Catch Can Vs PCV Revamp

[Rob GTI]

Evening all,

I'm considering one of the above from BSH. The catch can benefits are well recorded with Reds review in the review section and the other long debate started by John O. However I would like to go down the stage 2 route for the following reasons -

Won't forget to empty the can
Won't have to worry about freezing of sludge in winter

Its also cheaper and easier to fit   

BUT.. there is only limited info on the stage 1 fix, to my understanding to diverts the air/oil mix away from the inlet / combustion chamber. Is this right, and if so where does it go?

Also what are there any other pros and cons of these 2?

[bacillus]

Just think of the pcv fix as the catch can set up but without the catch can.   

With the catch can, the vapours that don't condense in the can go into the inlet of the cylinder head and then into the cylinder. At the back of the pcv fix, there is a channel that allows the vapours to go directly to the inlet.

[Rob GTI]

So in other words it does exactly the same as the OEM PCV valve then? Is it a just a case that the valve is more reliable than OEM leading to less contamination of the pipework from leading to the inlet part of cylinder (which apparently can get blocked - like furring of arteries)?

If this is the case then there is just as much potential for carbon deposits to form on valves in the intercooler pipes etc?

[Rob GTI]

Anyone?

[Hurdy]

Yes, there is just as much chance of the carbon deposits with the PCV fix, however it was primarily developed to overcome the OEM PCV's weakness for leaking pressure. The catch can was a further development and designed to go the extra step and catch the vapours that caused the carbon deposits.

[56OctyVRS]

Basically the revamp stops the pressure from venting into the inlet manilfold and causing possible running issues as you get with a broken PCV.  It allows the pressure to be vented from the rear pcv valve which it does anyway when under boost.  A catch can does the same but removes the oily air and only allows clean air back into the cylinder head to be vented via the rear pcv.  I have the catch can and I am still suprised by the amount of fuel vapour, oil that it catches which would have normally been vented into my intake manifold to cake the intake valves up.

[Rob GTI]

Thanks for the replies guys, makes perfect sense, just though the BSH website would have explained it like that  .

Now on the look out for a Catch Can ...............