Oil Catch Tank

[kev-yorks]

Grizzly there\'s plenty of twins with catch cans as well. Bear with me on this as I\'m not 100% up on the FD engine. I think you only have one engine breather on the filler neck pointing downwards and not the one on the housings that the 20b has but stand corrected if you\'ve both. If its one breather vent then all you need to do is pipe directly from this to the catch tank and blank of the inlet to the PCV that the breather used to vent to, or you could completely remove the PCV assembly and blank the manifold connection or use that connection barb for such as a boost gauge rather than using a tee. If you also have the second breather on the engine itself then you run a second pipe from that also to the catch tank. This is where I\'ve cheated with my setup this second pipe enters at the bottom of the tank and so empties any oil in the tank back to the engine due to gravity when there\'s no positive pressure in the engine. I\'ll try and get some pics of the set up in the morning unless one of the FD guys posts some in the mean time.
Kevin

[Grizzly]

Ahh i\'ve just found another problem with the catch tank Theory, i have just spoke to another mate that has a catch tank fitted, His is conected to what seems to be the vacumm assembly for the Turbo on his Single turbo??? Now i\'m realy getting confuesed.

Off three of my mates that have catch tanks they are all plumbed in Diffrently?

Can some one please let me in on the Definitive Plumbing of a catch tank and its Purpose?

Thanks

[andrewrx7]

Interesting reading about these tanks. This site is a wealth of ideas and info!

Out of interest, if you do fit the tank to the oil filler neck, one of the pipes on the side of the neck (the one that points down) vents into the air inlet pipe, an inch before the primary (front) turbo, so what do you do with this pipe? Clamp it off?

Any idea why this pipe is even there? What is the point of running it through/under the rats nest, down the front of the engine and into the air inlet just before the 1st turbo? Why not just vent if straight into the plenum - only an inch away? Surely a far easier option - so why go to the bother of the complicated routing? Any ideas??

[NixRX7]

Try this link for info on which pipe does what and where to fit your catch tank

http://robrobinette.com/pcv.htm


HTH

Nick

[andrewrx7]

Nice link, thanks!

From what others have described on here, catch tanks can also be plumbed slightly different - taking the pipe from the filler cap to the remote catch tank, which simply vents to air to release pressure. In that case, the pipe, as in "passage 2" in his diagram, or the red pipes in his photo, is open to atmosphere (since it has been pulled off the filler neck to make way for the pipe to the catch tank). If this set up was used, that pipe would need to be clamped off? Would this clamping off cause any issues during the car being on/off boost? That pipe does not have any valves in it, so allows passage of air both ways. I presume that is not that important?

[NixRX7]

the pipe that goes to the inlet manifold you can get rid of, as they did from 95 onwards.
The pipe from the filler neck to the primary turbo is plumbed into the inlet pipe so its always under suction, you could either do as they have and splice a catch tank in, or block this pipe off and have it straight from the filler neck into a catch can then vent to atmos.

Only thing you would need to check is whether you need the suction from that pipe to aid removal of the engine gasses or whether it would be safe to block it off

I think the only reason they have spliced it on that site is because of the strict rules yanks have.

Nick

[dandan]

how remiss of me, i never did post up my own solution, well here it is, in all it\'s, err, glory!


works, too!