Re: Oil breather
Posted: Mon May 25, 2020 2:32 pm
There is another thread on catch cans not so far back where I asked what everyone is using. Might be worth having a look.
Why a catch can?
Problem with older engines where a pipe connects rocker cover to airbox is that if there is a lot of oil mist/vapour, it is sucked into the engine and with individual ports, the port nearest the intake has to burn the stuff that often fouls the spark plug.
Problem with even older engines that vented to atmosphere is that wherever the mist/vapour exits - usually under the car - gets messy with a build up of oil mist. Then there is the environmental damage.
So a catch can will get rid of both these issues.
A neat but expensive can is a Mishimoto. https://www.mishimoto.eu/?gclid=EAIaIQo ... gKNp_D_BwE It has a baffle mechanism inside that goes a long way to separate the oil mist into air and oil, retaining the oil and allowing the air to leave through a small airfilter.
Better still, vent the catch can outlet into the exhaust pipe where the exhaust will pull the air out of the tank and burn it. Described above by using a disused O2 sensor, but better still use an agled entry into the exhaust where the capillary pull will be greater: https://www.ebay.co.uk/itm/Universal-St ... SwgPVcljXW.
Do note though if you do vent into the exhaust you must fit a one way check valve as close as possible to the point you enter the exhaust pipe. It must be a valve suitable for the job and not a high spring fuel delivery type valve: https://www.mishimoto.eu/performance-ch ... e-3-4.html This prevents any back pressure from the exhaust getting back into the rocker chamber and acts as a flame arrestor. Finally you should have some stainless gauze stuffed into the pipe as well.
If your engine bay is tidy and the car belly is clean, then a catch can is a must...
Why a catch can?
Problem with older engines where a pipe connects rocker cover to airbox is that if there is a lot of oil mist/vapour, it is sucked into the engine and with individual ports, the port nearest the intake has to burn the stuff that often fouls the spark plug.
Problem with even older engines that vented to atmosphere is that wherever the mist/vapour exits - usually under the car - gets messy with a build up of oil mist. Then there is the environmental damage.
So a catch can will get rid of both these issues.
A neat but expensive can is a Mishimoto. https://www.mishimoto.eu/?gclid=EAIaIQo ... gKNp_D_BwE It has a baffle mechanism inside that goes a long way to separate the oil mist into air and oil, retaining the oil and allowing the air to leave through a small airfilter.
Better still, vent the catch can outlet into the exhaust pipe where the exhaust will pull the air out of the tank and burn it. Described above by using a disused O2 sensor, but better still use an agled entry into the exhaust where the capillary pull will be greater: https://www.ebay.co.uk/itm/Universal-St ... SwgPVcljXW.
Do note though if you do vent into the exhaust you must fit a one way check valve as close as possible to the point you enter the exhaust pipe. It must be a valve suitable for the job and not a high spring fuel delivery type valve: https://www.mishimoto.eu/performance-ch ... e-3-4.html This prevents any back pressure from the exhaust getting back into the rocker chamber and acts as a flame arrestor. Finally you should have some stainless gauze stuffed into the pipe as well.
If your engine bay is tidy and the car belly is clean, then a catch can is a must...