• Protip: Profile posts are public! Use Conversations to message other members privately. Everyone can see the content of a profile post.

Oil catch can

jwmelvin and I are talking about real A/O separators. Not the baffles in our valve covers (1/4" diameter holes) or just a collection of rubber hose.

There is no difference. anything that traps or collects solid/liquid while allowing the passage of gas (air molecules) is an A/O separator.

Lets use a different approach. Imagine the engine is a cup that you fill full of some kind of oil, you can use any cup you want. Think of maybe, a mcdonalds cup I guess, one of those large styrofoam cups. Fill it 1/2 way with oil. Then put a lid on it.

now, Shake the cup vigorously. Does it leak? It depends on how well the lid is, right? And how you shake it, maybe you turn it upside down and so forth. If you can shake the cup and flip it upside down and so forth, and nothing spills out, then the cup is very well sealed, yes? Now, add an air pressure tube to the cup and try again. This additional air pressure (first try 0.05psi, then try 0.1psi, then 1.0psi, then 2.0psi, etc...) simulates blow-by gasses. The additional pressure in the cup will help press oil against the lid, and into other seals, helping it leak oil. Imagine if the cup has a "rear main" or a seal on the bottom as well as the top if you want. Then, shake the cup again and again with this air pressure involved and all these extra seals. Now you are seeing an engine being spun and oil is splashing all over the place inside the cup, trying to get out, with the help of air pressure. If you highly modify the engine to achieve a higher RPM, this would be similar to shaking the cup even harder/faster for example, which might eventually overtake the seals of the cup. Also using a more conform oil (synthetic) will also assist with the oil leaks from the cup, since the molecules tend to be more uniform and smaller, they may fit through the spaces of the seals easier, especially when the seals get old/crusty.

Now, add increased temperature. What does raising temp do to engine oil? It depends on how much temp. The temp rise will further reduce the thickness or resistance of the oil in the cup to flow, and make it even easier to slip past the seals in many cases. All of these things, and engine does to the oil, helps the oil leak from the seals of our cup. Heat, pressure, whipping/shaking, all must be controlled by the cup's lids/seals. If an engine in question has a great set of seals from the factory, then the manufacturer/engineers who designed it have provided you with a great cup with a great set of seals, basically it is that simple. Since the cup needs to "breath" there will always be holes in and out of the cup which must be "separated" from our oil, which we know is trying to work its way out. That is what the baffles are for, that is what the original engineers have tried to do, but often there is some age related wear or other factors (higher rpm or more pressure etc...) that require us to take a second look at the cup's lids/seals. We might need to block a certain port and re-drill/fab a new port in the cup for example. We could also enlarge the cup and make the lid higher or more well shrouded from the oil inside it. You can use your imagination at this point to see other methods for catching oil and returning it to the cup; maybe you install a trap with a pump that catches oil as it leaves the cup and pushes it right back into the cup through an oil storage device (think of a dry sump). Creative measures are called for. The most rudimentary measure is a simple "can" or an external trap to hold the oil as it leaves and waits for us to dump it out later.

So to re-evaluate our situation,
1. we examine our cups ports and seals, as the engine is run (during and after run time) to find weak ports, where seals or baffles are inadequate for the performance we demand.
2. Take measures to catch, or return that leaking oil from the cup wherever it appears.
 
I'm not sure what point you are trying to make. Again, I'm talking about real A/O separators - not generic 1/4" diameter holes drilled in a baffle plate on top of the valve cover. Obviously there is a difference in effectiveness between the two. The reason for adding more effective A/O separator(s) is that our requirements are different than the OEM's.
 
So to re-evaluate our situation,
1. we examine our cups ports and seals, as the engine is run (during and after run time) to find weak ports, where seals or baffles are inadequate for the performance we demand.
2. Take measures to catch, or return that leaking oil from the cup wherever it appears.

I suppose you are not sure what direction to take, are you asking for options to bridge the two ideas? Lets use an example random engine then. The steps would look something like this:

1. Measure the oil output for maximum duration. All engines will eventually leak oil somewhere. The question is, how much, and how often (when)?

