Catch Can Oil

[Willfulone]

Hi Everyone,

I get a few emails a week asking if catch cans really work. I did a valve cover job this week and had to remove the catch can to do the work. Here is what came out of the can after 2000 miles of "light" driving.

It was about 2oz.

Peace
Chip

 

[WNH]

Interesting. I wonder how much oil my C6 is blowing into the manifold. :ugh

 

[Willfulone]

Interesting. I wonder how much oil my C6 is blowing into the manifold. :ugh

Our experience tells us that it is most likely about the same...

Peace
Chip

 

[BlackZ51Vett]

Do this oil usually get burned....if not caught in a can?

 

[Willfulone]

Do this oil usually get burned....if not caught in a can?

Yes and stuck to the inside of your manifold and runners...

Peace
Chip

 

[BlackZ51Vett]

:W:W:W:W

 

[AintQik]

LSx motors suck oil. Its a fact of life. I have a catch on mine and every oil change I dump quite a bit out. The more heavily modded the motor the more it will pull simply because its pulling more air and creating more vacuum relative to a stock motor. It does get burned but in extreme cases can cause detonation. Its not a good idea to have oil in the intake at all, but it does happen even from good ole GM. I'm not trying to sell one of his cans, but they do work. Whether or not its worth it to you is another story depending on your application. I stand by the argument that any is too much, but the cars do ok either way.

 

[kelp]

Interesting. I wonder how much oil my C6 is blowing into the manifold. :ugh

Answer: Alot. I have clear catch cans on the two PCV systems of my C6Z. The front one, the small loop between the valley and manifold, collects alot of oil.

My current weekend project is to measure the vacuum on both PCV lines to study the mechanism. I will then be able to decide how to reduce oil collection, while I continue to maintain a high vacuum in the crankcase.

 

[keyplyr]

Having some work done currently and am including an oil catch can. Will adding a catch can significantly alter vacuum pressure? If so, would any adjustments need to be made anywhere?

Next month scheduled for a FAST ported intake install as last step for a complete CAI system. Wanted to start off with a clean manifold.

 

[Willfulone]

Will adding a catch can significantly alter vacuum pressure? If so, would any adjustments need to be made anywhere?
.

Nope...

Peace
Chip

 

[johnm]

I am afraid you will have to educate me. What is a catch can? Where does the oil come from that it catches? where do you install it? how does the oil get in the can. How does an engine that does not have a catch can manage this oil? Where do you go to have one installed? Does this void your warranty? How much does it cost? Does it have an appreciable affect (good or Bad) on performance. Sorry for all the questions but I have never heard of this. thanks

 

[WNH]

I am afraid you will have to educate me. What is a catch can? Where does the oil come from that it catches? where do you install it? how does the oil get in the can. How does an engine that does not have a catch can manage this oil? Where do you go to have one installed? Does this void your warranty? How much does it cost? Does it have an appreciable affect (good or Bad) on performance. Sorry for all the questions but I have never heard of this. thanks

This is what I know about it. Others can add or correct me if I'm wrong.

Look at the engine bay of your C6, from the passenger side, near where the throttle body meets the intake manifold. You should see a small U-shaped hose. It's an 'emission thing', it takes fumes from the crank case and routes the fumes into the intake manifold where it is burnt up.

Now, with the fumes comes some oil, during high revs. The catch can bypasses that hose: The hose enters the catch can, deposits any oil, then passes the fumes into the intake manifold.

I bought a catch can because I saw oil in my intake manifold when I switched it for a ported manifold. The oil was on the inner bottom of the IM and ran down the port holes.

Has no effect on performance and does not effect warrantee.

GM should've included a catch device as standard equipment.

 

[c4c5specialist]

:bash
Why bother?
This is normal occurance in any and all internal combustion engines running at a high rate of engine RPM.
IT can be proven in every single Corvette engine, from pre c4 to present, that if you rev it, positive pressure in the crankcase is produced.
This pushes crankcase vapor out the fresh air tube, into the manifold, where it condenses.
So now if the vapor that would normally be sucked into the engine and BURNED with the PCV system, reverses based on RPM and gets sucked in the engine through the OTHER SIDE of the PCV system, what is abnormal????
Allthebest, c4c5

 

[WNH]

:bash
Why bother?
This is normal occurance in any and all internal combustion engines running at a high rate of engine RPM.
IT can be proven in every single Corvette engine, from pre c4 to present, that if you rev it, positive pressure in the crankcase is produced.
This pushes crankcase vapor out the fresh air tube, into the manifold, where it condenses.
So now if the vapor that would normally be sucked into the engine and BURNED with the PCV system, reverses based on RPM and gets sucked in the engine through the OTHER SIDE of the PCV system, what is abnormal????
Allthebest, c4c5

You are talking about 'vapor' I'm talking about 'oil'.

