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Standard more cost effective oil catch can solution / top end, baffled, oil catch can?

  • Standard, more cost effective, I want to spend the rest of the money on other things than my 4C

  • Top end, quality is what matters, I only choose the best for my 4C

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Discussion Starter #181 (Edited)
Your OCC oil levels are result of somewhat "normal" driving. Left OCC keeps the crankcase vented while the engine is under light load, or steady throttle. Once the boost steps in, the non return valve closes and right OCC takes over the job until there is boost in the intake manifold. As soon as you step off the gas pedal, the vacuum is generated again in the intake manifold and the left OCC takes the job over again. Street and lightly driven cars will fill up left OCC sooner than right. Track cars will fill up right OCC sooner than left but they are not under boost all the time, so left OCC will fill up too.

Fire extinguisher should be mandatory in every car.
 

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FANTASTIC EXPLANATION Gale!!!! It would be best if everyone that bought this understands this... ;)
 

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Discussion Starter #183
Anyone filled the cups yet?

P.S.: I sprayed my OCC's today with WD40 instead of cleaning them with cloth and degreaser as usual if I get any stains on them and results are decent. Much easier than detailing. Not glossy, not matte, but satin finish. I like it.
 

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Yes... they do work...

110606
 

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Discussion Starter #189 (Edited)
I can lower the T-shaped brackets for few cm's, but then the oil level dip stick will have to be removed before unscrewing the bottom of oil catch can.

Also system works best when it is higher than the valve cover PCV valve.

For spider version I'm designing the brackets at the moment. Spider is tight with engine space compared to coupe. And the squeaking roof is annoying. I'm so glad I have coupe.

And Akrapovic exhaust is droning just as well just at overall a bit lower sound level. Not impressed.
 

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My top doesn't squeak at all. Having said that if you are driving the spider with the top on you are doing it wrong.

My Akra doesn't drone a bit in quiet mode.
My top doesn't squeak either and fits very well and tight. Also, with the top off the sound is absolutely amazing no need to use the radio as the exhaust is pure music. As far a road noise it's actually a little quieter with the top on than the coupe as the engine noise is somewhat isolated.
 

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The top also reduces the cabin noise because it is cloth and absorbs sounds. The coupe on the other hand is like a snare drum inside.
 

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Yes, the Akrapovic on my 2018 looks different than the one pictured. In the US, the Akrapovic exhaust was not an option until the 2017 model year.
 

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So I installed my OCC today. Great quality. Just trying to figure out how to get my engine cover on. I don't want the hoses to touch the manifold cooling shroud as that gets very hot.

@GMS my concern is that the oil catch can sits higher than the PCV valve. How is oil supposed to flow into it? I think its just going to fall back into the valve cover.
 

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Discussion Starter #197 (Edited)
The oil in the OCC is condensed oil vapor which is drawn in to the OCC by vacuum of the engine, oil should never flow in to OCC on its own. OCC ideally should always be higher than PCV. We only want to depressurize the crankcase and keep the air flowing, but leave the oil in the engine, it's not the idea of OCC to keep the oil flowing in.
 

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The oil in the OCC is condensed oil vapor which is drawn in to the OCC by vacuum of the engine, oil should never flow in to OCC on its own. OCC ideally should always be higher than PCV. We only want to depressurize the crankcase and keep the air flowing, but leave the oil in the engine, it's not the idea of OCC to keep the oil flowing in.
So is it a depressurizer or a catch can? I can't understand the need for the cans or how they will fill. Conventional wisdom is always below pcv or valve cover. Oil cant flow upward so it seems to defeat the purpose of the name catch can. It would then be the same as a filter that relieves positive crank pressure. Just trying to understand how this thing is going to fill
 

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Discussion Starter #199
Stock PCV depressurizes the crankcase and at the same time separates oily mist into oil and air, but not entirely and because the modern engine normatives do not allow engines to produce waste (catching oil in the OCC), the oily air takes another circle through the intake into the combustion process. This is where we get to a problem we are addressing with OCC - sludge and carbon build up in the engine internals. With aftermarket mods - OCC, we can now improve the separation of oil and air and prevent oily mist to go through combustion process. We extend the path the oil needs to take, increase the time it has to cool down and condense, and therefore turn in to oil and air. The intake in to the OCC is lower AN fitting and outlet is upper AN fitting, in-between is a filter, even further reducing a chance for an oil to pass through, on top of that OCC's are higher than PCV to even further reduce the chance of oil getting into the intake for a combustion again. It is called an OCC (oil catch can), but you are actually catching misty oil vapors that separate in to oil and air, or more precisely in the OCC bottom tank, you will be catching mixed dirty oil and water.

The time which will take for OCC to fill depends on driving conditions. Left OCC (looking from rear towards front) keeps the crankcase vented while the engine is under light load, or steady throttle (vacuum). Once the boost steps in, the NRV (non return valve) closes and right OCC takes over the job until there is boost in the intake manifold. As soon as you step off the gas pedal, the vacuum is generated again in the intake manifold and the left OCC takes the job over again. Street and lightly driven cars will fill up left OCC sooner than right. Track cars will fill up right OCC sooner than left but they are not under boost all the time, so left OCC will fill up too.

Venting straight in to the air thorough a breather filter is an option if you don't mind greasy engine bay and oily smell behind you. Perhaps better would be to route that in to the exhaust system and let it burn, but not the most elegant solution for a car like 4C, once again smelly.
 

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If there is enough oil to "flow" (as a liquid) to the cans then it would seem to me that you'd have a much bigger problem!
Having the tubes higher than the PCV allow any oil that may "condense" (it's not really a vapour, so the wrong word but similar idea) on the tube wall to eventually drip its way back into the system.
The OCC's are simply there to baffle the oil droplets in the airlfow from getting back into the intake and fouling the back side of the valves, depositing them into the can for convenient elimination without altering the original ventilation design of the engine.
 
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