Ford Performance Oil Separator

huskeee

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Early signs are that I am getting 7ml per 1000 miles



I think you need to balance these kind of questions to car usage though - easy driving v track time etc ...

As a guide mine is road usage, but I like to play and it isn't used for commuting or motorways much, I also like to let it rev.

If mpg can be used as a metric to judge usage, I'm averaging mid 12’s to mid 14’s (and that's a 'large' UK gallon for anyone stateside reading this), I don't doubt that if I was mostly cruising at low revs and highway miles the can would catch a lot less oil :like:

WD :like:
It's actually the other way around. High manifold vacuum conditions are when you'll collect the most oil through the catch can, and this will occur mostly under part throttle driving. So driving around normally on the street or on cruise is when these are needed the most.

 

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Thanks [email protected] That is a good price. I’ve submitted an Int, shipping quote request. The shipping to AUS varies wildly between vendors and items (even for most economical freight) so it is the total cost (item + int shipping) that matters in the end.
 

huskeee

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Still don’t understand why this is needed. Ford engineers would know if they were needed and they are too cheap to be a money issue. As the Coyote engine has port injection along with the direct injection any oil residue is washed away so not criticising anyone’s decision, I just don’t see it as necessary.
Without knowing the engineers' thoughts, I would say it a couple of reasons. First is that the amount of oil collected varies under driving conditions, as it's related to manifold vacuum. So theoretically you could have a catch can fill up before a service interval, which would not be ideal. As with oil changes, you can't put it on the operator to change it. Hence why it would need to be a drain back system, such as what the Ford engineers developed for the GT500. But now we are heading into costs, and don't underestimate how anal car manufacturers are over costs when it comes to building cars.

Also, port injection will wash the oil off the valve. It won't do anything for the oil building up in the intake manifold.
 

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Without knowing the engineers' thoughts, I would say it a couple of reasons. First is that the amount of oil collected varies under driving conditions, as it's related to manifold vacuum. So theoretically you could have a catch can fill up before a service interval, which would not be ideal. As with oil changes, you can't put it on the operator to change it. Hence why it would need to be a drain back system, such as what the Ford engineers developed for the GT500. But now we are heading into costs, and don't underestimate how anal car manufacturers are over costs when it comes to building cars.

Also, port injection will wash the oil off the valve. It won't do anything for the oil building up in the intake manifold.
Precisely this, great concise explanation.

Just because the OEs don't include them on factory cars, doesn't mean they aren't needed, or that they do "nothing," for those wondering. People can barely be relied on to do oil changes on-time, let alone monitoring the levels of catch cans. Also, as mentioned, the added cost of separator systems like on the GT500.

They absolutely do work, for those doubting it, though this topic always sparks debate.

I'd also add that any excessive oil vapour making it's way into the combustion chamber also affects the fuel, essentially making it a lower effective octane, increasing chances of detonation, because you've now got oil mist and vapour mixed with and messing up the intake air charge; the oil mist itself is also at risk of detonating, prior to the actual fuel at ignition.
 

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Early signs are that I am getting 7ml per 1000 miles



I think you need to balance these kind of questions to car usage though - easy driving v track time etc ...

As a guide mine is road usage, but I like to play and it isn't used for commuting or motorways much, I also like to let it rev.

If mpg can be used as a metric to judge usage, I'm averaging mid 12’s to mid 14’s (and that's a 'large' UK gallon for anyone stateside reading this), I don't doubt that if I was mostly cruising at low revs and highway miles the can would catch a lot less oil :like:

WD :like:
It's actually the other way around. High manifold vacuum conditions are when you'll collect the most oil through the catch can, and this will occur mostly under part throttle driving. So driving around normally on the street or on cruise is when these are needed the most.
OK, I’m going to challenge this - not because I’m being an arse, more for the discussion and my own learning :like:

I accept that the vacuum may be higher under part throttle, but is that not (much) more offset by the increased oil vapour from high crank revs beating the crap out of the oil in the sump and the increased blow by from high rpm and maximum power ?

If not, how come improved breather systems are almost standard on a race cars and they are not more popular on town cars / motorway cruisers ?

I understand about oil surge in race cars and increased blow by on forced induction etc - but for this discussion I’m more interested in the volume of oil vapour / % of oil to air going through the breather when cruising compared to hooning :like:

WD :like:
 


huskeee

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OK, I’m going to challenge this - not because I’m being an arse, more for the discussion and my own learning :like:

I accept that the vacuum may be higher under part throttle, but is that not (much) more offset by the increased oil vapour from high crank revs beating the crap out of the oil in the sump and the increased blow by from high rpm and maximum power ?

