Catch can

[Xylynx]

I know everyone's got their own opinion on whether they're worth it but I was just wondering if anyone had any feedback on the different designs if catch can that are available. Aside from the eBay special there seems to be two main types, the Mishimoto style, with a bronze filter. And this eBay style which seems to consists of vertical tubes that allow the oil vapour to condense.

 

Does anyone have any information on which of these designs work the best? 

 

Thanks 

[vindaloo]

Expansion plus condesnor surfaces.... I've seen large pop bottles used filled with stainless steel scrubbing pads. The larger the better to allow gas speeds to reduce and condesate to form.

[Gt4thomas]

EBay one looks decent. I think the mishimoto ones are over priced.

 

I have an EBay special can, does the job. I have far less oil in the intake piping now. Also worth using oil resistant tubing, I found that the oil seems to sweat through silicone tubes.

 

Here's mine.

 

[retro]

Just do the elephant hose mod and vent it down by the subframe, I'm doing mine tomorrow.

[JWvrs25]

just dont do it, darkside developments did some testing on catch cans on PD engines and confirmed there was high crank case pressure as a result, as standard setup the turbo sucks the vapours out.

Youve got to remember the tandem pump vents into the crank case so you've got that extra pressure as well. I'd leave it standard or just vent to ground to reduce restriction

[Xylynx]

Thanks for all the feedback as always! 

 

@JWvrs25 yeah I've heard of this being an issue because darkside now sell the MANN ProVent catch can that uses a paper element filter and has a built in pressure relief system.

 

I'm going to have a look into it and do more research but the Mishimoto can has been ruled out because it omits and pressure regulation and the filter looks very restrictive. If I do decide to get one it'll probably be the eBay one that has the numerous tubes to condense the oil as I can't imagine that this will affect the pressure as it seems very free flowing.

 

I'll let everyone know the results.

[JWvrs25]

The issue is that the turbo is what pulls the vapours out the crankcase, no catch can is able to do this hence why the vapours can build up in the crankcase and potentially blow a seal or even cause issues with the oil to the turbo if it cant drain correctly (in extreme cases)

[Xylynx]

@JWvrs25 surely this would only be an issue with a can that vents to atmosphere? Most cans are designed as a sealed system that goes in line with PCV tube and just remove the oil vapour while still allowing the turbo to pull a vacuum through the can. 

[JWvrs25]

Youve got all the pipework to the catchcan, then through the can itself and back through another set of pipework to the intake. Thats a big restriction and plus your still putting those hot gases back into the intake minus a small amount of oil, just as well leave it standard and allow the car to suck in the oil which does no harm if your egr valve is disabled.

[sepulchrave]

On 07/05/2018 at 14:37, JWvrs25 said:

The issue is that the turbo is what pulls the vapours out the crankcase, no catch can is able to do this hence why the vapours can build up in the crankcase and potentially blow a seal or even cause issues with the oil to the turbo if it cant drain correctly (in extreme cases)

 

Positive crankcase ventilation such as you describe is desirable but not essential since the crankcase cannot pressurise if it is adequately ventilated,

PCV is used as a way to fractionally reduce parasitic pumping losses, diesels always pressurise their crankcases due to piston ring blowby from the very high cylinder pressures.

The ideal for ventilation and oil separation would be a large bore tube running to a condensing can connected to the low pressure side of the turbo with a small bore tube and NRV allowing the condensed oil to drain back into the sump when the engine is off.

Edited 9 May, 2018 by sepulchrave