans and I am looking to install one between the pcv valve and the intake manifold hose input. Must I have a special pcv valve or is the universal one sold at NAPA OK. Is there enough vaccuum to pull thru the oil separator. I really need all the suggestions I can get. Many thanks. Peter

Seeing you have elec. wipers, the old vacuum source works well.
I had the same setup until I went to a 4bbl. carb.
The PCV valve goes into the top road draft tube hole in the intake manifold. (with suitable rubber grommet etc,)
There is adequate vacuum to operate the system.
The PCV valve should be something that was meant to fit an engine close to the same c.i. displacement as our car.
Oil separators, catch cans?? Should not have to use either.

[scooder]

If you have oil pushing out the dip stick tube, a pcv may not have the result you want. Only stuff I've seen that did that were really really worn out, or had no breathers at all, or clogged up breathers.
To clarify, when you got it, it had a hose (where the road draft tube is ment to be) with a pcv valve in it, but this just went to air? Just flopped down the side of the engine? Could you not have just connected this to the old wiper tapping?
As above, the pcv valve should be from a comparable engine. And oil separators, not seen one used on a Flathead, though a bunch of OEM stuff had that setup. Catch cans, these are used when a PCV valve is removed on high performance stuff, the can vents to air via a filter.
Martin.

[Billseye]

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I'm new to the group, but not new to internal combustion. Very interesting and informative post. Only point I would like to add to all of this is that on choosing a pcv valve, most have suggested using one from an equal sized engine. I would think that one should be chosen for its vacuum characteristics. Just my 2 cents...

[scooder]

That don't work unfortunately, though I get your thinking.
A good running stock engine, be it a tiny little import car engine or honking great a dodge hemi will have close to the same vacuum at idle and cruise. This would be around 18-22". But that hemi one will hardly work on the little'un, it would be a big air leak.
So similar sized engines are actually where you should be looking for a doner valve.
Martin.

[luvmyclassics]

What size freeze plug is needed to block off the draft tube on a 52 8BA?

[petehoovie]

PCV4953
1949-53 FORD FLATHEAD PCV VALVE KIT



$39.95




1949-53 FORD FLATHEAD V-8 PCV VALVE KIT REPLACES THE ORIGINAL VENT TUBE WITH A MODERN "PCV" VALVE. IT WILL ELIMINATE BLOW BY SMOKE AND KEEP CONDENSATION OUT OF THE CRANKCASE.
http://jamcosuspension.com/products/...productID/1504

[jrvariel48]

This post died awhile ago, but I'm thinking of installing that exact set up on my motor so I'd like to kick it around again and get some thoughts.
Here's what I have:
1946 59L, which means I have the pan vent.
I have a Camden supercharger on a late intake and right now the road draft tube port is blocked off as is the oil fill port. I'm running an electric fuel pump so I blocked off the mechanical pump and kept the rear road draft tube set up.
From what I'm reading here, if I block off the pan vent and install a PCV set up like the one shown above, it should work fine with a filtered cap on the existing road draft tube. The hose from the PCV valve would be plumbed into the intake under the supercharger. At idle I have 21in. of vacuum and between 15 and 17 cruising light on the throttle.
Am I going in the right direction?
Thanks, Joe

[51 MERC-CT]

The PCV valve should go into the road draft port on the manifold and the filtered cap on the oil filler tube wherever it's located.

[jrvariel48]

Originally Posted by 51 MERC-CT

The PCV valve should go into the road draft port on the manifold and the filtered cap on the oil filler tube wherever it's located.

Yes 51, that's what I'm thinking. I believe the pan vent should be closed also?

[JSeery]

Originally Posted by jrvariel48

Yes 51, that's what I'm thinking. I believe the pan vent should be closed also?

If you use a PCV setup it needs to be a closed system except for a filtered air inlet source. So all unfiltered vents into the crankcase need to be sealed.

[scooder]

Yes the pan vent needs to be blocked. Not sure about the pcv hose going below the blower, these pcv chaps work with vacuum not boost.
I personally would not use a pcv on a supercharged engine. It creates a vacuum leak to the manifold and that vacuum is pulling oil vapour laden air into the engine. This lowers the octane and increases the chance of destination. Just a bad idea in my mind.
Martin.

[jrvariel48]

Originally Posted by JSeery

If you use a PCV setup it needs to be a closed system except for a filtered air inlet source. So all unfiltered vents into the crankcase need to be sealed.

