Found a junkyard '77 Maverick 250 air breather , but...

[Mac]

it has too many PCV holes in the side of the body for my 1978 200 ci. My 1978 200ci has two holes in the valve cover and one of those I've run to the port on my Carter YF spacer plate. That leaves my with one opening in my valve cove near the rear in the oil cap, so..... what should I do, plug the remaining 3 holes in the air-breather? You can see 2 of the holes in this pic. Thanks.

 

[Asa]

i'd just plug 'em or try and find something different (although you've put a bit of work into that one, so i doubt you wanna do that)

maybe able to find plugs that would be used to seal holes in the body
i'd put some RTV or something on them when you seal it though

 

[mjpchief]

Why would you need to seal the holes. They are on the outside of the air filter. Air would still be filtered by the air filter before entering the carb. If you use a body plug to seal the holes you could paint them the same color as the air cleaner and they would not be as noticable, but you would not have to use sealer on the plugs.

We used to drill holes in the bottom of the air cleaner housings outside of the filter to allow more air flow back in the '60's & '70's. Don't know if it helped much but it made us feel better about it.

 

[Mac]

Why would you need to seal the holes. They are on the outside of the air filter. Air would still be filtered by the air filter before entering the carb. If you use a body plug to seal the holes you could paint them the same color as the air cleaner and they would not be as noticable, but you would not have to use sealer on the plugs.

We used to drill holes in the bottom of the air cleaner housings outside of the filter to allow more air flow back in the '60's & '70's. Don't know if it helped much but it made us feel better about it.

I was thinking that I needed to plug the holes for venting from the valve cover if I run a hose from there. So long as performance isnt harmed, Im ok with leaving the holes as-is... just wanting to bouce it off you guys cause Im still a rookie.

Also, the metal snout has a vacuum activated throat that I could run a small PCV hose from to a dual outlet PCV, but the original 65 200 air cleaners didnt use it, so just wondering if its worth the effort or would it make any difference? Thanks for the responses.

 

[pedal2themetal45]

OK... The PCV valve what looks to be at the front of the motor goes to the full manifold vacuum at the bace of the carb or the intake.... athe hole in the oil filler cap goes to one of the holes in the air filter housing there should be a little filter at that point in the airfilter housing.. as for the vacuum flap on the air filter snout.... its for a vacuum line that comes from a thrmo tree and has vacuum when cold and it holds that flap open to alow hot air to come from the exhaust manifold for better warm up when its cold... other than that its not needed.... the other hole in the airfilter housing may have been for a emission air pump...
Tim

 

[jamyers]

Like said above, holes in the cleaner housing will hurt nothing except they'll let more air in to the filter. Unless you're going to use the heated-air valve (and I wouldn't), I wouldn't worry.

I would worry about that oil-fill / breather with the hole in it that's not hooked up to anything, iirc there's supposed to be a 90-degree elbow then a short hose going to the cleaner housing, with a small filter on the end. Air is filtered there on its way into the crankcase, then sucked out via the PCV valve and into the intake manifold. I'd get some sort of screen/filter on that crankcase inlet.

 

[Mac]

I would worry about that oil-fill / breather with the hole in it that's not hooked up to anything, iirc there's supposed to be a 90-degree elbow then a short hose going to the cleaner housing, with a small filter on the end. Air is filtered there on its way into the crankcase, then sucked out via the PCV valve and into the intake manifold. I'd get some sort of screen/filter on that crankcase inlet.

Ok, good suggestion. I had intended to buy a filter breather (if thats what you call them) that snaps into the breather housing and hose it to a PCV in that oil filler cap. Glad you confirmed it tho. 8)

 

[JackFish]

I have a hole left over from emissions removal.
I'm not too concerned with appearances so I just put some aluminum tape on the inside of the piece.

 

[shmoozo]

I have a hole left over from emissions removal.
I'm not too concerned with appearances so I just put some aluminum tape on the inside of the piece.

