Erics Quick71

Hello all I am new to cars/Corvettes.
So bear with me I can use all the help I can.
I have done my first new projects.
Replaced all 4 headlights with working ones.
Added a PCV valve.

NOW I need to add a breather ont he other valve cover.
There was one in the car when I got it(ON the passanger side floor)
Probelm is the post is the same size as my valve cover opening.
Add a grommet-SURELY will not fit....So I need a smaller sized post/breather.

Anyway-
I am looking online at NAPA and they ALL seem to be 1 1/4 inch posts.
Are there possibly more than 1 size.
Maybe 1 1/2 or something larger?
I would like a simple breather...
Maybe like this:

If I can't get one to fit the opening-Is it ok to go with a type like this that clips in?


Just know I would like the valve cover hole filled in before I get to my Dads for help with my first oil change.

OK-2nd question.
I know I need 5 quarts of oil.
BUT what BRAND/WEIGHT do you recommend?
Same for filter.
I am in Northern New Jersey-will that affect the weight of oil?

As far as the actual oil change-My DAD is a car guy(51 Merc right now) So not too worried about the actual oil change now-Just wanna show up with the right stuff.
So its a nice smooth process.
He has all the tools, jacks, ramps, funnels, etc.
May even do it at his friends garage who has a lift so I get to check out the underside in detail.
If I do get the car up-
Does that make it easier to adjust the E-BRAKE?
WOuld definately like that tighter as all the way up-Still roll on level ground...lol

Any help would be appreciated.
I will be picking these items up Today(FRIDAY) after work.

Jack71

Welcome to the forum!!

What is in the breather hole now?

Ideally, you should have a hose going to the air cleaner. A breather will work fine too. You want some kind of filter on that hole. The PCV valve on the other side will suck air out of the motor & that breather valve serves as the filter for air entering the engine crankcase.

As for oil, I always run a synthetic or a blend. 10W 30 should be a good year round oil for you.

Erics Quick71

When I picked it up NOTHING was in either hole.
Engine had just been rebored? and he was just completing assembly when he had to get rid of it. so the story goes...

Anyway-
I did get the PCV to the carb installed.
And since I do not have an original air filter(Dual Snorkel) I cant run the air vent from the valve cover back to the air filter.
SO I need to do a breather.(From what I understand...)

The one that was with the car didnt fit(TOO BIG)-
Guy probably bought the wrong size and was gonna get to it-but had to sell.

I have only driven it a very little without the air breather.
Can I do any damage by doing this with the hole empty in the valve cover? I will be getting it plugged with some type of breather before a 200 mile trip this weekend. So just trying to get some input before I head to NAPA.

Bob Onit

PCV to the carb is fine

I Had the same problem
I searched around auto parts stores until I gound a gromet that would fit inside the valve cover and then I bought a K&N breather that fit inside the gromet.

It looks similar to this one which may fit WITHOUT a gromet




Heres a page where there are quite a few sizes, they may be too small but youll get the idea

http://www.denniskirk.com/jsp/produc...questid=709344

They can be found at local parts stores so you will be able to have it for the weekend
Just measure the inside of the gromet (or the hole in the valve cover) so you know what size breather to buy

Erics Quick71

I just looked at your Vette photos and you have a typical breather valve liek the one I pictured above. I dont see the ype you are talking about on your car?

Bob Onit

You diddnt look close enough, Plus things change daily on my car

Look at the pic named almost_back_to_stock
Should be the first one (top left)
Thats a K&N

Erics Quick71

Your right.
Think the easiest thing is to get the diameter, and go to the store with the car. I can check right then and there-should be an EASY 2 minute installation! Main thing was there ARE different sizes.
I ruined the one he had originally purchased.
I tried to make it tapered so it would fit and cut it all up.
OH WELL.

Bob Onit

I did the same thing
Can you post a pic of your valve cover
Is the aluminum finned type or steel?

GOSFAST

If you use breathers similar to the ones in the photo below you can eliminate the need for a PCV system. They are "washable" and the oil that collects in the filtering material returns it as a liquid directly back inside the unit!

Takes about a 1/2 hour to install each one with simple hand tools. They come with their own templates for drilling hole locations. Thanks, Gary in N.Y.

P.S. These pieces go on almost every "race" unit that leaves here. They are made by "Offenhauser", but are "polished" without the logos.

Bob Onit

Unless they function the same as a PCV valve I would not use it in place of a PCV valve

I did alot of research on PCV and its alot more important than most people think

Erics Quick71

Ok-This is the best I have with me here at work.
This was taken before I did the PCV valve on this side.
BUT is a picture of the valve covers.
I would imagine they are steel.

GOSFAST

Hi Bob, with all the higher end units we do we are totally against any component that "recirculates" contaminants back through intake/carb. Whether it's while idling, high vacuum, or WOT, lower vacuunm. "Oil fumes" just don't help at all in the area of "detonation", actually contributes to it. If you have a unit that has a problem with "blow-by" you'd be better served to correct the issue, not cover it up.

I'll just add one more item here, his covers appear to be cast "finned" aluminum, which would make the "Offy" breathers it little more effort to install. We have done them on those style covers most recently
however and they looked great when finished. Thanks, Gary in N.Y.

