PCV and Air/Oil Separator Question
01-08-2004 | 05:40 PM
#16
Rennlist Junkie Forever
Joined: Dec 2001
Posts: 5,978
Likes: 2
From: Los Angeles
NZ951
>>>If the oil gets put back into the engine, then all that is needed is a way to vent the pressure right? Then a filter and valve type system on the oil filler tube would suffice wouldnt it?<<<
No. It's not about "venting the pressure". It's about "drawing out" what's inside. Big difference.
If you do that, then you eliminate all all the pull that's provided by the turbo, to draw out and create a vacuum within the engine, which inturn helps to get the rings to seal and is worth some power.
TonyG
>>>If the oil gets put back into the engine, then all that is needed is a way to vent the pressure right? Then a filter and valve type system on the oil filler tube would suffice wouldnt it?<<<
No. It's not about "venting the pressure". It's about "drawing out" what's inside. Big difference.
If you do that, then you eliminate all all the pull that's provided by the turbo, to draw out and create a vacuum within the engine, which inturn helps to get the rings to seal and is worth some power.
TonyG
01-08-2004 | 05:43 PM
#17
Race Director
Joined: Apr 2003
Posts: 13,778
Likes: 5
From: New Zealand massive
Given that logic, the Linsdey kit is **** burgers? So it will need to be vented back into the inlet of the turbo, but without the oil, which is in the can which needs to be emptied, unless you can plumb it back into the engine somehow, how did you do it? Could it go back to the oil filler tube?
01-08-2004 | 05:48 PM
#18
Rennlist Junkie Forever
Joined: Dec 2001
Posts: 5,978
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From: Los Angeles
macnewma
The Greddy is pretty small. Typical race catch cans are much larger (1 quart or 2 quart, even 3 quart). I think the Greddy is 1 pint. It isn't very big inside.
On the track, it could fill up about 3/4 in a session.
And the reason I know this is because I ran it w/o it being drained into the engine sump in the beginning. After I saw this, I decided it was BS and that I didn't want to have to mess around with pulling it, draining it, cleaning up the mess, etc...
Much cleaner and simpler to drain the thing back to the engine sump.
I didn't comment on the Krank Vents. I saw the product, and it's nothing special. What's really amazing is that they were granted a patent on it. Maybe we should patent drinking water?
But what they said is true about creating a pull on the crank case.
The stuff they are selling is far too small for our applications. You need a catch can with AT LEAST a 5/8" ID line into and out of the catch can. And you want to run the largest catch can you can fit easily. That limits the size down quite a bit on our cars. And hence the Greddy choice.
Also, what I might change to is the Mocal air/oil seperator. It looks real nice. I just couldn't find one locally. Check them out. They are available in 1 quart and 2 quart (possibly bigger) sizes.
Steel Wool:
A screen keeps the steel wool in place. It's not going anwhere.
TonyG
The Greddy is pretty small. Typical race catch cans are much larger (1 quart or 2 quart, even 3 quart). I think the Greddy is 1 pint. It isn't very big inside.
On the track, it could fill up about 3/4 in a session.
And the reason I know this is because I ran it w/o it being drained into the engine sump in the beginning. After I saw this, I decided it was BS and that I didn't want to have to mess around with pulling it, draining it, cleaning up the mess, etc...
Much cleaner and simpler to drain the thing back to the engine sump.
I didn't comment on the Krank Vents. I saw the product, and it's nothing special. What's really amazing is that they were granted a patent on it. Maybe we should patent drinking water?
But what they said is true about creating a pull on the crank case.
The stuff they are selling is far too small for our applications. You need a catch can with AT LEAST a 5/8" ID line into and out of the catch can. And you want to run the largest catch can you can fit easily. That limits the size down quite a bit on our cars. And hence the Greddy choice.
Also, what I might change to is the Mocal air/oil seperator. It looks real nice. I just couldn't find one locally. Check them out. They are available in 1 quart and 2 quart (possibly bigger) sizes.
Steel Wool:
A screen keeps the steel wool in place. It's not going anwhere.
TonyG
01-08-2004 | 05:53 PM
#20
Rennlist Junkie Forever
Joined: Dec 2001
Posts: 5,978
Likes: 2
From: Los Angeles
NZ951
The lindsey kit is not trash. You can use it, and instead of using an oil filter, plumb that line back to turbo inlet.
>>>unless you can plumb it back into the engine somehow, how did you do it? Could it go back to the oil filler tube?<<<
I already told you! Remove the oil level sender (if your car has a pan that has this provision... I'm not sure if all early cars do... anyone?), tap it, and run your oil return line back into this. Simple.
It's a simple choice really: Oil Level Sender - vs - Oil Return
TonyG
The lindsey kit is not trash. You can use it, and instead of using an oil filter, plumb that line back to turbo inlet.
>>>unless you can plumb it back into the engine somehow, how did you do it? Could it go back to the oil filler tube?<<<
I already told you! Remove the oil level sender (if your car has a pan that has this provision... I'm not sure if all early cars do... anyone?), tap it, and run your oil return line back into this. Simple.
It's a simple choice really: Oil Level Sender - vs - Oil Return
TonyG
01-08-2004 | 07:24 PM
#23
Rennlist Junkie Forever
Joined: Dec 2001
Posts: 5,978
Likes: 2
From: Los Angeles
NZ951
>>>Ok, so not feasible to run a line that far from the guard, maybe with a valve going back into the oil filler tube...<<<
No.