If not, how come improved breather systems are almost standard on a race cars and they are not more popular on town cars / motorway cruisers ?

I understand about oil surge in race cars and increased blow by on forced induction etc - but for this discussion I’m more interested in the volume of oil vapour / % of oil to air going through the breather when cruising compared to hooning :like:

WD :like:
It's a good question. So this is where the PCV system is misunderstood, and why I'll probably do a video on it soon. The problem is to fully understand it, you sort of do have to go into it depth. Not that it's overly complicated though.

I will begin with this statement. Oil collected in passenger side separator is related to engine vacuum, not crankcase pressure.

Firstly, the PCV system is there because of emissions. Yes, a vacuum is great at pulling vapors, and having a 'free' scavenge system from the intake manifold vacuum is actually helpful. But without emissions, I think the design would be different. More on that later.

So the vacuum that is created by the intake is actually really strong. Imagine attaching a vacuum cleaner to the valve cover. That is exactly what is happening when the intake is under vacuum. This is why there is a PCV valve, and it's not just an open fitting. The PCV valve has a spring-loaded plunger in it, and it rest shut in two conditions. Firstly, when there is no vacuum ie WOT, it will rest shut. Secondly, when the vacuum is very high, the plunger will also shut. This is to manage the amount of air being sucked into the manifold at very high vacuum.

Now, at WOT, when the PCV valve is shut, there is no vacuum being applied to the valve cover. So any excess crankcase pressure will expel itself under atmospheric pressure. Nothing will suck it out, as is with the case under manifold vacuum. Also, because the PCV valve is shut, any excess vapors will be expelled primarily on the drivers side. As there is no vacuum, this becomes a vent, venting to the intake tube, but only under atmospheric pressure. It is not being sucked out. This is why you will get some oil on the intake tube over time, but usually not much. This is why there are driver's side catch cans, and in most conditions they don't collect anything. Now, if you had an excessive blowby issue, or a modified motor that had loose ring gaps, yes, you will get a lot more vapors coming out under WOT conditions, even to the point where they will push the pcv valve open to vent through there if it was needed.

This brings us on to race motors/built motors/big power forced motors. These will produce more crankcase pressure, due to how they are built, the power they are making, the rev range they are sitting at etc. Now the big thing is they don't have to comply with emissions, so using intake manifold vacuum isn't needed as they don't need to recirculate the vapors. So what you will see is two things. Either vented to atmosphere setups, or vacuum pump setups. Nothing beats a vacuum in terms of the amount of vapor you can pull over a set time, and that is why these pumps are used on big power/dollar setups.

So going back to your questions about vacuum being offset by increased vapors under WOT. Under WOT, on a normal or mild modded street motor, you will get some crank case pressure, but this will have to be expelled under atmospheric pressure. Again, this is why a lot of drivers side cans on mustangs appear to not collect anything. If you have normal crankcase operations and not excessive ring blowby, you will hardly see any oil vented without a vacuum. It will never compete with what the PCV system is doing, and this is pulling vapors under a strong vacuum regardless of what is happening inside the motor. Essentially, the reason you are seeing lots of oil in the passenger side on an OEM pcv system is not because of blowby or crankcase pressure, but because of vacuum. And because of this, the amount of oil on the passenger side will be related to each persons driving conditions, and the amount of time they stay in the intake manifold's vacuum range.
 
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WD Pro

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Thank you, that’s really good info :like:

So going back to my question i.e. oil collected under high rev / high load conditions compared to that for cruising - is Ford incorrect to quote this wording in the instructions ?

1634677305843.png


Surely if cruising collected more oil than hooning, would the instructions not be worded in a way to reflect that ?

WD :like:
 

huskeee

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Yeah look I don't know why they put that there or the reasoning behind it. Maybe it's just a warning to make sure people are checking it.

But actually just thinking about it, under WOT at high RPM you will have a large amount of oil in the heads. When you come off WOT, you will get a strong vacuum, and coupled with the extra oil in the heads, you might be got a lot of oil sucked into the separator that otherwise would not happen if you weren't at a high RPM. So yeah under high RPM driving you might get more oil in the separator, but this would be due to the extra oil and high vacuum, not the excess crankcase pressure. That is just me thinking out loud.
 