Thanks JSeery

[jrvariel48]

Originally Posted by scooder

Yes the pan vent needs to be blocked. Not sure about the pcv hose going below the blower, these pcv chaps work with vacuum not boost.
I personally would not use a pcv on a supercharged engine. It creates a vacuum leak to the manifold and that vacuum is pulling oil vapour laden air into the engine. This lowers the octane and increases the chance of destination. Just a bad idea in my mind.
Martin.

Scooder, I spoke with someone here on the Barn that runs them on their blown motors with no problems noted. I'm still listening to what you have to say. I found out that I'll be running the PCV to a port that's on the carb. It's a Holley 1850 600cfm. Will this still cause a vacuum leak problem?
I'd love to hear from the blower people if they use a PCV system or not!!
Thank you

[JSeery]

Might try the HAMB as well. I remember some threads a while back on PCV and blower engines.

[jrvariel48]

Originally Posted by JSeery

Might try the HAMB as well. I remember some threads a while back on PCV and blower engines.

Will do!

[scooder]

Originally Posted by jrvariel48

Scooder, I spoke with someone here on the Barn that runs them on their blown motors with no problems noted. I'm still listening to what you have to say. I found out that I'll be running the PCV to a port that's on the carb. It's a Holley 1850 600cfm. Will this still cause a vacuum leak problem?
I'd love to hear from the blower people if they use a PCV system or not!!
Thank you

Yup, still a kind of vacuum leak attached to the carb base. And still obviously oil fume laden air.
Just not something I would do.
Martin.

[51 MERC-CT]

Originally Posted by scooder

Yup, still a kind of vacuum leak attached to the carb base. And still obviously oil fume laden air.
Just not something I would do.
Martin.

Just wonder how millions of vehicles use PCV systems without any vacuum related issues and the "oil fume laden air" gets burnt up in the combustion process as the system was designed to do, also without any issues either real or imagined.

[scooder]

Try plumbing in a air/fuel ratio gauge and see what happens when you add a pcv.
Pcv's are a vacuum leak however you look at them, modern stuff's computer's deal with it fine, it's a bit of a job trying to get a carburettor to deal with it.
Obviously the oily air gets burnt in the combustion process, but it still lowers the resistance to detination (sp?) as does the vacuum leak. This ain't really a concern on a naturally aspirated engine, but bring a supercharger to the party and the needs change. The importance of clean air and good gas goes up massively.
All that being said, with a supercharged engine why make it more prone to detination? A step in the wrong direction I feel.
You can imagine what you want.
Martin.

[51 MERC-CT]

Originally Posted by scooder

Try plumbing in a air/fuel ratio gauge and see what happens when you add a pcv.
Pcv's are a vacuum leak however you look at them, modern stuff's computer's deal with it fine, it's a bit of a job trying to get a carburettor to deal with it.
Obviously the oily air gets burnt in the combustion process, but it still lowers the resistance to detination (sp?) as does the vacuum leak. This ain't really a concern on a naturally aspirated engine, but bring a supercharger to the party and the needs change. The importance of clean air and good gas goes up massively.
All that being said, with a supercharged engine why make it more prone to detination? A step in the wrong direction I feel.
You can imagine what you want.
Martin.

I have had an AF gauge installed for some time and there is not any detectable difference when the PCV vacuum is disconnected. (no imagination or speculation)

[scooder]

That's contrary to what I have found. On a wide band gauge setup and on a workshop exhaust sniffer, the difference was notable, hence my post.
And again, we're talking a supercharged engine here. The fuel mixture is critical so why throw in a variable that ers on the side of lean?
I'd vent to atmosphere, with a catch can. Simple and absolutely won't screw with the fuel curve or effect the rest of the engine in any negative way.
Sure makes sense to me.
Martin.

[Ronnieroadster]

Originally Posted by 51 MERC-CT

Just wonder how millions of vehicles use PCV systems without any vacuum related issues and the "oil fume laden air" gets burnt up in the combustion process as the system was designed to do, also without any issues either real or imagined.

Thats exactly correct and it has no ill effects to any supercharged application also proven by many thousands of miles doing just that with my supercharged vintage Flathead and ARDUN converted engines.
Ronnieroadster

[jrvariel48]

Originally Posted by scooder

Try plumbing in a air/fuel ratio gauge and see what happens when you add a pcv.
Pcv's are a vacuum leak however you look at them, modern stuff's computer's deal with it fine, it's a bit of a job trying to get a carburettor to deal with it.
Obviously the oily air gets burnt in the combustion process, but it still lowers the resistance to detination (sp?) as does the vacuum leak. This ain't really a concern on a naturally aspirated engine, but bring a supercharger to the party and the needs change. The importance of clean air and good gas goes up massively.
All that being said, with a supercharged engine why make it more prone to detination? A step in the wrong direction I feel.
You can imagine what you want.
Martin.

