Thread: provent oil catch can

I can understand the value of the high pressure valve - should catch can become blocked.

What would be the value of the low pressure valve - i.e. muck sucked back into the crankcase - but under which circumstances might this occur?

Thanks !!

ProVent(R) Style Oil Catch Can Review

It's a one way valve...

Originally Posted by karlz

Cant remember where I read it, but when I considered a catch can someone said something like this "Dont waste your money putting more stuff under the bonnet, just do more frequent oil changes.."

I tend to agree with whoever said that.

I think you might be talking about this thread..

Puma 2.2 Provent 200 kit

I think a provent or catch can that condenses vapour is a good thing for a td5. Typically the vapour mix from the engine will mix with the soot from the EGR and carbon up intakes. This restricts flow of intake air and reduces performance. You could just blank of your EGR but the misconception with EGR is that it reduces performance when in actual fact it's better for your engine.

Right - found this via Asdec FB page:

https://www.mann-hummel.com/fileadmi...nt_en_2013.pdf

Originally Posted by manofaus

I think a provent or catch can that condenses vapour is a good thing for a td5. Typically the vapour mix from the engine will mix with the soot from the EGR and carbon up intakes. This restricts flow of intake air and reduces performance. You could just blank of your EGR but the misconception with EGR is that it reduces performance when in actual fact it's better for your engine.

There seems to be conflicting reports re EGR blanking - obviously the marketing guys would want one to block it - and the greenies otherwise.

For example - a guy like Pete Bell/BAS Tuning - would recommend keeping the CAT and silencers - but his software would disable the EGR in "tuned" mode. I know he has a healthy respect for preserving engine life - so to speak. And removing and servicing the EGR on a 2.2 Puma can be a real job.

Must say after reading all this I am tempted to return to default-/standard mode for a while and observe especially fuel consumption - which may be improved just through lower power output though.

Wonder if if there is an absolute answer - e.g. if there were no emissions legislation - would EGR be part and parcel of the modern engine - say to last longer and/or provide better fuel economy and/or ... not wanting to argue - but also trying to get the facts.

EGR Blanking Info

So we know egr returns unburned gas back into combustion chamber. Part of that gas is unburnt fuel and oxygen. As load demands only certain amounts of fuel for power needed the engine will also burn a portion of the unburnt fuel that has already vapourised and o2 from the egr. Depending on the engine the egr stops functioning at more then 80% throttle on some models. So it reclaims a portion of lost fuel and burns the nox. Its a hotter burn which is good for the cats. Can't say I have seen any dyno results that show half throttle performance difference with egr on or off. Blanking it will reduce soot input into your engine which when combined with vapour from the crankcase builds up on the insides of your intake. The only requirement to have it is because of emissions.

Originally Posted by manofaus

So we know egr returns unburned gas back into combustion chamber. Part of that gas is unburnt fuel and oxygen. As load demands only certain amounts of fuel for power needed the engine will also burn a portion of the unburnt fuel that has already vapourised and o2 from the egr. Depending on the engine the egr stops functioning at more then 80% throttle on some models. So it reclaims a portion of lost fuel and burns the nox. Its a hotter burn which is good for the cats. Can't say I have seen any dyno results that show half throttle performance difference with egr on or off. Blanking it will reduce soot input into your engine which when combined with vapour from the crankcase builds up on the insides of your intake. The only requirement to have it is because of emissions.

I'll comment because some of this is contrary to my understanding of the EGR.

The FSM for the puma refers to the EGR as:
"The EGR system regulates a supply of exhaust gas into the air charge entering the engine, which lowers the combustion
temperature and minimizes the formation of NOX (oxides of nitrogen)."
The EGR cooler is attached to the rear of the exhaust manifold. Coolant from the engine cooling system circulates through
a matrix in the EGR cooler to reduce the temperature of the exhaust gas. Attached to the outlet side of the cooler is the
EGR valve. The valve is motor driven, under the control of the engine control module (ECM), to allow varying amounts of
exhaust gas into the intake manifold depending on the engine operation. At engine switch off the valve opens and closes
several times to clear any deposits which may have accumulated during running.
The EGR outlet tube transports the exhaust gas from the EGR valve to the intake manifold, where it is blended with the
incoming charge air stream by a mixer tube.
The ECM monitors the EGR system function and stores fault codes in the event of failure. The EGR valve can also be
activated for testing using Land Rover approved diagnostic equipment."

So it introduces cooled exhaust gas into the intake charge. This exhaust gas may contain some unburnt fuel and oxygen, but the majority of the exhaust gases will be combustion byproducts (N_2, CO₂, CO, NO_X, Hydrocarbons etc).
The unburnt fuel reclamation purpose is, in my understanding, a fortunate benefit (if at all!), rather than the main aim of the EGR system.
No_X levels are reduced through lower combustion chamber temps, hence the design of the system to 'throttle' or choke the full burn of the fuel charge.

As for the Cats, in petrol engines at least, the CAT operating temp is needed for the best performance of the catalyst, and is achieved through oxygen enrichment, sometimes via introduced air (the mighty nissan 300zx uses an 'air induction valve' system to get the cats up to operating temp quicker).