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While installing my ported intake manifold I wanted to be sure I checked all the valves to see if they were getting gummed up with oil because if they were I was buying a catch can
They all looked pretty clean and there was hardly any oil in the intake manifold either . The "white " you are seeing is the light from my LED flashlight reflecting back
Around 10,000 , this is my new motor that they installed after I dropped the valve . I was really anxious to see if I needed to go out and buy a catch can but after seeing this ... it can wait a few thousand more miles
Inside the old manifold was hardly any trace of oil ....
right, catch cans are only for engines with oil induction issues. Either because the pcv system has failed somehow, or was installed incorrectly, or was engineered poorly, etc..
A healthy motor with proper pcv should never use a catch can. Even if just to keep others from thinking there was something wrong with it... (I Would never run one visibly because I know what they are for and it isn't something I want others to know about) i.e. its a hygiene issue for the engine and the motor is embarrassed about the problem
right, catch cans are only for engines with oil induction issues. Either because the pcv system has failed somehow, or was installed incorrectly, or was engineered poorly, etc..
A healthy motor with proper pcv should never use a catch can. Even if just to keep others from thinking there was something wrong with it... (I Would never run one visibly because I know what they are for and it isn't something I want others to know about) i.e. its a hygiene issue for the engine and the motor is embarrassed about the problem
A properly operating PCV system will still allow ingestion of oil into the intake tract from the crank case. I would argue the exact opposite point and say that all engines should have some kind of Air oil separator to keep these oily vapors from entering the engine. The system I use collects on average 6oz of oil from the PCV line per 5000 miles. I wouldn't want that going back into the engine at all as it would only serve to dilute the quality of the fuel can get stuck to the valves.
That being said these engines due better than some other engines in terms of accumulation of crap on the valves over time. I removed my intake at 33000 miles and had so little gunk on them I didn't bother cleaning them.
A properly operating PCV system will still allow ingestion of oil into the intake tract from the crank case. I would argue the exact opposite point and say that all engines should have some kind of Air oil separator to keep these oily vapors from entering the engine. The system I use collects on average 6oz of oil from the PCV line per 5000 miles. I wouldn't want that going back into the engine at all as it would oil serve to dilute the quality of the fuel can get stuck to the
I agree , i think all motors are going to have some oil vapor blow by , that's the main reason for a PVC system on all engines . I am going to install a catch can because I to want to pull my manifold at 30,000 and see the same thing as I see today. Without the benefit of the gas washing over the valves to clean them I am sure that having a catch can on a DI motor is important
While I'm not running a catch can on my C7, I wouldn't call 10K miles enough use to really evaluate. I have 57K on my car now. There are folks with nearly 200K on these motors and nobody has mentioned needing a decarb procedure like some of the German cars need.
While I'm not running a catch can on my C7, I wouldn't call 10K miles enough use to really evaluate. I have 57K on my car now. There are folks with nearly 200K on these motors and nobody has mentioned needing a decarb procedure like some of the German cars need.
Tool Hoarder ... I get it .. not the reason for my post , the reason is I read all the horror stories and was worried what I would find ...which I was pleasantly surprised , which leads me to believe that I will buy a catch can but I will not be in a rush to get it as my motor is running clean
I wish we would see more pictures like this, a lot of other car forums (for other makes with direct injection) have tons of posts with pictures of their intake valves (and most of them look pretty horrendous, check out a Subaru WRX forum for instance) I'm pretty confident that the LT1 doesn't suffer from any problems with excessive carbon buildup on the backs of the intake valves, but seeing more pictures would still be nice (I'd love to see the intake valves on an LT1 with over 100k and no catch can for instance)
I wish we would see more pictures like this, a lot of other car forums (for other makes with direct injection) have tons of posts with pictures of their intake valves (and most of them look pretty horrendous, check out a Subaru WRX forum for instance) I'm pretty confident that the LT1 doesn't suffer from any problems with excessive carbon buildup on the backs of the intake valves, but seeing more pictures would still be nice (I'd love to see the intake valves on an LT1 with over 100k and no catch can for instance)
When the LT1 came out GM stated it had one of the most extensive oil vapor separators ever mass produced. The valve covers have all those lumps on them for a reason. I have never removed one, but apparently the underside has a very extensive chamber system to remove oil vapor from the crank gasses. I had catch cans on all my C5s. I do not choose to run one on my C7 and have 57K miles on it now with track use 4-5X a year. No issues as of yet.
All LS/T valve covers have had separators built into them. The problem is that is not where most of the oil comes from that gets into the intake. It comes from the PCV.
All LS/T valve covers have had separators built into them. The problem is that is not where most of the oil comes from that gets into the intake. It comes from the PCV.
No LS had separators like the LT has. I owned 4 C5s with one being a full road-race car. I'm familiar with the LS systems. The "PCV" is a system consisting of the valley cover (also with an oil/air separator) and the valve covers. It allows crank vapors to leave the motor and be re-ingested and burnt up while letting fresh air flow in. It's not the valve covers and then "the PCV".
You'd know if the car started to run poorly or was down on power from reduced airflow.
they look cleaner thn mine at 6k with oil separator.
yes with only 6,k miles your set up may be really bad for performance wise after 30,k miles for sure. That stuff starts getting on the valves & your hp will drop for sure... Robert
No LS had separators like the LT has. I owned 4 C5s with one being a full road-race car. I'm familiar with the LS systems. The "PCV" is a system consisting of the valley cover (also with an oil/air separator) and the valve covers. It allows crank vapors to leave the motor and be re-ingested and burnt up while letting fresh air flow in. It's not the valve covers and then "the PCV".
You'd know if the car started to run poorly or was down on power from reduced airflow.
I didn't say they were the same, just that they had baffles in the valve covers and always have. And that most of the oil that gets sucked up into the intake comes from the valley cover/PCV not the valve covers. I have done quite a lot of endurance road racing with LS engines and am very familiar with how much oil they can suck up out of the crackcase and what ports it comes from.
The point is to take care of the problem before the effects are noticed not to wait until there is a problem. Keep it clean now and keep the oil out of the combustion process and the car will run better for longer with fewer issues.
Around 10,000 , this is my new motor that they installed after I dropped the valve . I was really anxious to see if I needed to go out and buy a catch can but after seeing this ... it can wait a few thousand more miles
Inside the old manifold was hardly any trace of oil ....
Dave
It will probably never need one, lots of monkey see monkey do with that product.
03-17-2019, 05:48 PM
Valves are pretty clean
