cam cover blowby flow and crankcase pressure, tiny hole modification
#30
Former Vendor
iTrader: (31)
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 15,442
Total Cats: 2,100
Jason, any updates? I am considering plugging both of the factory ports and drilling through the top of the valve cover on both sides in order to get the breather ports up as high as possible (and away from liquid oil).
#33
High pressure carries oil better than low pressure. Adding scrubbing material lowers the volume, therefore increases pressure (main reason why Julian's first try with lots of scrubbing material ended badly). In my opinion scrubbers is a temporary thing that works good in the beginning, then bites you in the behind once it gets soiled as then it helps carry the oil. From what i can find, the only reason people choose not to use a catch can is that they have to empty it. Why not add a bottom to top fed catchcan so the oil can drain back after the motor is turned off?
#34
Sav, if you do that you have to add your own baffling, e.g. use the "real" oil catch can linked to in the other thread with bbundy's pics. I think it's better to modify the factory baffling.
I haven't driven the car in weeks, I've been doing a lot of little odds and ends while waiting for the weather to turn nice (which it just did).
I haven't driven the car in weeks, I've been doing a lot of little odds and ends while waiting for the weather to turn nice (which it just did).
#36
Let me try to explain it with an example.
You put a 5 foot diameter fan at the end of a wet tunnel. Hardly any water will move. Now you take the tunnel and fill one side of it with bricks so now the tunnel is only let say 3 feet across. You can see that same fan in the beginning will start moving air across at a higher velocity and it will now push the water around.
The velocity and pressure increases in the 2nd case. More of the water moves.
#37
Former Vendor
iTrader: (31)
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 15,442
Total Cats: 2,100
Sav, if you do that you have to add your own baffling, e.g. use the "real" oil catch can linked to in the other thread with bbundy's pics. I think it's better to modify the factory baffling.
I haven't driven the car in weeks, I've been doing a lot of little odds and ends while waiting for the weather to turn nice (which it just did).
I haven't driven the car in weeks, I've been doing a lot of little odds and ends while waiting for the weather to turn nice (which it just did).
I don't want to return the blowby waste to the sump - I know what it looks like and I don't want it anywhere near my bearings/turbo.
triple88a, the scrubbers work by giving the oil vapor lots and lots of surface area to pass over, which turns the vapor into liquid oil and stops it from being carried into the vent tubes.
#38
Elite Member
iTrader: (2)
Join Date: Jan 2007
Location: Los Angeles, CA
Posts: 8,682
Total Cats: 130
I'm going to drill into the factory baffle chambers, but instead of having them on the sides ala factory (and very close to the floor of the baffles, where I'm sure liquid oil sits and pools) I'll put them on the ceiling of the chamber, which will hopefully promote less liquid flow (and thus more airflow). I don't care as much about the aesthetics of such a change as others might.
I don't want to return the blowby waste to the sump - I know what it looks like and I don't want it anywhere near my bearings/turbo.
triple88a, the scrubbers work by giving the oil vapor lots and lots of surface area to pass over, which turns the vapor into liquid oil and stops it from being carried into the vent tubes.
I don't want to return the blowby waste to the sump - I know what it looks like and I don't want it anywhere near my bearings/turbo.
triple88a, the scrubbers work by giving the oil vapor lots and lots of surface area to pass over, which turns the vapor into liquid oil and stops it from being carried into the vent tubes.
Are you going to drill into both intake and exhaust side? I am thinking about just doing the exhaust side and porting out that middle-exhaust baffle connecting hole. The exhaust side baffle is so much more extensive and it's um, better baffled.
#39
When you decrease the volume but you keep the same flow, more oil will be carried away with the direction of the air flow.
Let me try to explain it with an example.
You put a 5 foot diameter fan at the end of a wet tunnel. Hardly any water will move. Now you take the tunnel and fill one side of it with bricks so now the tunnel is only let say 3 feet across. You can see that same fan in the beginning will start moving air across at a higher velocity and it will now push the water around.
The velocity and pressure increases in the 2nd case. More of the water moves.
Let me try to explain it with an example.
You put a 5 foot diameter fan at the end of a wet tunnel. Hardly any water will move. Now you take the tunnel and fill one side of it with bricks so now the tunnel is only let say 3 feet across. You can see that same fan in the beginning will start moving air across at a higher velocity and it will now push the water around.
The velocity and pressure increases in the 2nd case. More of the water moves.
Yes the velocity is increased by the scrubbers, but the scrubbers present a lot of surface area to "catch" the oil vapor. That's the theory anyway.
But if the scrubbers do make things worse instead of better, a better scheme would be baffles that cause the oil to zig zag, so when the gas zigs, the oil doesn't and hits the wall and drains down. Or use a BMW style separator, which makes the gas flow in an ever decreasing spiral (they call it a "cyclone separator).
#40
Although the color variety of those scrubbers is absolutely fantastic...
What about trying some fuel cell foam (http://www.summitracing.com/parts/SUM-290190/?rtype=10) instead? It seems like that foam would catch the oil better. I would use it only in the beginning of the baffle because it seems like the fuel cell foam would be worse in regards to the "velocity argument " where it could assist the oil in reaching the breather port.
I'm almost positive the fuel cell foam is polyurethane foam with a maximum temperature of 150-250°F which may be a bit low for this application. McMaster has polyimide foam that's rated for 400°F but they only sell 24"x48" sheets where 1/4" thickness costs $45; 1/2" for $80; 1" for $125; 2" for $210.
What about trying some fuel cell foam (http://www.summitracing.com/parts/SUM-290190/?rtype=10) instead? It seems like that foam would catch the oil better. I would use it only in the beginning of the baffle because it seems like the fuel cell foam would be worse in regards to the "velocity argument " where it could assist the oil in reaching the breather port.
I'm almost positive the fuel cell foam is polyurethane foam with a maximum temperature of 150-250°F which may be a bit low for this application. McMaster has polyimide foam that's rated for 400°F but they only sell 24"x48" sheets where 1/4" thickness costs $45; 1/2" for $80; 1" for $125; 2" for $210.