Crankcase ventilation.

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Righty

Righty

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I’ve not had the chance to run my Barracuda for long, but I’m seeing oil build up on the manifold in front of the carburettor, looking in the filter I’m not seeing any signs off oil so at this stage I am thinking dipstick or from the valves on the valve covers.
The previous owner had removed the breather from one cover and instead there are 2 PCV valves neither of which is connected to the vacuum port on the carb, so I’m guessing not a lot of cross ventilation is going on and potentially any build up of vapour etc isn’t able to escape through them.
Even if this isn’t contributing to the leakage I’m thinking I should try to set up a functioning ventilation system. Would anyone have any thoughts on PCV valves to use? The air cleaner housing has a pressed blank for drilling out to insert a fitting to run to the breather, or I could use a breather with a built in filter but I have read they can be problematic if not baffled.

Sorry should addd: 318 with a Holley 4BBL and Street dominator manifold.

IMG_0362.jpeg


IMG_0361.jpeg
 
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Open breather with filter on one side, generic stock replacement pcv on the other, plumbed to the carb.

Your oil leak is probably bad valve cover gaskets. Cork sucks, especially if over tightened. Look for rubber gaskets with metal in them.
 
remytherat said:
Open breather with filter on one side, generic stock replacement pcv on the other, plumbed to the carb.

Your oil leak is probably bad valve cover gaskets. Cork sucks, especially if over tightened. Look for silicone gaskets with metal in them.
Click to expand...
Thanks, I imagine they are pretty old so it would be sensible to replace them any way.
 
Open breather on one side is incorrect. The valve cover breather for the PCV system should be a closed type with a hose nipple that gets a hose routed from the breather to the bottom of the air cleaner. Then you will have a complete PCV system, instead of gettin that "buildup" all over your valve cover from an incorrect open breather. You need a complete PCV system, not incomplete.

Something like this for the under side of your air cleaner:

Breather Fitting

Something like this for your valve cover:

Breather
 
RustyRatRod said:
Open breather on one side is incorrect. The valve cover breather for the PCV system should be a closed type with a hose nipple that gets a hose routed from the breather to the bottom of the air cleaner. Then you will have a complete PCV system, instead of gettin that "buildup" all over your valve cover from an incorrect open breather. You need a complete PCV system, not incomplete.

Something like this for the under side of your air cleaner:

Breather Fitting

Something like this for your valve cover:

Breather
Click to expand...
Thank you, just before I saw you’d posted I found somewhere here selling the adaptor to attach to the air cleaner and ordered the breather with inlet from Year One this afternoon, so yep fully closed.
 
RustyRatRod said:
Open breather on one side is incorrect. The valve cover breather for the PCV system should be a closed type with a hose nipple that gets a hose routed from the breather to the bottom of the air cleaner. Then you will have a complete PCV system, instead of gettin that "buildup" all over your valve cover from an incorrect open breather. You need a complete PCV system, not incomplete.

Something like this for the under side of your air cleaner:

Breather Fitting

Something like this for your valve cover:

Breather
Click to expand...
I have another question not looking for competition performance just common sense opinions, this is a RHD car so the oil filter would foul the steering column in its usual position, so from the factory it came with the filter remote mounted next to the alternator with a rigid pipe set uprunning up and over the engine past the carburettor. So far so good, but this position puts the filter up high and upside down, so I’m wondering is this perhaps not ideal for best function of the filter? A quick fix obviously would be to extend the rigid tubes with a remote mounting kit and locate the filter right way up on the side wall of the engine bay, I wonder if it’s worth it.
 
RustyRatRod said:
…. The valve cover breather for the PCV system should be a closed type with a hose nipple that gets a hose routed from the breather to the bottom of the air cleaner.
Click to expand...

That is the case for the CAP system, but cars had PCV valves before CAP and before the air cleaner attachment for the breather. Not that it makes much difference.
 
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Righty said:
I have another question not looking for competition performance just common sense opinions, this is a RHD car so the oil filter would foul the steering column in its usual position, so from the factory it came with the filter remote mounted next to the alternator with a rigid pipe set uprunning up and over the engine past the carburettor. So far so good, but this position puts the filter up high and upside down, so I’m wondering is this perhaps not ideal for best function of the filter? A quick fix obviously would be to extend the rigid tubes with a remote mounting kit and locate the filter right way up on the side wall of the engine bay, I wonder if it’s worth it.
Click to expand...
running wise the filter doesn't mind how it's mounted. as it is they make an right mess when doing an oil change though.
neil.
 
