Alfa Romeo 4C Forums banner

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

221 - 240 of 247 Posts

·
Registered
Joined
·
33 Posts
Both cans worked very well, and did their job. As normal with OCC, the fluid is a mix of oil and water condensate. There was probably 25 - 40 ml in the right can and 50 - 75ml in the left.
I know that @GMS asked about the screen or porous media, I say keep the filter we have. No need to swap, as it appears to be doing its job well.
Jealous of your weather and activities! Great photos, thanks.
 

·
Premium Member
Joined
·
1,926 Posts
@NortheastAlfaNut - HAHA, you say that now, BUT we shutdown most of our HPDEs for 3 months in the summer because it is too hot to run for both the driver and cars.
 
  • Like
Reactions: NortheastAlfaNut

·
Registered
Joined
·
976 Posts
Hi Rudy,
With the OCC spider version ready to be released, two questions from an esthetical point of view:
  • where are the spider OCC's located?
  • can they be placed in the coupe as well?
 

·
Vendor
Joined
·
1,119 Posts
Discussion Starter #224
GMS OCC for Spider is in the same location as it is in Coupe, but with different lower and upper bracket, for slightly different position, to make room for lower rear hood.

GMS OCC for Spider can be installed in Coupe as well, but due to lack of space, Spider version is a bit more tight configuration when you have to empty the OCC tanks, but still doable without any major issues. However, the Coupe version of OCC is not compatible with Spider version of OCC.
 

·
Premium Member
Joined
·
1,926 Posts
So now that we have multiple confirmations of how good these are, I have a question about the "viscosity" of fluid in the catch can. Mine was fairly "liquidly", more water viscosity than oily. Is this about what everyone else has?
 
  • Like
Reactions: 4C-ophe

·
Registered
Joined
·
976 Posts
GMS OCC for Spider is in the same location as it is in Coupe, but with different lower and upper bracket, for slightly different position, to make room for lower rear hood.

GMS OCC for Spider can be installed in Coupe as well, but due to lack of space, Spider version is a bit more tight configuration when you have to empty the OCC tanks, but still doable without any major issues. However, the Coupe version of OCC is not compatible with Spider version of OCC.
Any pictures?
 

·
Vendor
Joined
·
1,119 Posts
Discussion Starter #230
I got an interesting question today. Why does 4C require twin OCC setup?

A simple and short explanation to the question would be. Older engines usually run single, simple venting system of crankcase as they are not prone to a carbon build up due to the fuel being injected before the intake valves and consequently cleaning the valves. Newer DFI (direct fuel injection) engines, like 1.75 Tbi is, require more sophisticated crankcase venting to prevent carbon build up as there is no fuel to keep the valves clean as the fuel is injected directly in to the cylinder instead pre-valve. So in 4C double oil catch cans are needed as there are two venting ports. One venting port is in the intake manifold which works when engine is under vacuum (light load, coasting or cruising), but as soon as the boost generates, the NRV (non-return valve) closes this port. Under boost, second port which is before turbo starts to take the function of crankcase venting until the engine goes into vacuum mode again. Combining these two would cause interference of venting ports in between, and the use of additional vacuum NRV on both OCC OUT ports doesn't work correctly either. So double OCC (oil catch can) system is required. The riddle can’t be solved with single OCC, neither with dual IN and single OUT OCC. It could be solved with separated dual IN, dual OUT OCC, but that is basically a double OCC setup.

I hope I explained it reasonably, but if anyone really wants to visualize the issue, it's probably gonna take some drawing as things get quite complicated with all the vacuum flowing within the hoses.
 

·
Registered
Joined
·
36 Posts
With this being such an obvious downside of DFI engines (oil making it back into the engine via the intake) why would auto manufactures not implement a solution to resolve this? Is there some possible downside to having OCC?
 

·
Super Moderator
Joined
·
15,976 Posts
Ah makes sense. Thanks
Probably, on a practical note, another maintenance item (emptying the OCC's) that won't get done. Not so much on an enthusiast car like the 4C, but on "appliance" vehicles which also use DFI.
Cannot see my wife going in there every few months and draining these.
 

·
Premium Member
Joined
·
1,926 Posts
Another track weekend... I have been monitoring the OCC levels and I intentionally didn't empty from last track event in November. For 2 track weekends, the OCC filled about 1/3 of the way on both cans. The fluid could probably be best described as "Flat Coke"... It has that same color and viscosity.... It has worked great and I'm still very happy with the setup.
 

·
Super Moderator
Joined
·
15,976 Posts
Great to hear.

I looked at the setup this weekend, and decided that I’m not going to struggle with the return line to the turbo intake myself. Looks like a pain in the ass, and I’ve been there last year with the exhaust. I think that I’m going to set the system in place and do the easy circuit, then let the dealership do the other when the car goes in for its timing belt service come spring.

I’m a little concerned that the cans are located above the level of the PCV valve, though. It was mentioned earlier in this thread didn’t resonate at the time. But the more that I think about it, the more I don’t really want this “flat Coke”, condensing in the hose and running back in more liquid form toward the valve. This is bothering me somewhat, in terms of long term longevity of the valve. It’s a cheap and easy part to replace, but that’s not the point. It needs to do its job.
Still believe that the OCC is the right thing to do, but what do others think about the elevation differences?
 

·
Registered
2016 Alfa Romeo 4C
Joined
·
821 Posts
I’m a little concerned that the cans are located above the level of the PCV valve, though. It was mentioned earlier in this thread didn’t resonate at the time. But the more that I think about it, the more I don’t really want this “flat Coke”, condensing in the hose and running back in more liquid form toward the valve. This is bothering me somewhat, in terms of long term longevity of the valve. It’s a cheap and easy part to replace, but that’s not the point.
Still believe that the OCC is the right thing to do, but what do others think about the elevation differences?
That was my thinking, so I placed them below the valve level and to the right (spider). I was able to avoid the struggle with the turbo line by connecting to the hard line that goes over the valve cover.
 
221 - 240 of 247 Posts
Top