Scooder, I have a wide band air/fuel gauge so I can certainly see if there is a difference if and when I install the pcv. Thanks for your info!

[jrvariel48]

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Scooder- "I'd vent to atmosphere, with a catch can. Simple and absolutely won't screw with the fuel curve or effect the rest of the engine in any negative way.
Sure makes sense to me".
Martin.

Can you elaborate on the catch can set up? Is the pcv still used?
Thanks

[jrvariel48]

Originally Posted by 51 MERC-CT

I have had an AF gauge installed for some time and there is not any detectable difference when the PCV vacuum is disconnected. (no imagination or speculation)

Merc, what set up do you have? Are you running a blower? Tell me what ya got!
Thank you, Joe

[jrvariel48]

Originally Posted by Ronnieroadster

Thats exactly correct and it has no ill effects to any supercharged application also proven by many thousands of miles doing just that with my supercharged vintage Flathead and ARDUN converted engines.
Ronnieroadster

Ronnie, Thanks for your reply! I'm glad to hear about the amount of care free miles you logged with this set up!
Thanks!

[Phil Gillespie]

Originally Posted by 51 MERC-CT

I have had an AF gauge installed for some time and there is not any detectable difference when the PCV vacuum is disconnected. (no imagination or speculation)

Where exactly is the AF gauge sensor installed? As i understand the location of the sensor is important to correct readings.
Phil NZ

[51 MERC-CT]

Originally Posted by Phil Gillespie

Where exactly is the AF gauge sensor installed? As i understand the location of the sensor is important to correct readings.
Phil NZ

Most gauge manufactures provide their recommendation as to where it should be located.
Mine is located about 4 inches behind the left Fenton exhaust flange and in an upper most quadrant of the exhaust pipe.

[jrvariel48]

Mine's a little further down the exhaust as per the manufacturer. I've been reading up on the catch cans and I don't see how it could hurt to have one. It seems like what I'm hearing as compared to what I'm reading about these things, is that it's beneficial especially with a supercharger. It will remove most of the heavy crap from the air going through it. Thoughts??

[jrvariel48]

Can anyone comment any further on a catch can and PCV set up?

[Ronnieroadster]

Originally Posted by jrvariel48

Can anyone comment any further on a catch can and PCV set up?

Dont have a clue as to what a catch can would accomplish. Its certainly no substitute to what a PCV valve is doing.
However A catch can is used when a vacuum pump is added to the crankcase in that capacity the catch can separates the water vapor from the oil. This type of system would only be used in an all out racing application. The one drawback to using a vacuum pump is theres a possibility if the draw is to high oil can be drawn from vital areas such as the piston wrist pins.
Ronnieroadster

[jrvariel48]

Ronnie, I was looking at it in a different way. This would be used in conjunction with the PCV, being mounted in between the PCV and the vacuum source.
Here's what I've read:

Separates oil particles from PCV/CCV air using 50 micron bronze filter
100% billet 6061 aluminum sealed can
Defends intercooler, intake system, and essential components from oil blow-by
Helps maintain proper octane levels to reduce potential detonation

I was looking at it as sort of an air cleaner before it's returned to the motor
Thanks, Joe

[Ronnieroadster]

Originally Posted by jrvariel48

Ronnie, I was looking at it in a different way. This would be used in conjunction with the PCV, being mounted in between the PCV and the vacuum source.
Here's what I've read:

Separates oil particles from PCV/CCV air using 50 micron bronze filter
100% billet 6061 aluminum sealed can
Defends intercooler, intake system, and essential components from oil blow-by
Helps maintain proper octane levels to reduce potential detonation

I was looking at it as sort of an air cleaner before it's returned to the motor
Thanks, Joe

Thats an interesting addition to the PCV system but I see no gain in using it in our vintage engine applications. Heck even the high end performance stuff i have on occasion to be involved with have never used anything like that. However from what you wrote theres no ill effects from using it so if you want to add it to the system go for it just remember it needs to be emptied from time to time if any oil /water ends up in the container.
Ronnieroadster

[jrvariel48]

Originally Posted by Ronnieroadster

Thats an interesting addition to the PCV system but I see no gain in using it in our vintage engine applications. Heck even the high end performance stuff i have on occasion to be involved with have never used anything like that. However from what you wrote theres no ill effects from using it so if you want to add it to the system go for it just remember it needs to be emptied from time to time if any oil /water ends up in the container.
Ronnieroadster

Thanks for the input Ronnie!

