Chevy Nova Forum banner

1 - 16 of 16 Posts

·
Registered
Joined
·
733 Posts
Discussion Starter #1
Hey again guys,
I made a little fix on the Nova. When I bought it, it had a breather tube coming out of the driver side valve cover. This tube was just going out into open air under the hood. A few people told me that it shouldn't really be like that and I should put a filter on it. Here's a photo (tube is circled in red):


Today, I cut down the tube and slipped a breather filter onto it. Does this look legit? :) I'd like an experts opinion haha
 

·
Moderator
Joined
·
6,458 Posts
I measured the diameter of the hose and drilled that size into the base of my air breather. The hose now sticks up 3/4" into the base. Fumes are now burned off with the combustion and out the tailpipe. Now the air going through the hose is filtered by the car's air filter and if there's too much pressure in the crankcase at higher rpms, the vacuum of the inside of the filter will help relieve any pressure. Clean looking and it works.
 

·
Registered
Joined
·
2,289 Posts
I believe it used to go to the air cleaner and it vented through there. I suspect your way may work but looks odd in my opinion.

Just an opinion and no expert here...
 

·
Registered
Joined
·
733 Posts
Discussion Starter #4
Ya, I'm not sure what it originally went to. The engine was out of a '93 Chevy truck and I'm not sure what kind of set up that originally had. Usually when the Nova would be running with that hose going out into the open air, very small traces of oil (more like a mist) would come out. This oil was getting on my spark plug wire right below it and even on the underside of my hood. Kind of making a mess...

Basically, what I'm wanting to know is if this fix is proper and won't cause any problems....I'm not all that familiar with what's going on inside the engine with gasses and all :rolleyes: There shouldn't be any restriction or anything with this new set up right? Like I said, I don't see a difference between what I had, and what I did with the filter...It's still open like it was, just now filtered. And shorter lol.
 

·
Premium Member
Joined
·
5,544 Posts
Proper... not really.:eek:
Will it work... yes.:rolleyes:
Shane65's method is probably the best way to do it.:cool:
My guess is for what you have now that you'll be replacing the filter as soon as it gets soaked with oil.

But what you have will work.

It's all part of the system to evacuate the crank case and relieve pressure...

Just my:2cents:

Mark
 

·
Registered
Joined
·
2,555 Posts
Does the engine have a PCV valve in it? If it does, and the engine is running well, then all you are doing is pulling clean air INTO the crankcase through there. If it doesn't have a PCV then you would be allowing pressure out of there. And you run the risk of oil vapor all over the engine.
 

·
Registered
Joined
·
733 Posts
Discussion Starter #7
There is no PCV valve. The engine has always run fine with the original set up that I have in the first photo I posted. Like I said, some spurts of oil would come out of the original set up and get into the engine bay. Like ChevyII MD mentioned, all that would happen now is that this filter will get soaked with oil eventually...would it be a good idea to get a PCV valve then attach the filter to that? Isn't a PCV valve basically a check valve?
 

·
Registered
Joined
·
733 Posts
Discussion Starter #9
Looking at the top picture of the hose that is running to the brake booster seems wrong. Brake booster hose normally would come from the rear of the carb or manifold. The front port would go to a PCV on the passenger side valve cover instead of the brake booster.
That hose actually does come from behind the carb. This is an old photo that was sent to me from the previous owner....he must have been in the process of doing some work when he took that photo.
 

·
Registered
Joined
·
733 Posts
Discussion Starter #10
I measured the diameter of the hose and drilled that size into the base of my air breather. The hose now sticks up 3/4" into the base. Fumes are now burned off with the combustion and out the tailpipe. Now the air going through the hose is filtered by the car's air filter and if there's too much pressure in the crankcase at higher rpms, the vacuum of the inside of the filter will help relieve any pressure. Clean looking and it works.
Would you happen to have a photo of this setup? Also, wouldn't drips of oil/vapor get into the air cleaner and go down through the carburetor? Isn't this not a good thing? Or is it such small amounts of oil that it will just burn off?
 

·
Premium Member
Joined
·
5,544 Posts
The oil would more than likely burn off because of such a small amount.
My guess from your original picture with the red circle, that hose,more than likely was plumbed into the original air cleaner along the side and had a fibrous (don't know what else to call it) element that would catch the oil and it was changes periodically during tune ups...

The main reason for the whole set up was to prevent pressure build up in the crank case and the hose to the air cleaner so that the natural pull from the carb would suck the fumes out of the crank case and burn them off during combustion... early emission if you will...

Hope this helps out...

Mark
 

·
Registered
Joined
·
733 Posts
Discussion Starter #12
The oil would more than likely burn off because of such a small amount.
My guess from your original picture with the red circle, that hose,more than likely was plumbed into the original air cleaner along the side and had a fibrous (don't know what else to call it) element that would catch the oil and it was changes periodically during tune ups...

The main reason for the whole set up was to prevent pressure build up in the crank case and the hose to the air cleaner so that the natural pull from the carb would suck the fumes out of the crank case and burn them off during combustion... early emission if you will...

Hope this helps out...

Mark
Makes sense. I've been doing some research online about all this and I'm starting to know the inner workings lol. I'm still an engine novice haha. I know what parts are.....just not necessarily what they do or how they work :eek:

Through some research, I found out that this engine was TBI. I looked up some photos of a stock TBI engine out of early 90's trucks and I see that that hose (in the first photo) did indeed go to the air cleaner assembly. The previous owner changes the carb to a Holley and swung that hose off to the side and let the vapors go out into the atmosphere.
 

·
Registered
Joined
·
733 Posts
Discussion Starter #13
Does the engine have a PCV valve in it? If it does, and the engine is running well, then all you are doing is pulling clean air INTO the crankcase through there. If it doesn't have a PCV then you would be allowing pressure out of there. And you run the risk of oil vapor all over the engine.

Actually, I DO have a PCV valve on the passenger side valve cover after all. I didn't realize it was one.... Here is a photo It's at the bottom of the picture. As you can see, no hose is connected to it. It goes out to the atmosphere.
 

·
Moderator
Joined
·
6,458 Posts
I measured the diameter of the hose and drilled that size into the base of my air breather. The hose now sticks up 3/4" into the base. Fumes are now burned off with the combustion and out the tailpipe. Now the air going through the hose is filtered by the car's air filter and if there's too much pressure in the crankcase at higher rpms, the vacuum of the inside of the filter will help relieve any pressure. Clean looking and it works.
The first picture is the engine from a distance. The second shows the hose sticking up through the air cleaner base(a little sealant around the hose even thought it`s a snug fit).



 

·
Registered
Joined
·
733 Posts
Discussion Starter #16
The first picture is the engine from a distance. The second shows the hose sticking up through the air cleaner base(a little sealant around the hose even thought it`s a snug fit).



Looks good. And that's a PCV valve that the hose it connected to, right? Or the hose just plugged directly into the valve cover?

I can't really see on your passenger side valve cover, but is there a hole to the front of the cover, directly across from the oil cap like I have on mine? If so, what set up do you have going on there?

Also, does it really matter what side a PCV valve is installed on :confused: I've usually seen them on the driver side. I don't see what difference it would make since the gasses are coming from the same area anyway...
 
1 - 16 of 16 Posts
Top