Catch Can Thoughts

[TheRoyalStig]

Hello all!

Been reading around about catch cans as it's something I've never really bothered with but seeing a lot of folks recommend them for VQ engines.

But also seeing things like this: "there is a wrong assumption that oil catch can will remedy the oil burning issue. While it clears the intake charge of oil ( which prevents carbon deposit in the combustion chamber) , the oil that get in the intake is from crankcase pressure being abnormally high and some of that pressure is sent back to the intake for recycling. An oil catch can simply filters that pressurized air and remove oil vapors, water vapors, etc... , before it is sent back into the intake for recycling. It is then stored inside the can and should be emptied regularly.

The main reason that the crankcase pressure gets high is from blow-by combustion: basically, the burnt mixture makes its way past the piston into the crankcase, this increase the pressure and temperature , vaporizing some oil during that process. There is nothing that can fix that other than replacing the ring/piston.

If you have an engine that have a lot of blow-by, this can help clean the intake charge greatly and you'll temporary gain some power back but since the rings are shot, your engine is on its way out anyway."

So what is everyone's thoughts on them here? Trying to decide if I should do it or not. But if it's more of a bandaid that just technically adds more points of failure(however small) I'd rather not. But I'd like to get some more thoughts!

 

[Racebox]

Hello all!

Been reading around about catch cans as it's something I've never really bothered with but seeing a lot of folks recommend them for VQ engines.

But also seeing things like this: "there is a wrong assumption that oil catch can will remedy the oil burning issue. While it clears the intake charge of oil ( which prevents carbon deposit in the combustion chamber) , the oil that get in the intake is from crankcase pressure being abnormally high and some of that pressure is sent back to the intake for recycling. An oil catch can simply filters that pressurized air and remove oil vapors, water vapors, etc... , before it is sent back into the intake for recycling. It is then stored inside the can and should be emptied regularly.

The main reason that the crankcase pressure gets high is from blow-by combustion: basically, the burnt mixture makes its way past the piston into the crankcase, this increase the pressure and temperature , vaporizing some oil during that process. There is nothing that can fix that other than replacing the ring/piston.

If you have an engine that have a lot of blow-by, this can help clean the intake charge greatly and you'll temporary gain some power back but since the rings are shot, your engine is on its way out anyway."

So what is everyone's thoughts on them here? Trying to decide if I should do it or not. But if it's more of a bandaid that just technically adds more points of failure(however small) I'd rather not. But I'd like to get some more thoughts!

What you said is all correct. We still recommend getting an oil catch can as it keeps the intake clean and helps against carbon build up in the manifold and valves (beneficial since DI doesn’t clean the way PI does). Just make sure to be careful about boost leaks when installing an oil catch can.