 

[gmjunkie]

:bash
Why bother?
This is normal occurance in any and all internal combustion engines running at a high rate of engine RPM.
IT can be proven in every single Corvette engine, from pre c4 to present, that if you rev it, positive pressure in the crankcase is produced.
This pushes crankcase vapor out the fresh air tube, into the manifold, where it condenses.
So now if the vapor that would normally be sucked into the engine and BURNED with the PCV system, reverses based on RPM and gets sucked in the engine through the OTHER SIDE of the PCV system, what is abnormal????
Allthebest, c4c5

I have to agree here!!In fact I believe it is doing the Engine a Dis-Service!! In the old days of leaded fuel and No PCV system's, we were Lucky to get 50-60,000 miles out of valves and guides,And Really lucky to get 95-100,000 miles out of a set of rings!!!And then it was a sure bet that there were 2-3 cylinders tapered and you would have to bore it and get a set of pistons too!!Hardly any upper cylinder lubrication except a little lead, If you were a Car Buff,then you may put a few ounces of Marvel Mystery oil in every tank of gas for upper cylinder lubrication religiously and get 100,000 plus out of your valves and guides and maybe 150,000 out of your rings and pistons!!!My Grand Daddy and my Dad were Machinist and Fanatic's about upper cylinder lubrication, and I believe they were 100% Correct!! Heres Why!!I'm Old enough to remember when Cars didn't have a PVC system,just a Breather Cap and a 1 inch tube running from the back of the intake valley to just below the oil pan!! Since PVC systems have been used, engines have been lasting longer!!More Miles with less repairs!! Most all vehicles now days will get at least 100,000 plus out valves and guides some even as much as 200,000-300,000 miles!! My wifes 4.3 Jimmy has over 245,000 and has never had a head off of it, my daughters Z-71 had 196,000 on it and had a head gasket start seeping so we pulled the heads and I was amazed that I could still see the cross hatching in the cylinders!!!We put H/gaskets on it and it's hook'n down the road!! That wouldn't happen in the old days!!!

I'll have a few onces of Upper Cylinder Lubrication per oil change, Thank You!!

 

[c4c5specialist]

You are talking about 'vapor' I'm talking about 'oil'.

You are actually talking about the oil VAPOR that CONDENSES on the colder surfaces inside the intake.
Allthebest, c4c5

 

[TODD L GRIFFITH]

As some of you know, I'm a firm believer in using a catch can with these LSx engines. The amount of oil that gets captured is better off in the can then coating my combustion chambers and intake ports with sludge. Moisture and oil get trapped in the can, not cooked to the inside walls of my heads. Oil in the fuel reduces the overall octane content too, just another reason, especially if you have higher compression. It doesn't stop crankcase ventilation, just the beauty of using the can. Oil vapor still gets to pass through, above the oil level in the can. The only drawback is an additional maintenence issue of draining the can, but is way easy to do, and not such a big deal considering the benefits of a clean fuel burning engine. I discovered this problem a few years ago doing a head swap on my Z. The stock heads were a freakin' mess. I went online searching for a solution and ran across what these NOPI duuuuuuuuudes are doing to deal with the same problem, wella the oil catch can.

 

[TODD L GRIFFITH]

I have to agree here!!In fact I believe it is doing the Engine a Dis-Service!!

I'll have a few onces of Upper Cylinder Lubrication per oil change, Thank You!!

I don't think it affects upper cylinder lubrication to the extent where there isn't any. The can doesn't trap 100% of the oil, small amounts still pass through in addition to oil vapors to keep upper cylinder lubrication. It is the amount of oil the can catches that is the excessive usage problem that has plagued these motors due to a poor PCV design that has been changed so many times on the C5, I frankly lost count.

 

[kelp]

Correction to the myth of positive crankcase pressure: it does not exist. There is always a vacuum present of -1 to -9 mm. I have a meter on this in fact. Also, I have two catch cans installed, which for ME is a lifesaver.

 

[AMpcass]

I have to agree here!!In fact I believe it is doing the Engine a Dis-Service!! In the old days of leaded fuel and -------of Marvel Mystery oil in every tank of gas for upper cylinder lubrication religiously and get 100,000 plus out of your valves and guides and maybe 150,000 out of your rings and pistons!!!My Grand Daddy and my Dad were Machinist and Fanatic's about upper cylinder lubrication, and I believe they were 100% Correct!! --------!!!

I'll have a few onces of Upper Cylinder Lubrication per oil change, Thank You!!

I Agree, We used to use Marvel Mystery oil all the time, (40-50 years ago) in fact I still have some. They even used to make an injector plate that mounted between the Carb and intake manifold. Gave better gas mileage and a lot less upper cylinder wear,