Engine A loses 10nL of oil for each 10 days at specific track A which is an 3 hour course of severe 5000-7000rpm usage or drag racing use.
Engine B loses 10uL of oil for each 10 days at specific track A which is an 3 hour course of severe 5000-7000rpm usage or drag racing use.
Engine C loses 5mL of oil for each 10 days at specific track A which is an 3 hour course of severe 5000-7000rpm usage or drag racing use.
Engine D loses 100mL of oil for each 10 days at specific track A which is an 3 hour course of severe 5000-7000rpm usage or drag racing use.
Engine E loses 1L of oil for each 10 days at specific track A which is an 3 hour course of severe 5000-7000rpm usage or drag racing use.
Engine F loses 10L of oil for each 10 days at specific track A which is an 3 hour course of severe 5000-7000rpm usage or drag racing use.


For Engine A, the purpose of nL quantity here is to show that even the impossible, unrealistic solutions are part of the bigger picture and just as important as the real solutions. We take note of engine A, acknowledge its unrealistic existence and understand that it exists merely to draw a continuation for our model's output graph. Engine A is almost too good to be true for our purposes (cheap reliable fast).

For Engine B, the same as engine A, 1uL is not much oil yet. but our graph will be approaching a realistic value soon.

Engine C, this is enough oil to coat a short length of tube and perhaps some of the manifold, and this actually is about our service limit, and can be a target for 180hp/Liter regions in most engines. If we can just use a short piece of plumbing to run our PCV valve then we have provided a maximum PCV action with a smaller differential due to any additional tube or accessories. If an auto-manufacturer hands you an engine like this you wouldn't go adding an additional length of plumbing or 'catch device' unless it was purely for looks (if you think they look cool value).

Engine D is losing enough oil to actually get my attention and show up on the plugs. Now you have to implement a device to catch/stop/return the oil. An additional baffle can be made with a creative duct path that allows oil to be trapped or returned. Many off the shelves devices provide this function and as long as the final goal is met: the end of the tube which feeds the intake is free from significant oil, to keep it off the valves and plugs (and everything else) then that is the final goal completed. How can you control oil without buying something to control it? This is where creativity can play a role, what can you think of, that will route the oil back into the crank case? Can you Create a new hole in the oil pan, similar to an oil drain for a turbocharger, and run a line from that to the location in question that is losing oil? If you choose not to return it, you must catch it. A tube will hold oil along its surface, so you have to look at the total surface of the tube provided and the quantity of the oil as above I have made so all important with the decision making. If the quantity of oil passed between maintenance intervals (in our example we could say that the maint interval was 10days since that is when we are checking to see and measuring) is reasonable to sit on the surface of a given reasonable length of tube then we would not need any additional "can" or bucket to catch the oil, as we have chose not to return it. Another question we have to ask ourselves is, "is this amount of oil normal?" This is where research and experience play a role, if you have owned and/or know other people with the same exact engine you can compare results and that will give you an idea of whether what you are seeing is normal or not. Alternatively, you can pressure test the engine yourself and/or dismantle it and inspect all of it's parts looking for faults where compression and/or oil can leak, and inspect the baffle itself to make sure it looks up to the challenge and inspect for proof that the baffle is may be at fault, possibly re-engineer it or replace it somehow.

Engine E is now obviously having an issue with compression seal. One or more of the compression seals is leaking into the crankcase and pressure is helping the oil pass the baffle in significant amounts. Or the original baffle is poor. The difference between these two situations arises once we note whether the engine is question has models which resemble Engine C at the time you are inspecting an Engine E. In other words, if most of the engines are like Engine C but the one you are inspecting is an Engine E, you now have significant evidence that the compression is leaking past one of the compression seals such as piston rings. If you choose to keep using that engine, then you will implement a device to handle the oil flow as in all other examples. The only other option is to rebuild the engine.

Engine F
is terrible, right? We have to look at the application. If this is a 2.6L engine 1000~rwhp in a pure drag racing 7 or 6 second vehicle competition, then this is considered to some as a normal amount of oil to pass after running down a track a few times. If the engine is a all original truck 5.XL V8 then it has big problems, needs a rebuild as in Engine E. Anything past Engine E which is due to compression seal leakage will generally need a rebuild. Some engines use very high boost pressures and due to engineering constraints (or materials) the crankcase receives a large portion of that pressure, and oil basically comes flying out of their orifices at a high rate. I knew somebody that used to catch it and pour it back in. Ill try to find a picture of the car.
 
Last edited:
Jason, when searching for (2) A/O separators for my N/A setup, I saw the RX design. However, it is(was) $350+ for one, and I needed two. That's why I settled for two of the cheaper Moroso's. No, they're not perfect, but I didn't have time to design my own, and it was the next best alternative in the effectiveness/$ ratio IMO :smile:.

