Dry sump Sec. Tank breather
Discussion
I've changed my engine breather and fitted a tank on bulkhead from rocker covers. My dry sump tank near the rear I've vented just with a pipe but it's pushing out a lot of oil on a run.. Tank was 2/3 full. Now half.. Anyone know why so much pressure on breather. I thought it would be negative pressure
This maybe it bit basic but I guess if there,s no incorrect question even a simple answer might be of value. Airflow on a dry sump goes into not out of the engine via the valve covers. then out of the engine to the drysump tank and then vented to a catch can with a breather. I have a catch can about 2 inches in Dia and 6 inches tall I drain about a cup of oil water crap about every 3000 miles when I do the oil change. Typically you want the tank to be over 50% and less than 2/3 full when the engine is running. Hope that helps. lee
If you have a large enough dry sump pump the only vent that you will need will be the dry sump tank vent. If you have only a 3 stage pump with 2 scavenge stages then the crankcase blow by will exceed the volume of the scavenge sections of the pump and excess air/oil mixture will look for anyway possible to escape the crankcase. If you have vents on the valve covers that will serve as a blow off.
This being said, I'm not sure I understand where you are loosing oil. If it is ending up in the vent tank on your bulkhead then adding a 3rd scavenge stage to your pump will cure it. After you get a large enough pump you can ditch the vent tank and use a vacuum limiting valve on one of your valve covers to prevent high vacuum (unlikely). Peterson sells a nice one.
This being said, I'm not sure I understand where you are loosing oil. If it is ending up in the vent tank on your bulkhead then adding a 3rd scavenge stage to your pump will cure it. After you get a large enough pump you can ditch the vent tank and use a vacuum limiting valve on one of your valve covers to prevent high vacuum (unlikely). Peterson sells a nice one.
Im running 3 stage pump one blanked off. Both rocker covers vent via tank above as in photo. The oil is coming from tank breather on dry sump tank. First off i just had a tube 12 inch long vertical and that pushed oil. Then i ran pipe from tank up roll cage to near top of clam. Still got oil but not as much..
Dom, If you have the standard 1 inch wide sections on your pump you need another stage. This is an easy addition when you return your pump back to the vendor. When the correct amount of scavenge is available the only vent on your system will be from the top of the dry sump tank. There should be a one way valve that looks like a valve cover breather that prevents pressure in the crankcase.
This is a good link on this subject:
http://nutterracingengines.com/racing_oil_pumps/cr...
This is a good link on this subject:
http://nutterracingengines.com/racing_oil_pumps/cr...
Gassing Station | Ultima | Top of Page | What's New | My Stuff