RB20 correct way of oil catch install?

[omp]

Have I hooked this up correctly? I have removed the one way valve/PVC and plugged up the inlet manifold. I have run the 2 hoses into the can and the return back into before the turbo. Is this correct? I will be getting a proper oil/air seperator eventually, so that the cam covers have their own inlets and have one outlet back into the system. Thanks Pete

[Roy]

Other option is to run it back to the PCV valve, that way any fumes/oil that are still present get burnt in the combustion process without passing thru the turbo, piping, BOV and intercooler.

[JasonO]

Other option is to run it back to the PCV valve, that way any fumes/oil that are still present get burnt in the combustion process without passing thru the turbo, piping, BOV and intercooler.

I may be wrong, but.......

Surely if it's plumbed back to the PCV inlet to the plenum, then when the turbo comes on boost, the plenum will be under pressure and so the return line to the catch tank will be pressurised which will feed back to the cam covers, which is bad......

....So you'd think that using the PCV valve in the return to the plenum the cam covers wouldn't be pressurised, however......

....the PCV valve is too strong to be opened by the returning fumes from the catch can, else there'd be no need for a catch can as everything would be sorted by the PCV valve in the first place, and we wouldn't have all this oily mess to clean up

I think it needs to return to the inlet piping, before the turbo so that the negative pressure in front of the turbo acts as a vacum for the outlet from the catch tank.

[JasonO]

Errr I meant to say,

Your plumbing looks right enough, but I'd have kept the PCV line as is

[omp]

Thanks for the replies! ok it seem's like I have done the right thing then.... But keep the opinions coming! Lol!

[Roy]

Surely if it's plumbed back to the PCV inlet to the plenum, then when the turbo comes on boost, the plenum will be under pressure and so the return line to the catch tank will be pressurised which will feed back to the cam covers, which is bad......

??? If you take your PCV valve off and give it a shake, you will hear that it has a ball bearign inside. My understanding is the PCV valve is just a check valve, so when the inlet plnum is on boost the the PCV valve is forced close as the little ball is forced against the valves seat, whereby closing it...so the catch can wont be i pressurised.... so i suppose under boost if you have that much blow by that rocker covers/catch can will be pressurised as the PCV valve is closed under boost making it a closed system under boost, which is why the std setup probably has one return to the PCV valve and another to the inlet pipe...to stop this from happening.

[Zensoku]

omp, the setup you have there, is a 100% legal mod, because what you have done is basically introduced a tank plumbed inline into the standard return lines back into the intake (before the turbo)

You have also removed the PCV valve (another silly thing to say like ATM Machine?!? Positive Crankcase Valve Valve:p) which basically means your engine won't be breathing in crankcase blow-by when you are cruising/idling (off boost) through that valve.

The setup you have now, will simply allow the crankcase vapour to condense and return to oil inside the catch can, and "hopefully" cleaner vapour will be sucked into the turbo inlet...

All those catch cans with the "mini air filter" which acts as the breather (no return line to the inlet) are asking for a police defect.... very illegal mod on a street car...

[Tonkotsu Flavour]

that is correct plumbing.

it may be better to dump the outlet from catch can to the ground somewhere .. but shhh.....it may be kinda illegal but also is blocking the pcv valve as its part of emissions.

or cheaper and cleaner.. run from the 2 rockers, block the pcv then dump to a coke bottle or similar, just hide the bottle deep into the engine bay somewhere...

where can you get that blue tube/piping that you have there???? most hardware stores have the clear plastic piping that goes really soft once there is any heat near it.

[C_DawG]

You have also removed the PCV valve (another silly thing to say like ATM Machine?!? Positive Crankcase Valve Valve:p)

Its Positive Crankcase Ventilation valve. :headspin:

[bbenny]

just another quick question for you omp: where did you get the single outlet fittings that plug into the rocker covers? and do you know their size by any chance!

thanks

Ben.

[omp]

Thanks again for the replies! It is very much appreciated! I am really asking because this engine was rebuilt by a fella and now within 2000km's has poo'ed itself! The crank has 2-3mm end float/play! I was asking in case he TRIED telling me I hooked the oil catch can wrong and has pressurised the sump therefore destroying the bottom end. It does not surprise me as

1/He almost fitted the wrong inlet manifold gasket but spotted this as he had to take the inlet manifold off again to fit the coolant distribution hoses/pipes.

2/Managed to forget to install the dipstick untill I picked it up off the bench and asked who's it was, the engine was in the car.

3/Miss-align the cams by 2 teeth retarded inlet 3 teeth advanced exhaust

4/Sealant through the oil pump and oil pick up therefore lack of oil pressure destroying 3 standard turbo's before it was picked up.

5/Oh yea rang me up asking where the hoses went as he had forgotten.

bbenny I went to the importer and purchased for $5, 2 90deg bends from either a red top RB20DET or RB25DET. I got 1 from each, removed the old twin outlet ones and tapped these into place. Done! Pete

[Guest INASNT]

Or you could have it plummed like mine where u get 0 oil going back into the intake.