It's a moot point now since they are sitting in the garage collecting dust while I've changed setups. It was just another way for me to gauge how well I built my first engine.

I never had a problem with a gunked TB or oil in the intake manifold when I took apart my N/A engine with ~120k miles on it. Others have seen significant crud around the TB plate (could be due to an improperly-oiled K&N or Unifilter), and even Honcho mentioned he had pooled oil sitting at the bottom of his N/A manifold when he took it apart (N/A stock engine).

I think a proper A/O separator and functioning PCV system is even more essential on a boosted OEM engine. That's due to the increased combustion pressures and (probably) richer tunes that wash the cylinder walls and rings leading to accelerated wear. That's why richer is not always better in FI. People quote their A/F ratios on here for boosted setups and they are much too rich IMO. Oh well, I'm no tuning expert and I guess it is better for the engine to die a slow death than a quick one!

Dave

Kicking this thread back up. Dave, I have a Moroso-style can that I intended to put on the PCV (front head) line before the intake manifold port to remove some of the oil/vapor. The intent was to keep my manifold and TB clean. Reading through Rob Morrison's notes, I'm not sure this will solve the issue of oil burping out of the rear valve cover under WOT and hard cornering at the track. Would connecting the front and rear valve covers via a T-fitting and moving the PCV valve in-line after the T solve the issue? This would equalize both heads and subject both to PCV valve function under intake vacuum. My concern is that at WOT, the PCV would close and the engine would have no way to vent because the air intake hole on the bellows is no longer connected to the engine. I can't figure out how to solve that problem...
 
Kicking this thread back up. Dave, I have a Moroso-style can that I intended to put on the PCV (front head) line before the intake manifold port to remove some of the oil/vapor. The intent was to keep my manifold and TB clean. Reading through Rob Morrison's notes, I'm not sure this will solve the issue of oil burping out of the rear valve cover under WOT and hard cornering at the track. Would connecting the front and rear valve covers via a T-fitting and moving the PCV valve in-line after the T solve the issue? This would equalize both heads and subject both to PCV valve function under intake vacuum. My concern is that at WOT, the PCV would close and the engine would have no way to vent because the air intake hole on the bellows is no longer connected to the engine. I can't figure out how to solve that problem...

On my turbo charged engine I use two Moroso cans: one for each cylinder bank.
For the rear cylinder bank, the catch can is positioned on the right hand side of the engine.
This ensures that any engine oil moving into the (long) hose due to G-forces get zeroed out and gravitates back into the engine in the straights.
Simple but straightforward.
This solved the issue of the catch can filling up with oil after a 15 min track outing!
BTW due to the turbo design, the fumes out of the catch can are vented to air (not proud here) but the principle will also work if you vent them back to the engine of course
 
Last edited:
On my turbo charged engine I use two Moroso cans: one for each cylinder bank.
For the rear cylinder bank, the catch can is positioned on the right hand side of the engine.
This ensures that any engine oil moving into the (long) hose due to G-forces get zeroed out and gravitates back into the engine in the straights.
Simple but straightforward.
This solved the issue of the catch can filling up with oil after a 15 min track outing!
BTW due to the turbo design, the fumes out of the catch can are vented to air (not proud here) but the principle will also work if you vent them back to the engine of course

Thanks for the response! I'm trying to preserve the OEM operation of the system, but with cleaner air circulating. Here is a helpful picture below from Kaz. Under part-throttle operation, the PCV valve is open due to manifold vacuum. The intake manifold sucks out the crankcase gases and vents them into the engine to be burned, creating a vacuum in the crankcase, which draws fresh air from the rear head connection to the throttle bellows. This helps ring seating, power, emissions and keeps your oil cleaner. But, it really soils your throttle body and intake manifold with nasty gunk.

ACtC-3e1kOwCw1eOuTzgD0jXZ7cl85Vb5OXemzDF9Ly94YcN2FUu4-Z154ODdYS2pRdvYOLR-5p_tEGB5T7k2wJ6zHZd1_nEGxDXIyDEuhmFpoxFPiJ2KkgLMSB2y6GkJz8C6S163vq58M83FmsniqqemvFZ=w1080-h608-no


My current solution places a simple catch can on the PCV line so that, under part-throttle operation, it will intercept and separate much of the oil rather than allowing it to enter the intake manifold. This hopefully will help keep my throttle body clean.

