Dear RS MEET Guy I talked to about Catch Can
 

I didn't have the heart to tell you because you seemed so intent on being right but... Your catchcan is setup very, very wrong.

You have a turbo civic, can't remember what model and I asked you about your catchcan. Remember me? Ok here goes.

What you have done is this... you have taken the line from your chargepipe righ before your throttlebody and run it to your catch can. Then you have taken a 2nd line and run it from the nipple on your valve cover to the other port on the catch can. Anyone see a problem with this?

YOU CAN'T RUN A LINE FROM YOUR CHARGE PIPE TO THE CATCH CAN!!!!

Let me explain what you have done. What does a turbo do? It builds "boost" what is boost? It is positive pressure in the intake system of the motor. What is a Catchcan for? It relieves the motor of unwanted pressure buildup in both the head and and block area. You have made it so your actually injecting boosted air into the top of your valve cover IF your catch can is sealed (it shouldn't be cuz then its not doing anything) OR you have a boost leak through your catch can.

Sorry to be the one to inform you like this but I didn't want to argue with you at the RS meet.

Hope you don't get to offended.

Berz out.

"What is a Catchcan for? It relieves the motor of unwanted pressure buildup in both the head and and block area."

i thought the purpose of a catch can is to catch the oil vapour that goes from the PCV valve to the intake manifold.

I have seen several ways people route an oil catch can.
i am in this camp:
http://www.theoldone.com/sc/type-r/C...an_Diagram.jpg

^ :haha:

I agree but it still shouldn't be coming from the boost side. Should be from the VC -> intake (between the TB and head.)

HAHA Thanks for making this thread better.

When you have a turbo car, some blow by naturally occurs. Pressured air goes past the rings and then you have pressure buildup in the block. Since the head and block are connected with passage ways the pressure then travels to the head. Thats why you see guys with those large added fittings on the the valve cover. It lets the pressure out of the block. and head much better.

Berz out.

The catch can in a force fed application should ALWAYS be atmospherically vented with a check valve.
In an NA application if you are running a catch can it still needs a check valve. In both applications the check valve is most commonly overlooked and without one you can have catastrophic engine failure.
All motors create blow by regardless of turbo or not. How much depends on how well your motor is sealed IE good rings or shit rings.

my valve cover breather is connected to the intake pipe before the turbo but after the filter, that should be fine, right?

　Your turbine will foul with oil as it condenses.

a catch can setup without a check valve could potentially cause 'catastrophic' engine failure.....really?

explain why, im curious to hear this explanation bc my boys dont run check valves in any of their catch can setups, and they are all making big numbers in their cars and they all get shit kicked, and none of them have ever had a engine failure due to not having a check valve in the catch can.

and be careful with your loaded statement "all motors create blowby" That is not entirely true. Some motors depending on what rings are chosen for a specific engine setup COULD have blowby.

It's after hours and I'm into the beer so excuse me if I come off arrogant
All motors create blowby there is never a perfect seal between the cylinder and piston EVEN with gappless rings. The best you can hope for is to MINIMIZE blowby.

So loaded statement, maybe to you yes, but answer me this. Why does EVERY gas burning engine in any automobile get carbon fouled oil?


Because blowby occurs.

"explain why, im curious to hear this explanation bc my boys dont run check valves in any of their catch can setups, and they are all making big numbers in their cars and they all get shit kicked, and none of them have ever had a engine failure due to not having a check valve in the catch can."

You and your boys should go buy a lottery ticket.

Check valves are in place to prevent oxygen from re-entering the crankcase following crankcase explosions. Albeit rare but they do occur.
Again beer here so I dont feel like typing so much to explain the mechanics behind it so use your google before you call me out.

Which cans feature check valves? And what purpose does the breather serve?

I've never seen a can with one I just put one inline with it. Cheap insurance is what it is the correct name is PCV valve.

The best is when guys run a line from both valve covers (if they are separat, like say on an RB20) to the catch can with no breathers and wonder why they need new valve cover gaskets or vavle seals. lol..