P.S. As I stated earlier we send no new units out with a functioning PCV system. Even on the units for the "restored" vehicles that we build for the 100% stock appearing drags (F.A.S.T.) using "low-tension" rings, we have the system's components there for appearance only, none actually function. It's somewhat more of a challenge to make the rings work correctly in these units than in one's where the "stock" looks are not mandated by any "rules"!

Bob Onit

Well It sounds like you build Competition engines so maybe it doesnt apply to you

This all I can tell you at the moment as I dont have access to all my files from work
Maybe it makes a difference , maybe it doesnt



The PCV system uses engine vacuum to pull fumes from inside the engine and burn them when the engine is running. The PCV valve is a check valve that prevents a backfire from igniting the fumes inside the engine. Without a PCV valve, you risk an explosion inside your engine if the fumes inside the engine ignite.

So GOFAST, are you saying that I am better off running a stock L-48 with a breather on each side rather than a PCV Valve?

GOSFAST

Hi again Bob, what I'm stating is this: the only 2 things that should find their way down the carb and into the intake should be fuel and air. Nothing else, not oil OR oil fumes. Of 300+ units per year that we turn out the door, I have not a single one running a "functional" PCV system. As I said above, we do standard resto's for a couple of local shops AND we do the 100% stock appearing units as well.

We've used a number of those Offenhauser breathers through the years and find they really work well. As I said above, they actually
"recirculate" the collected oil/fumes right back inside. That's a design feature of this type breather. Thanks, Gary in N.Y.

P.S. You will not get away with not having some type of "pan-evacuation" system if you have an "existing" internal problem. Remember, years ago nothing had the PCV's at all and there was no appreciable "blow-by", at least on new units, until the point in time where they became "fatigued".

Nemesis_152

i have a hard time believing that the crankcase gasses wouldnt be far beyond the rich limit for an "explosion"


also, how would a backfire, carb or exhaust side, ignite the crankcase gasses?

Mark PittPayne

I've been following this thread for a bit now and have to chime in.

Simply put...Crankcase Breather is a must. ( No Brainer ) Unless you are preparing to turn this into a full time race engine, leave the system alone.

I had a heck of a time finding one myself and settled on the one that BOBONIT has shown. Fits great and breathes great. They are out there, just look around or shop online.

If you start messing with the PCV system...bad things happen...and yes if the engine backfires....kiss it good bye if the PCV system isn't operating as designed.

Go to my website if you want to see how it looks.

Bob Onit

Wekk It sounds like you build Competition engines so maybe it doesnt allly to you

LMAO
I Must have been in a hurry to get out of work..... look at my spelling

Bob Onit

Beats me
I diddnt write it
But I have looked deep into this and the PCV does much more than control what gets released into the environment which is what most people think

BarryK

those are aluminum valve covers

BarryK

ok, you may turn 300+ motors out the door every year but if you don't put on any type of PCV system on them I surely wouldn't buy one from you. Just because you build your motors this way does not mean it's correct. Building something wrong but in large volumes doesn't make it correct because of the number you build.

there are benefits to the PCV system. Yes, it's main purpose is for emissions purposes in which case I'd agree that for a "performance" motor someone could feel they didn't need to add it to their motor, but there ae other purposes and benefits to it also.
he blowby vapors that end up in an engine's crankcase contain moisture as well as combustion byproducts and unburned fuel vapors. The crankcase is sealed to prevent the escape of these gases into the atmosphere, but the vapors must be removed to prevent oil contamination that leads to sludge formation. The PCV system siphons these vapors from the crankcase and routes them into the intake manifold so they can be reburned in the engine.
The PCV valve also acts as a check valve, to prevent flow back into the crankcase. This prevents potential ignition of the crankcase fumes, should the engine backfire. The PCV system is also crucial for to proper engine sealing. The system alleviates crankcase pressure, which can push out on seals and gaskets, contributing to oil leaks.


true, prior to 1963, cars had no PCV and used road draft tubes that just left the hydrocarbon emissions from the crankcase out into the open air.
but just because prior to this time they didn't use a true PCV valve doesn't mean there aren't benefits to the system - that's why they came up with it and started to use it. On Corvettes, the first year they used a real PCV valve was in '66. In '65 the "system" didn't use a true PCV valve, what was used was a 90• fitting with a very samll oriface ( maybe 3/32" ? ) on the side of the carb to use vacuum to draw the crankcase vapors in from the oil fill tube on the front of the intake manifold. The breather portion of the system was a tube at the back of the block running up into the air cleaner housing.
Starting in '66 they added a PCV valve on the oil fill tube and it still ran to the carb for vacuum, just without the 90º fitting used the prior year. this was a more efficent system and didn't have the problem of the 90º fitting getting clogged as would happen on the '65 cars (I know as I have a '65).
The system started with the PCV in '66 ran thru '68 until the SB motors changed to the 350 block which was reconfigured and didn't have the ol fill tube in the front and didn't have the port in the block for the rear breather tube which is when they went to the valve covers for breathing and venting.
There is no problem having the vapors go into the carb or the intake as that's how a properly designed PCV system works - to direct the vapors back into the compustion chambers to be reburnt