ACtC-3dXiVmzH6LE6HnN2AXq5FFRTXasyXSy6t44h61RHT_WfQcwP5_hkN_WMojQFpoemAT3a-bmIYtllPWulmXFDwJOyVoleK_Qah0NrWZPJ1dglOHFyktaPVlsDNsInFxMCHX2miMEmY8wQIrmT_9a3Bix=w1080-h608-no


The problem is what happens at WOT and under hard cornering. According to Rob Morrison at DAL Motorsports, you get the below picture. When you mash the gas and go way into VTEC, the manifold pressure rises to near-atmospheric and the vacuum disappears. This causes the PCV valve to close, rendering the catch can useless. Honda anticipated this, so now the crankcase gases flow OUT of the rear head vent and into the intake tract, again to be burned by the engine. But apparently they made a mistake. With all this positive crankcase pressure in the heads, the rear head fills with oil as it sprays out of the VTEC rocker assemblies and is slow to drain back into the pan. When you yank the steering wheel into a hard right turn, the lateral G's push this oil out of the tube and into the intake bellows.

ACtC-3dpmmtaTDgRdUbZZfLIjOvwUtGykT3ZthiI4o_sbxMEZK3BnV3xCPOdVkTaEe3mym8XLTjFLeOwW6WdF30rze-3SpJ2iW_oxRtd7mVtWtGwXdb0XBbn7HULI88nVcMnIae3nTwhnwhurSW4T-6uNzq4=w1080-h608-no


Your solution works, but the engine is now venting to the outside under positive pressure. Rob's solution at DAL was the same. I'm trying to think of a solution that keeps the circuit closed.
 
Thanks for the response! I'm trying to preserve the OEM operation of the system, but with cleaner air circulating. Here is a helpful picture below from Kaz. Under part-throttle operation, the PCV valve is open due to manifold vacuum. The intake manifold sucks out the crankcase gases and vents them into the engine to be burned, creating a vacuum in the crankcase, which draws fresh air from the rear head connection to the throttle bellows. This helps ring seating, power, emissions and keeps your oil cleaner. But, it really soils your throttle body and intake manifold with nasty gunk.

ACtC-3e1kOwCw1eOuTzgD0jXZ7cl85Vb5OXemzDF9Ly94YcN2FUu4-Z154ODdYS2pRdvYOLR-5p_tEGB5T7k2wJ6zHZd1_nEGxDXIyDEuhmFpoxFPiJ2KkgLMSB2y6GkJz8C6S163vq58M83FmsniqqemvFZ=w1080-h608-no


My current solution places a simple catch can on the PCV line so that, under part-throttle operation, it will intercept and separate much of the oil rather than allowing it to enter the intake manifold. This hopefully will help keep my throttle body clean.

ACtC-3dXiVmzH6LE6HnN2AXq5FFRTXasyXSy6t44h61RHT_WfQcwP5_hkN_WMojQFpoemAT3a-bmIYtllPWulmXFDwJOyVoleK_Qah0NrWZPJ1dglOHFyktaPVlsDNsInFxMCHX2miMEmY8wQIrmT_9a3Bix=w1080-h608-no


The problem is what happens at WOT and under hard cornering. According to Rob Morrison at DAL Motorsports, you get the below picture. When you mash the gas and go way into VTEC, the manifold pressure rises to near-atmospheric and the vacuum disappears. This causes the PCV valve to close, rendering the catch can useless. Honda anticipated this, so now the crankcase gases flow OUT of the rear head vent and into the intake tract, again to be burned by the engine. But apparently they made a mistake. With all this positive crankcase pressure in the heads, the rear head fills with oil as it sprays out of the VTEC rocker assemblies and is slow to drain back into the pan. When you yank the steering wheel into a hard right turn, the lateral G's push this oil out of the tube and into the intake bellows.

ACtC-3dpmmtaTDgRdUbZZfLIjOvwUtGykT3ZthiI4o_sbxMEZK3BnV3xCPOdVkTaEe3mym8XLTjFLeOwW6WdF30rze-3SpJ2iW_oxRtd7mVtWtGwXdb0XBbn7HULI88nVcMnIae3nTwhnwhurSW4T-6uNzq4=w1080-h608-no


Your solution works, but the engine is now venting to the outside under positive pressure. Rob's solution at DAL was the same. I'm trying to think of a solution that keeps the circuit closed.