Aluminum tape on the inside to cover the hole, a snazzy decal on the outside to hide the tape and voila! You are good to go!

 

[Mac]

I have a hole left over from emissions removal.
I'm not too concerned with appearances so I just put some aluminum tape on the inside of the piece.

Aluminum tape on the inside to cover the hole, a snazzy decal on the outside to hide the tape and voila! You are good to go!

I like that!!

 

[66 Fastback]

IIRC on the 73 Comet I had, originally they had the PCV line from the valve cover to the air cleaner. Fresh air came via a snorkle. At the air cleaner, the PCV hose connected to a small filter that clipped to the side of the air cleaner. Regardless of whether or not you plug the other holes in air cleaner, you should have a filter on the PCV line if it connects into the air cleaner. The crankcase ventilation line breathes and air flows both in and out. Although the PCV check valve is supposed to only allow one direction of flow, check valves will leak temporarily or eventually. If it is allowed to flow back into the crankcase, you can carry dirty air into the crankcase.

Older cars just vented the crankcase to the atmosphere via road draft tubes. The oxygen that entered the crankcase, degraded the motor oil more rapidly back then, contributing to the formation of acids and sludges. Routing it to the air cleaner basically assumes that the air cleaner is at a lower pressure than the atmospheric pressure. If your air cleaner has extra holes, it will not be operating at as low a pressure when compared to a cleaner that was buttoned up properly.
Doug

 

[Mac]

Older cars just vented the crankcase to the atmosphere via road draft tubes. The oxygen that entered the crankcase, degraded the motor oil more rapidly back then, contributing to the formation of acids and sludges. Routing it to the air cleaner basically assumes that the air cleaner is at a lower pressure than the atmospheric pressure. If your air cleaner has extra holes, it will not be operating at as low a pressure when compared to a cleaner that was buttoned up properly.
Doug

Interesting. Question for everyone. What about the aftermarket air breathers you see sold today? They have a top and bottom that seal around an air filter, which is exposed around its circumference. There is no provision for a valve cover vent, so isnt that bad?

 

[pedal2themetal45]

This is interesting.....
Now the old Road draft tube alowed the crank case to breath naturaly and vent off prusher..
Now adays with the PCV its a different story....
The hose that went from the filler cap to the air filter had a little filter on it in the air cleaner housing as it was more for air being drawn into the crank case but would flow both ways as the carb/motor would ask for air it could draw fumes in from the motor and reburn them. But it wasn't a Positive air flow as the air could go both ways...
Now the oil filler caps with the air filter built into them would alow air flow into the motor so the PCV Valve could draw fresh air into the motor and the PCV valve would draw the fumes right into the intake or the base of the carb to get reburned. This made for a Positive air flow throu the motor (PCV= Positive Crank case ventalation)
Just being hooked to the air filter is acutaly no better that the Road Draft Tube... Well may be a little better as you would have some Positive air flow...
Tim

 

[jamyers]

The aftermarket breathers are ok, they just locate the filter out in the open. Auto manufacturers used a hose to relocate the filter inside the air cleaner housing so it'd be more protected.

An old road-draft tube would make a good bit of suction, a lot more than you'll find inside an aircleaner housing. Just think upside-down chimney. Their main problem was slow speeds and the pollution, plus a LOT of oil used to collect on the roads.

 

[66 Fastback]

Back in the old days, there was more unburned fuel and combustion gases in the crankase. Engine tolerances were looser and everything had carburetors. Tighter tolerances, fuel injection, and engine management computers have cleaned up the crankcase fumes.

But the road draft tube had an advantage compared to newer cars. I had a 1980's vintage company vehicle while drilling some oil wells in Michigan. The engine had so much blowby coming throught the PCV system that it would fog the air filter with oil. The filter plugged up daily from the dusty roads. A road draft tube would not have had that problem. In addition, the oil it would have laid down on the road would have helped keep the dust down.
Doug

 

[Harte3]

Mac:

Most of the filter housings I think you are talking about have a "knockout" inside the filter line for attachment of a breather hose.