BSB67 said:
That is the case for the CAP system, but cars had PCV valves before CAP and before the air cleaner attachment for the breather. Not that it makes much difference.
Click to expand...
If you don't want oil residue all over your valve cover, it makes a difference.
 
Righty said:
I have another question not looking for competition performance just common sense opinions, this is a RHD car so the oil filter would foul the steering column in its usual position, so from the factory it came with the filter remote mounted next to the alternator with a rigid pipe set uprunning up and over the engine past the carburettor. So far so good, but this position puts the filter up high and upside down, so I’m wondering is this perhaps not ideal for best function of the filter? A quick fix obviously would be to extend the rigid tubes with a remote mounting kit and locate the filter right way up on the side wall of the engine bay, I wonder if it’s worth it.
Click to expand...
Many millions of slant sixes were made with the oil filter mounted upside down. I don't think it's an issue.
 
Good to know, it’s certainly convenient where it is, although I’m going to need to be careful when I change it as it’s right next to the alternator so I might need to bag that up.
 
Righty said:
Good to know, it’s certainly convenient where it is, although I’m going to need to be careful when I change it as it’s right next to the alternator so I might need to bag that up.
Click to expand...
I've seen some slant sixes from other countries that had the old canister style filter. If you could find something like that, there's another option.
 
RustyRatRod said:
If you don't want oil residue all over your valve cover, it makes a difference.
Click to expand...
I have three sixties Mopars with an open breather/oil cap on one side, pcv on the other. Never had oil residue on my valve covers. Except when my high mileage 340 had five broken rings. :eek:

My 65 273 in 1969:

1743125159809.jpeg

Air gets sucked into the breather, blows out through the pcv.

Before the pcv, there was the road draft tube, which just expelled the vapors under the chassis. Worked best when the car was moving.

1743126405898.jpeg
 
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remytherat said:
Open breather with filter on one side, generic stock replacement pcv on the other, plumbed to the carb.

Your oil leak is probably bad valve cover gaskets. Cork sucks, especially if over tightened. Look for rubber gaskets with metal in them.
Click to expand...
they make those for mopar ....used them on sb chevys ...felpro...oil pans too ?
 
Righty said:
I had heard that’s why you need a baffle fitted inside the valve cover with an open breather to help stop blowback.
Click to expand...
baffle is so you don't suck raw splashing oil only vapor ,and oil don't splash out the breather
 
that build up on your manifold is probably oil wicking up thru the manifold bolts or a bad valve cover gasket.

anything else would oil down half the engine bay to get that much collected in one area.
 
One reason PCVs get disconnected is because a bigger cam is installed in the engine, & these have less vacuum at idle. Not enough vac to pull in the pintle inside the PCV.....
So the PCV gets disconnected....
 
65 Cuda 340 said:
I have three sixties Mopars with an open breather/oil cap on one side, pcv on the other. Never had oil residue on my valve covers. Except when my high mileage 340 had five broken rings. :eek:

My 65 273 in 1969:

View attachment 1716384931
Air gets sucked into the breather, blows out through the pcv.

Before the pcv, there was the road draft tube, which just expelled the vapors under the chassis. Worked best when the car was moving.

View attachment 1716384940
Click to expand...
I think in a way i am currently running an unintentional road draft tube, just it's feeding into the engine bay!
 
abodyjoe said:
they look like a stock valve cover. start witht he proper gromets for them..

use a stock pcv valve plumbed to the carb.

Standard Motor Products V165 Standard Motor PCV Valves | Summit Racing

Free Shipping - Standard Motor PCV Valves with qualifying orders of $109. Shop PCV Valves at Summit Racing.
www.summitracing.com

as for the breather there are many ways to go.

View attachment 1716384902

View attachment 1716384903
Click to expand...
Thanks for the link, the grommets do need replacing.
 
Bewy said:
One reason PCVs get disconnected is because a bigger cam is installed in the engine, & these have less vacuum at idle. Not enough vac to pull in the pintle inside the PCV.....
So the PCV gets disconnected....
Click to expand...
Interesting I think the cams may heve been changed I could get a vac gauge and take some readings I assume from the vac port on the carb, but also from the breather side? I think the service manual gives some figures.
 
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