You've depicted exactly the issue I was facing when cornering hard in right hand corners.
Why not try my solution with the Moroso can on the right hand side for the rear cylinder block but returning the output back to the throttle body as in the OEM setup?
You are back to the close loop system but without the nuisance of the oil in the throttle body.
I'll try to find a picture of my setup.

IMG_2366.JPG

IMG_2367.JPG

IMG_2368.JPG

IMG_2369.JPG
 
Last edited:
CB72 said:
You've depicted exactly the issue I was facing when cornering hard in right hand corners.
Why not try my solution with the Moroso can on the right hand side for the rear cylinder block but returning the output back to the throttle body as in the OEM setup?
You are back to the close loop system but without the nuisance of the oil in the throttle body.
I'll try to find a picture of my setup.

I love your solution! But, the problem is that if I don't vent the can to atmosphere, I'll be plugging the rear head and the crankcase won't vent at all under load. I may just try my initial solution plus maybe a different hose layout for the rear head. If I can angle the hose up exiting the head, perhaps I can block the oil flow out and force it to drain back into the head once the lateral G's stop...
 
I understand your issue but connecting both cam covers with a T-fitting negates any fresh air coming into the cranckase or didn't I understand your proposal?
In fact, I believe it's a moot point if the rear hose fills up with oil during a hard turn in my configuration as first of all there will not be that much oil as the hose folds back to the righ hand side and secondly as soon as you hit the straight the gravity will drain the oil back into the cranckase with the help of the vacuum created from the front cylinder side as soon as you shift gears.
 
I understand your issue but connecting both cam covers with a T-fitting negates any fresh air coming into the cranckase or didn't I understand your proposal?
In fact, I believe it's a moot point if the rear hose fills up with oil during a hard turn in my configuration as first of all there will not be that much oil as the hose folds back to the righ hand side and secondly as soon as you hit the straight the gravity will drain the oil back into the cranckase with the help of the vacuum created from the front cylinder side as soon as you shift gears.

I think I have solved it. I will use your solution to mount the catch high on the right side of the car (perhaps where the fuel injector resistor box used to be). But, I will route the hoses like the NA2. So, the front bank will vent to the intake bellows and the rear bank will have the PCV in-line to the catch can and then to the intake manifold.
 
I think I have solved it. I will use your solution to mount the catch high on the right side of the car (perhaps where the fuel injector resistor box used to be). But, I will route the hoses like the NA2. So, the front bank will vent to the intake bellows and the rear bank will have the PCV in-line to the catch can and then to the intake manifold.

I like to see oil fumes flow like an electric current.
The (variable) voltage source comes from eitheir sides of the throttle body (that acts a variable resistor)
When the throttle is closed there is a high voltage and when it's wide open very little voltage and little current will be drained through the circuit.
The circuit itself comprises a resistor ( the catch can ) and a diode ( the PCV) that let's the current go only one way.
So in your proposal the fresh air comes into the front bank and exits through the rear bank but due to the PCV valve cannot return to the rear bank.
This will stop the return of any oil gathered into the rear bank hose during a hard right hand turn...
To achieve your goals of a closed circuit and draining the oil out of the rear hose after a hard right hand corner why not go back to your initial plan with the fresh air coming into the rear bank and the fumes routed out the front bank through both the PCV valve and the catch can.
So what about the oil pouring into the rear bank hose?
You keep my proposal of a long hose routed first above and to the right hand side of the car to eventually get back to the intake bellows like in the OEM scheme.
Inserting a catch can along the way would be a bonus but maybe not compulsory.
 
I like to see oil fumes flow like an electric current.
The (variable) voltage source comes from eitheir sides of the throttle body (that acts a variable resistor)
When the throttle is closed there is a high voltage and when it's wide open very little voltage and little current will be drained through the circuit.
The circuit itself comprises a resistor ( the catch can ) and a diode ( the PCV) that let's the current go only one way.
So in your proposal the fresh air comes into the front bank and exits through the rear bank but due to the PCV valve cannot return to the rear bank.
This will stop the return of any oil gathered into the rear bank hose during a hard right hand turn...
To achieve your goals of a closed circuit and draining the oil out of the rear hose after a hard right hand corner why not go back to your initial plan with the fresh air coming into the rear bank and the fumes routed out the front bank through both the PCV valve and the catch can.
So what about the oil pouring into the rear bank hose?
You keep my proposal of a long hose routed first above and to the right hand side of the car to eventually get back to the intake bellows like in the OEM scheme.
Inserting a catch can along the way would be a bonus but maybe not compulsory.

