Breather Tech... Do's and Don'ts... suffocate and die?

I've seen breathers on oil pans on flatheads...
on valley covers..
on valve covers...

I know breathers help the engine breath... obviously...

So when building engines... where should you use them... where shouldn't you?

Anyone have any input on this subject please post it here... as to what advantage/disadvantage breathers have on an engine...

pictures might be a good refrence...
Satanherself posted this rad find earlier today... some rare SP breathers.

I know she was curious why these were so big... they measure 5" across... I guess I'm curious too...

So here I am asking...
what makes for a good breather...
what makes for good placement...
and why?

maybe there are no breather secrets... curious if there is...

Tuck

 

This is always a topic with early hemis.

http://www.jalopyjournal.com/forum/showthread.php?p=1592518#post1592518&highlight=HEMI+Tech

 

Those breathers rule...this will be a good thread. i cant see why it would make a difference but then again running them on the oil pan dosent sound like the best idea...but it looks the coolest.

 

Just discovered a breather on my oil pan...dis-assembling a 1947 Caddy Flatty... didn' know they existed until a week ago.

 

I think the first time I noticed a breather on a flathead was on one of the cheaters cars from milwaulkee...

that link to the hemi breather post is perfect... thanks for posting.

 

Anyone got the same infor for the Nailhead?

 

One thing I see a lot of that I've always heard is a "no-no" is people putting the breathers on the "outside" of the valve covers (the side furthest from the carb) instead of the inside (closest to the carb). This has nothing to do with the carb, I'm only using it as a point of reference.
The reason for this is the outer edges on a V8 are obviously on the downslope while the insides are on an upslope. I was told if you put them on the outer side you would tend to get a ton of oil going into the breathers...

 

But I think you do want to put them as far away from the PCV s possible to get the best cross flow ventilation. I plan to put mine on the front ends of the valve covers, and the pcv will be on the back of the valley pan.

 

PCV valves are a must. Even though they were early "smog" equip. they help the motors out a ton. It is good practice to run a pcv in the valley and a breather in the valve cover to help equal out the presure created in the motor, It is basicly a big air pump. Think about the presure inside your motor at freeway speed turning 4gs, it realy helps alot if you have high compression. Also it helps your gaskets from being pressed out under presure, making oil weap out.

 

I've had two cars with breathers like that with no problems.

 

put a breather on a flathead oil pan to stop it from oiling my firewall...worked better when I dropped a cut off fuel pump rod in ...cam lobe was doing most of the oiling...[ electric fuel pump ].

 

I agree with this statement. Why go through the bother of installing a breather thats not in a stock location when it is actualy easier to install a PCV setup. You would not believe the difference in how clean they become. Check the oil out after 100 miles in a flathead without a PCV and that will make you a believer.

 

I actually use the old add on breathers in my PCV system. This is a mock up. What you can't see is that this breather is blocked off with epoxy above the PCV hose which forces the air to come from it's mate on the other VC and the front oil fill tube. It has worked sucessfully on a few engines. I have no qualms about bolting on a polished breather with no holes. Basically eye candy just like finned valve covers...just decoration. The old brethers definately give the engine an old time look.

Bolting them on the out side creates a trap that retains oil. On the inside they are self draining. Some have had oil fires if the gasket fails and the oil drips onto the manifolds or headers. Personally I think I would spot any weeping before it got to that point.



Look familliar? This is an old digger that was on display at the museum at the Jalopy Showdown. I took this picture just to show off the pan breathers. Pan breathers seems to be a flathead thing. At least I've seen more of them on flat motors than on other varieties.

 

I took Tommy's advice and installed the breathers on my car like he explaned in his tech post. Here are a couple of pics along with the part number for the PCV valve I used.

DD

 

Its really, REALLY, hard to bolt breathers to the valve covers on a flatmotor!

(Thats why they go on the pan)

 

I'm running a breather cap on one side and a PCV on the other:





-Lee
Atomic Radio
www.atomicpinup.com

 

Touche'

 

Great looking motor Lee...................................

 

Took an SOS pad to one,,

 

I have a question:

Was thinking about it and would seem to me one would need to be a trusting soul to Mount the bolt on breathers . I mean what do you do to prevent one of those bolts from coming loose inside and falling into your motor

 

red lock tight

 

Sometimes, no room exists on the "inside" of the valve cover. On an SBC w/ a 6-71, there just isn't any room.

Run a PCV system? I don't think so.

Sure, it helps the eng. to breathe a little more beyond breathers alone.
Do I want to pump a buncha crankcase vapors (oily, nasty & worthless) back into the combustion chambers of an engine I want performance out of?

Uh, no.

Ya want scavaging? Throw that pcv shit in the trash, & let the exhaust system pull it out & burn it instead. You could even make it look pretty trick.

 

It's been my understanding that the breathers were a way to offer additional ventilation to the crankcase in high performance applications before PCV systems became the norm. They helped prevent oil leaks from excess pressure pushing the gaskets out from around valve covers, intakes and oil pans The breathers look cool and function to a point, but on a car that wasn't built for the track and a longevity standpoint, a good PCV system beats them hands down.

That said, there's no reason why you couldn't use those cool vintage breathers you have in conjunction with a PCV valve and get the best of both worlds. Use the breathers as your fresh air intake for the PCV and hide the valve somewhere where it can't be seen. Doesn't matter too much where, but it seems as far away from the breathers as possible would be best. On a strictly race engine, the cleaning/filtering properties of the PCV system may not matter too much as they're usually getting torn down frequently for inspection but on a street car it's must IMO.

Not only does a nice PCV system keep the oil clean it also filters moisture out of the oil. Ever see an old pre/PCV engine with the oil pan rusted through? Exhaust blowby gasses contain water which condenses in the crankcase, sits below the engine oil and rots the pan out from the inside. Engine bearings don't really like water either.

Can you tell I'm a proponent of a well designed PCV system?

 

Like I said. Burn that nasty shit off in the headers. Not in the engine.

 

Here ya go.........

http://www.moroso.com/catalog/categorydisplay.asp?catcode=13023

 

What about an engine with 97's or other carbs without vacuum ports? Is it ok to run a PCV straight to manifold vacuum?

 

Yes you want manifold vacuum. Just don't take it off of an individual cylinder runner where it will lean out the mixture to that cylinder. You want it taken off of the plenum.



This is my PCV valve hook up with dual 97s.

 

Mr. Gasket, Part #6002 also, which I have on the HellRaiser

HellRaiser

 

if you have an inline engine, you can run a breather off the side of the valve cover,then run a baffled pickup at the oil pan, run this pickup to an oil seperator at the back of the block, this lets any oil picked up run back to the pan, the other crap gets sucked up and routed to the pcv valve, i've seen a number of people use traps before the pcv valve to capture all the crap, seems to work well. the point of doing this,is to pull fresh air through the engine, it circulates from the top, down through the engine to the pan,picking up all the blowby and other nastys along the way. this really helps keep gunk out of the oil. if you want to burn it in the exaust just get an old time exaust reed valve, and hook the hose to it instead. the main thing you want is to circulate the air down through the engine to scavenge out as much crap as possible.

 

My 401 has the PVC blocked of. Current carb set-up seen in pic. Where's the best place to plumb mine?