If you do that, then you will have crank case pressure pushing oil back up the drain from the catch can, and you will be defeating the purpose in the first place, and probably be pumping oil out of the can.
The oil return from any catch can needs to be below the oil level in the pan.
TonyG
>>>Ok, so not feasible to run a line that far from the guard, maybe with a valve going back into the oil filler tube...<<<
No.
If you do that, then you will have crank case pressure pushing oil back up the drain from the catch can, and you will be defeating the purpose in the first place, and probably be pumping oil out of the can.
The oil return from any catch can needs to be below the oil level in the pan.
TonyG
01-08-2004 | 11:33 PM
#25
Rennlist Junkie Forever
Joined: Dec 2001
Posts: 5,978
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From: Los Angeles
>>>Any ideas where to mount a catch can when there is no room on the passenger side above the headers?<<<
1. Where the cruize control resides
2. Where the air box resides (if you have a MAF setup...)
3. Under the front bumper skin somewhere
4. Behind one of the front fenders (between the fender and the fender liner)
5. To the left (standing in front of the car) of the passenger headlight (like the a/c dryer but on the opposite headlight).
You have to be creative....
TonyG
1. Where the cruize control resides
2. Where the air box resides (if you have a MAF setup...)
3. Under the front bumper skin somewhere
4. Behind one of the front fenders (between the fender and the fender liner)
5. To the left (standing in front of the car) of the passenger headlight (like the a/c dryer but on the opposite headlight).
You have to be creative....
TonyG
01-08-2004 | 11:51 PM
#27
Pro
Joined: Sep 2003
Posts: 708
Likes: 1
From: PA
yes It needs to be above the oil level, gravity will let it flow back into the pan, I think Tony misposted his answer as if the return was below the oil level the oil from the pan will be forced into the drain, wait a second wtf? Allright now I'm really confused as the sensor is usually immersed in oil. Allright what's the reasoning of having the drain below the oil level?
01-09-2004 | 03:05 AM
#28
Rennlist Junkie Forever
Joined: Dec 2001
Posts: 5,978
Likes: 2
From: Los Angeles
I was correct.
The oil drain back has to be BELOW the oil level. Just like the oil return for the factory air/oil seperator and the turbo oil drain. BELOW.
If it is above, the crank case pressure will prevent the oil from draining properly and will blow the oil back up, and result in a lot of oil foaming in the catch can... which is exactly what you do not want.
With the oil return plumbed BELOW the oil level in the pan, gravity will still drain the oil out of the catch can, to the level that your return is located at the oil pan. In other words, the oil level in the pan, will equal the oil level in the return line.... exactly (at least on level ground).
And, as such, there will be a few inches of oil in the oil return line at all times (just like the turbo oil return).
Oil is neither created or destroyed (sound familiar? :-).... thus the oil level in the line (if it is returned to the oil pan below the oil level) will always remain at a constant level. Just like the oil in the pan.
Sounds backwards eh? But with the return below the oil level, the crank case pressure cannot blow the oil upward back to the catch can.
The only real issue, is that the oil level sender location is really not low enough in the pan. The oil return located there, could, under certain situations, be uncovered (cornering, or low oil level), which will unfortuantely, result in crank case pressure being forced back up to the catch can.
But since I don't intend to remove my oil pan just to tap it without a reason (new motor, new rod bearings, etc...), I'll keep my oil level up and live with it.
When the new short block goes in, the oil pan will be tapped at the bottom down low next to the oil drain. OR.. another alternative is to remove the large oil return from the turbo, have that line modified to accept the catch can return line, way way down low at the bottom.
Either way, that's really the right way. My way (tapped at the oil level sender location) is the best way as-is (just not the best way) :-)
TonyG
The oil drain back has to be BELOW the oil level. Just like the oil return for the factory air/oil seperator and the turbo oil drain. BELOW.
If it is above, the crank case pressure will prevent the oil from draining properly and will blow the oil back up, and result in a lot of oil foaming in the catch can... which is exactly what you do not want.
With the oil return plumbed BELOW the oil level in the pan, gravity will still drain the oil out of the catch can, to the level that your return is located at the oil pan. In other words, the oil level in the pan, will equal the oil level in the return line.... exactly (at least on level ground).
And, as such, there will be a few inches of oil in the oil return line at all times (just like the turbo oil return).
Oil is neither created or destroyed (sound familiar? :-).... thus the oil level in the line (if it is returned to the oil pan below the oil level) will always remain at a constant level. Just like the oil in the pan.
Sounds backwards eh? But with the return below the oil level, the crank case pressure cannot blow the oil upward back to the catch can.
The only real issue, is that the oil level sender location is really not low enough in the pan. The oil return located there, could, under certain situations, be uncovered (cornering, or low oil level), which will unfortuantely, result in crank case pressure being forced back up to the catch can.
But since I don't intend to remove my oil pan just to tap it without a reason (new motor, new rod bearings, etc...), I'll keep my oil level up and live with it.
When the new short block goes in, the oil pan will be tapped at the bottom down low next to the oil drain. OR.. another alternative is to remove the large oil return from the turbo, have that line modified to accept the catch can return line, way way down low at the bottom.
Either way, that's really the right way. My way (tapped at the oil level sender location) is the best way as-is (just not the best way) :-)
TonyG