This is why I love Prime. There need to be more threads like this! I see what you are saying, but I think the issue is that the crankcase needs to vent, not a particular cylinder bank. Under hard cornering at WOT, the PCV will be closed (little to no vacuum) on the rear head, preventing any flow of oil out of the head. But, the front head will still vent to the bellows, providing crankcase ventilation. So, there never should be any oil in the rear hose. Or am I wrong? I think routing the NA2 way and including the catch can on the PCV line solves all my concerns:

1. Trap crankcase blowby and prevent it from reaching the intake manifold when the PCV is open.
2. Stop oil from exiting the rear head under hard right turns at WOT (PCV closed).
3. Allow crankcase to vent to the intake tract when the PCV is closed.
4. Preserve a closed circuit.
 
This is why I love Prime. There need to be more threads like this! I see what you are saying, but I think the issue is that the crankcase needs to vent, not a particular cylinder bank. Under hard cornering at WOT, the PCV will be closed (little to no vacuum) on the rear head, preventing any flow of oil out of the head. But, the front head will still vent to the bellows, providing crankcase ventilation. So, there never should be any oil in the rear hose. Or am I wrong? I think routing the NA2 way and including the catch can on the PCV line solves all my concerns:

1. Trap crankcase blowby and prevent it from reaching the intake manifold when the PCV is open.
2. Stop oil from exiting the rear head under hard right turns at WOT (PCV closed).
3. Allow crankcase to vent to the intake tract when the PCV is closed.
4. Preserve a closed circuit.

Your reasoning is correct (it's the OEM setup in reverse) but...the PCV valve only acts as a switch as long as there is no positive pressure differential across it.
However when the oil flushes out of the bottom cylinder head towards the PCV valve, there is obviously positive pressure build up and the valve opens letting the oil through.
What's even worse is that the PCV valve will not let the oil flow back when the throttle is closed.
The engine will then just swallow the oil trapped in the hose to the PCV valve...
BTW: I admire the work done on your "Long road to Imola'.
You should publish it in an electronic readable format and sell it through the internet.
 
Your reasoning is correct (it's the OEM setup in reverse) but...the PCV valve only acts as a switch as long as there is no positive pressure differential across it.
However when the oil flushes out of the bottom cylinder head towards the PCV valve, there is obviously positive pressure build up and the valve opens letting the oil through.
What's even worse is that the PCV valve will not let the oil flow back when the throttle is closed.
The engine will then just swallow the oil trapped in the hose to the PCV valve...
BTW: I admire the work done on your "Long road to Imola'.
You should publish it in an electronic readable format and sell it through the internet.

Ah, I see the problem. Even when the PCV is open, it will still prevent oil drain-back in the head. I wonder if moving the PCV further down the line will help? I planned to buy something like this:

https://www.amazon.com/Beck-Arnley-045-0299-PCV-Valve/dp/B000CB0X9K

If I place it up high on the right side of the car close to the catch can, that would give me at least 24 inches of hose to drain oil back down into the head. The long hose could also act as a "reservoir" for oil.

The e-book idea is interesting. I have all the pictures, so it would really come down to finding the time to write it up.
 
Personally, I'd keep it simple.
Keep the OEM scheme with the breathing going from the rear to the front cylinder bank with the PCV valve in it's current position and the catch can as on your drawing.
The income path is like the OEM scheme except that the hose serpentines first to the right before going back to the intake.
Be sure to use a real Moroso type Catch can!
Why not try this scheme and look at the amount of oil in the throttle body after running the car in.
Good luck!
 
Personally, I'd keep it simple.
Keep the OEM scheme with the breathing going from the rear to the front cylinder bank with the PCV valve in it's current position and the catch can as on your drawing.
The income path is like the OEM scheme except that the hose serpentines first to the right before going back to the intake.
Be sure to use a real Moroso type Catch can!
Why not try this scheme and look at the amount of oil in the throttle body after running the car in.
Good luck!