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TasGT

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Thanks [email protected] That is a good price. I’ve submitted an Int, shipping quote request. The shipping to AUS varies wildly between vendors and items (even for most economical freight) so it is the total cost (item + int shipping) that matters in the end.
Can you let me know what the quote comes to AJ ?
 
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Early signs are that I am getting 7ml per 1000 miles



I think you need to balance these kind of questions to car usage though - easy driving v track time etc ...

As a guide mine is road usage, but I like to play and it isn't used for commuting or motorways much, I also like to let it rev.

If mpg can be used as a metric to judge usage, I'm averaging mid 12’s to mid 14’s (and that's a 'large' UK gallon for anyone stateside reading this), I don't doubt that if I was mostly cruising at low revs and highway miles the can would catch a lot less oil :like:

WD :like:
That's me too. I don't track mine but when I let it out of the garage, it's driven to be enjoyed!

Thanks for the added info. :like:
 
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It's a good question. So this is where the PCV system is misunderstood, and why I'll probably do a video on it soon. The problem is to fully understand it, you sort of do have to go into it depth. Not that it's overly complicated though.

I will begin with this statement. Oil collected in passenger side separator is related to engine vacuum, not crankcase pressure.

Firstly, the PCV system is there because of emissions. Yes, a vacuum is great at pulling vapors, and having a 'free' scavenge system from the intake manifold vacuum is actually helpful. But without emissions, I think the design would be different. More on that later.

So the vacuum that is created by the intake is actually really strong. Imagine attaching a vacuum cleaner to the valve cover. That is exactly what is happening when the intake is under vacuum. This is why there is a PCV valve, and it's not just an open fitting. The PCV valve has a spring-loaded plunger in it, and it rest shut in two conditions. Firstly, when there is no vacuum ie WOT, it will rest shut. Secondly, when the vacuum is very high, the plunger will also shut. This is to manage the amount of air being sucked into the manifold at very high vacuum.

Now, at WOT, when the PCV valve is shut, there is no vacuum being applied to the valve cover. So any excess crankcase pressure will expel itself under atmospheric pressure. Nothing will suck it out, as is with the case under manifold vacuum. Also, because the PCV valve is shut, any excess vapors will be expelled primarily on the drivers side. As there is no vacuum, this becomes a vent, venting to the intake tube, but only under atmospheric pressure. It is not being sucked out. This is why you will get some oil on the intake tube over time, but usually not much. This is why there are driver's side catch cans, and in most conditions they don't collect anything. Now, if you had an excessive blowby issue, or a modified motor that had loose ring gaps, yes, you will get a lot more vapors coming out under WOT conditions, even to the point where they will push the pcv valve open to vent through there if it was needed.

This brings us on to race motors/built motors/big power forced motors. These will produce more crankcase pressure, due to how they are built, the power they are making, the rev range they are sitting at etc. Now the big thing is they don't have to comply with emissions, so using intake manifold vacuum isn't needed as they don't need to recirculate the vapors. So what you will see is two things. Either vented to atmosphere setups, or vacuum pump setups. Nothing beats a vacuum in terms of the amount of vapor you can pull over a set time, and that is why these pumps are used on big power/dollar setups.

So going back to your questions about vacuum being offset by increased vapors under WOT. Under WOT, on a normal or mild modded street motor, you will get some crank case pressure, but this will have to be expelled under atmospheric pressure. Again, this is why a lot of drivers side cans on mustangs appear to not collect anything. If you have normal crankcase operations and not excessive ring blowby, you will hardly see any oil vented without a vacuum. It will never compete with what the PCV system is doing, and this is pulling vapors under a strong vacuum regardless of what is happening inside the motor. Essentially, the reason you are seeing lots of oil in the passenger side on an OEM pcv system is not because of blowby or crankcase pressure, but because of vacuum. And because of this, the amount of oil on the passenger side will be related to each persons driving conditions, and the amount of time they stay in the intake manifold's vacuum range.
Thanks for adding your wisdom here, I certainly learned a lot from what you have written. :like:

This what makes forums so great, like minded people sharing their knowledge.
 
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Great write-up and pictures. Thanks for your efforts
Thank you.

I know this was a simple addition but I always go looking for these sort of tutorials when I want to tackle something. Hopefully my post will make installation easy for the next person.
 

 
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