[jrvariel48]

Update on the pcv install. I found a dual circuit pcv valve made by Wagner so you can adjust your idle and cruise vacuum requirements separately as well as how much vacuum you're pulling through the pcv. At idle, I'm at 2 inches and cruise about 7 inches. I ran the return back to the carb through a catch can set-up that has a 50 micron bronze filter to help clean up the air a bit and remove moisture or oil before it's reintroduced into the motor. I also installed a K&N breather cap and blocked of the oil pan vent. I just went for a test run and I din't notice any changes as far as air/fuel ratio's.
I did notice that when I'm stopped at a light there's no more smoke!! This is a plus and the main reason I installed this set-up. I know some of you will say it's too expensive and unnecessary, but with the supercharger and detonation being a potential problem, I wanted to be able to adjust the system accordingly. It's a small price to pay compared to a burnt up motor.

[19Fordy]

I don't run a PCV on my 8BA. Tried one and found car ran better without it.

[49Ragtop]

My 63 Cadillac I used to own pulled the crankcase gases right up to the Carburetor using a PCV valve and used a ventilated oil filler cap. I never had any problem with it except you had to keep the PCV valve clean and it was mounted horizontally. I going to do the same with my flathead. only 10 years late than your posts.

[britman]

Originally Posted by DirtyDan

I am running an 8BA w/ an early Eddie Meyer intake. I capped off the road draft tube w/ an elbow fitting and then drilled a hole into the center runners of the intake and installed a threaded PCV valve. It really cut down on the blow by, and it is hidden.

I have a system similar to this set up. After a few thousand miles I have had no problems and I have no blow by inside the car--I don't miss it!

[jrvariel48]

Which PCV valve are you guys using on your set up??

[glennpm]

You need to pick a PCV valve made that is close to your engine displacement. I use one for a 1990 Plymouth Voyager 3.0L or 181cid, V6. The number is PCV333. I went smaller and this works well for me. No oil mist on firewall and didn’t affect my carbs. I have two 97s and 269cid on a 59A.

[jrvariel48]

Originally Posted by glennpm

You need to pick a PCV valve made that is close to your engine displacement. I use one for a 1990 Plymouth Voyager 3.0L or 181cid, V6. The number is PCV333. I went smaller and this works well for me. No oil mist on firewall and didn’t affect my carbs. I have two 97s and 269cid on a 59A.

Great! Thanks, I'll have to do a little searching!

[eicke]

Originally Posted by glennpm

You need to pick a PCV valve made that is close to your engine displacement. I use one for a 1990 Plymouth Voyager 3.0L or 181cid, V6. The number is PCV333. I went smaller and this works well for me. No oil mist on firewall and didn’t affect my carbs. I have two 97s and 269cid on a 59A.

Any pics of this install? Just wonderin' which direction the PCV goes.

[glennpm]

Yes I do! Also look at this post listing a horizontal mounted PCV for a small block Chevy, if you want a larger one than I used:

https://www.jalopyjournal.com/forum/...#post-12322077


Glenn

[eicke]

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Thanks, Glenn! I thought about drilling the manifold in the same spot as yours as mine also has access in tis location.

[glennpm]

Good, glad I could help you!

[markdtn]

Originally Posted by jrvariel48

Which PCV valve are you guys using on your set up??

The vacuum port just below the carb on an iron 8BA intake uses 7/16 banjo threads. I bought a GM disc brake 7/16 banjo bolt and a 7/16 banjo to 3/8 hose barb fitting (AKA 12mm banjo x 10mm barb). I am using a Motorcraft EV68 PCV valve and a Dorman/Help 42052 Grommet in the road draft hole.

[1948F-1Pickup]

My port below the carb (iron factory 8BA intake) is 3/8-18, which is NPT dimension. Just installed a fitting with a 1/16" nipple to run vacuum hose to a "Delco" distributor.
Maybe those manifold ports aren't just one size.....

[blucar]

The vacuum ports on most EFV8 intakes are generally 3/8" to accommodate vacuum for the distributor advance and wipers. The vacuum to operate the Columbia OD is tee'd into this port which is located below the rear carb on my Offie Super manifold.
Generally the engines for the larger trucks have a larger vacuum port to accommodate the vacuum assisted brake booster and/or 2spd rear axle.