So keep the NA1 layout, but use a long hose (angled up) to exit the rear head and wrap around the engine before connecting to the metal tube that leads to the intake bellows? That's a simpler solution for sure. My main reason for doing this is that I spent ages cleaning my intake manifold and throttle body. I don't want to do it again. :)
 
Yes, I understand you will not want to do it again!
On the other hand a little bit of oil in the throttle body will help lubricate it ...
Keep us informed as if I ever go back to NA that's what I would do.
 
Honcho, your post #132 is the correct depiction of what happens during light-load and heavy-load operation, and is why you need two A/O seperators as I described earlier in this thread.

To fix the rear bank oil issue, the line pickup needs to be modified on your valve cover. For my dry sump, I wanted breathers on both valve covers, but didn't want to deal with any oil puddling in the lines. Basically, it's a Honda design defect and I wanted to fix the problem. This applies to both dry sump setups and conventional systems. So, I plugged the side vent and fitted a 10AN 90 degree bulkhead fitting on the top of both valve covers. It involved drilling into and filing flat the rear cover.

But, it works. No oil in the line in sustained high-g turns on the track with r-compounds. That's one of the reasons why I did the dry-sump many years ago. I also removed it due to maintenance concerns since I really don't drive this car on the track anymore.

Hopefully you can see the fittings in this pic:
View attachment 169192
 
Mac Attack said:
Honcho, your post #132 is the correct depiction of what happens during light-load and heavy-load operation, and is why you need two A/O seperators as I described earlier in this thread.

To fix the rear bank oil issue, the line pickup needs to be modified on your valve cover. For my dry sump, I wanted breathers on both valve covers, but didn't want to deal with any oil puddling in the lines. Basically, it's a Honda design defect and I wanted to fix the problem. This applies to both dry sump setups and conventional systems. So, I plugged the side vent and fitted a 10AN 90 degree bulkhead fitting on the top of both valve covers. It involved drilling into and filing flat the rear cover.

But, it works. No oil in the line in sustained high-g turns on the track with r-compounds. That's one of the reasons why I did the dry-sump many years ago. I also removed it due to maintenance concerns since I really don't drive this car on the track anymore.

Thanks Dave. Is the rear head oil puddling issue a factor of the hose barb placement? In other words, does moving the pickup point to the top of the valve cover prevent oil from entering the return hose? If that's all I need to change, it would really simplify things. I would just run that elbow to the OEM return hard line that leads back to the bellows. I can't imagine the oil could travel straight UP and through the elbow...
 
Elbow fitting

[MENTION=12356]Mac Attack[/MENTION] I'm not using AN fitting, but would something like this work, using rubber washers to seal both sides and cutting the excess thread off? What inside diameter is the hose going to the throttle bellows? It looks like about 1/4".

https://www.usplastic.com/catalog/item.aspx?itemid=33658
 
I don't know the size because mine was all customized with the dry sump, but I wouldn't want that fitting for sure! Why not spend the money on a nice fitting?
 
I don't know the size because mine was all customized with the dry sump, but I wouldn't want that fitting for sure! Why not spend the money on a nice fitting?

Dave, with all the delays on my project, I've decided to stick to my original plan and just use the one catch can on the PCV side and keep the rest OEM. Maybe once the car is back together and driving, I'll take a crack at hacking up some used valve covers and use the "nice" fittings. ;) Good to see you posting here again!
 
Dave, with all the delays on my project, I've decided to stick to my original plan and just use the one catch can on the PCV side and keep the rest OEM. Maybe once the car is back together and driving, I'll take a crack at hacking up some used valve covers and use the "nice" fittings. ;) Good to see you posting here again!

That sounds like a good plan.

I've pretty much unplugged from the internet these days other than investment and camping research. It's been nice!
 
Bumping this. I'm curious if there are any new developments or someone has the "go to" solution for a CTSC car.

I currently have a combo overflow tank + catch can, no PCV, both valve covers tee'd into the catch can, then a filter to the atmosphere. I'm thinking of going to a stock overflow tank, then I would need to solve the catch can situation.

I'd love to just get an off-the-shelf solution if possible. Looks like the only available options at this time are from SoS and S2 carbon works, which are basically the same design. Cedar ridge has one too, but looks like it needs an oil pan mod for draining back into the pan.

I'm leaning toward the SoS cause it's a whole kit. It does include a PCV valve which sounds like it may not make sense in the boosted scenario. Design wise, it's basically the same as I have now: both valve covers route into the can, then vent to the atmosphere. Simple, but maybe not as effective as it could be? Any other options I should be looking at?
 
Back
Top