Oil catch can

M1ck3y · December 13, 2021

I wasn't trying to shame you...

It's impossible to communicate on forums! We should all start doing zoom meetings.

diyer2 · December 13, 2021

I'm a simple man. I don't need to know the chemical make up of what's in my catch can. I like that it isn't going into the engine. Works for me.

Sometimes the ego's and analytical minds cause a thread to get more complicated than necessary IMO.

M1ck3y · December 13, 2021

21 minutes ago, Grumpy Bear said:

All the moisture comes from the crankcase. The can does not CREATE moisture.

But yes, moisture is condensed in the can due to the temperature being LOWER than the condensation temperature of water and light gas cuts.

And now you know why I highlight and bold face. You may not make it to a ripe old age if you don't learn to COMMUNITCATE a thought clearly. You state that the moisture DOES NOT come from the crankcase and is CREATED in the can. (Those are your words in these quotes...right?)

Create can mean 'to cause something to come into existence" such as divorce creates problems for children but the context of your replies states clearly that moisture does not come from the crankcase; indicating the first meaning of creation, to BRING something into existence....(Oxford Languages) i.e. God created heavens and earth Gen 1:1.

Context is the means one uses to decide which of several meanings apply when a word is used.

Slow down....take a deep breath....put the need to dress down an old man down a few degrees of importance...think it through......maybe you will realize how patient I am being. Your welcome.

Condensation forms from humidity in the air. The pcv system is open to the atmosphere, it's pulls air into the crankcase as well as venting excess pressure.

I don't disagree with you stating moisture getting past the rings, along with fuel. But the amount of water created by combustion is minimal, otherwise we'd all have steam cleaned piston tops.

The condensation build up in the can Im refering to, happens when the engine is not in operation.

You can take a look and see a little bit of coffee in the can right after you shut it off. The next morning you'll have some milk with your coffee.

customboss · December 13, 2021

3 reasons not to use the " can " is that

#1 EGR system on all our engines is RECIRCULATING that crap in the engine before the "can" captures it.

#2 masking underlying issues including design issues.

#3 changing crankcase venting pressures out of design spec.

GC mass spec and other MS testing can be done but at my particular OEM we used Thermogravimetric testing and then divided out individual species and used FTIR analyses to fully ID.

In a service I used to offer I called TUNER oil analysis I would test these ( see attached )for $62 and you can tell accurately what your combustion dynamic IS in near real time before analyzers and MIL codes set.

My chiffon is melting reading this thread......meda meda

customboss · December 13, 2021

14 minutes ago, M1ck3y said:

Condensation forms from humidity in the air. The pcv system is open to the atmosphere, it's pulls air into the crankcase as well as venting excess pressure.

Venting to atmosphere on modern engines is 1 way check and while it can vent as long as vent valves are not stuck open, damaged, modified, ingesting atmospheric water vapor will be nil, by design. Modified or race applications etc i.e. not closed vent system then all bets off and I agree with you.

One reason in World of Outlaws and other racing with hygroscopic fuels contamination of engine oils and venting systems we capped headers for transport. Methanol fuels absorb ambient water vapor.

So in the end atmospheric condensation not a player after ~ 2000F+ degrees at combustion chamber...... in modern system.

M1ck3y · December 13, 2021

2 hours ago, customboss said:

Venting to atmosphere on modern engines is 1 way check and while it can vent as long as vent valves are not stuck open, damaged, modified, ingesting atmospheric water vapor will be nil, by design. Modified or race applications etc i.e. not closed vent system then all bets off and I agree with you.

One reason in World of Outlaws and other racing with hygroscopic fuels contamination of engine oils and venting systems we capped headers for transport. Methanol fuels absorb ambient water vapor.

So in the end atmospheric condensation not a player after ~ 2000F+ degrees at combustion chamber...... in modern system.

Not if we're talking GM LT based engines. K2 has a pcv valve in the valley yes. But the valve covers do not have any valve either internally or externally. They are open to the atmosphere via the intake tube.

As I've said, it draws air and vents; constantly looking to maintain equal pressure in the crankcase.

And it's not about the air that it draws. It's about the crankcase be equal to atmospheric pressure. It's not a sealed system. There for air in the system may or may not be high in humidity.

Hence why people see such varying degrees of condensation. From none, to excessive.

*edit*

I'll say it again!

AFTER THE ENGINE IS OFF!

Or am I going to be told the engine has to be running and open to the atmosphere in order to create the appropriate conditions to create condensation.

Edited December 13, 2021 by M1ck3y

customboss · December 13, 2021

POSITIVE crankcase pressure : define?

Pre combustion residence time of ambient humidity ducted in a stock air intake for any GM engine?

% of ambient water vapor post combustion?

Please school me because I want to know the facts.

M1ck3y · December 13, 2021

3 minutes ago, customboss said:

POSITIVE crankcase pressure : define?

Pre combustion residence time of ambient humidity ducted in a stock air intake for any GM engine?

% of ambient water vapor post combustion?

Please school me because I want to know the facts.

Pretty sure I just did. L87 does not have pcv, only the l86.

Find me a parts diagram showing me a pcv valve in the valve covers, or anywhere on the l87 for that matter and I will see if I can find a bowing emoji

TxTruckMan · December 13, 2021

Hasn't about every OEM gone to Direct Injection engines? What percentage of OEM engines actually use a catch can?

customboss · December 13, 2021

8 minutes ago, M1ck3y said:

Pretty sure I just did. L87 does not have pcv, only the l86.

Find me a parts diagram showing me a pcv valve in the valve covers, or anywhere on the l87 for that matter and I will see if I can find a bowing emoji

Just because a modern GM engine doesn't have replaceable valve assembly the spark gasoline engines all have positive crankcase ventilation, right? If they don't they don't meet emissions laws since 1967 ( I think that dates correct).

So how do we get EGR out of the same engines without a traditional EGR valve? Same line of thinking if you follow?

customboss · December 13, 2021

EGR answer : engine valve action, VVT, cam phasing = EGR now. Usually solenoid controlled to meter gases.

M1ck3y · December 13, 2021

18 minutes ago, customboss said:

Just because a modern GM engine doesn't have replaceable valve assembly the spark gasoline engines all have positive crankcase ventilation, right? If they don't they don't meet emissions laws since 1967 ( I think that dates correct).

So how do we get EGR out of the same engines without a traditional EGR valve? Same line of thinking if you

Your ignoring the fact that pre-tb (intake tube) is connected to the valve covers (without valves).

The valve covers house baffles. These baffles by the way are precisely why a catch can isn't warranted on the l87. Well one reason! Many legitment reasons for not needing a can has been posted!

The valve covers are connected to the crankcase via oil return passages.

Now I'm getting confused! There is no egr on these trucks. But there is a fuel vapor system that vents into this system to reintroduce it into the engine.

Edited December 13, 2021 by M1ck3y

customboss · December 13, 2021

OK so how does that change PCV system on every GM gasoline engine since 1967?

I think where we disagree ( best I can tell from your commentary) is that the venting you describe is still not raw air from atmosphere and when you fire the engine the air coming into the combustion chamber will be super dried from that combustion event. If it has some form of cyclonic separation or directional turn or vent deflector no GM engineer will keep his job sucking untreated air into system, from any of the vents you mention.

customboss · December 13, 2021

33 minutes ago, M1ck3y said:

Pretty sure I just did. L87 does not have pcv, only the l86.

Find me a parts diagram showing me a pcv valve in the valve covers, or anywhere on the l87 for that matter and I will see if I can find a bowing emoji

You didn't answer any of those questions but I am sure "your truth" thought you did.