Breather system
Posted: Tue May 13, 2014 2:53 pm
Breather system on a Rover v8 with 4-barrel.
My system has a breather hole in each rocker cover. I’ve connected one rocker cover to the vacuum port of the carb with an in-line PCV valve. The other rocker cover has one of those little K and N filters on so is effectively open.
The PCV valve works because at idle there is a little “suck” on the rocker cover; not a lot.
My problem is a whiff and barely visible vapour from the little K and N on a hot idle. If I pull off the other rocker cover connection then vapour is visible out of both rocker covers. It looks like oil vapour and not exhaust.
OptionA: I can remove the K&N and connect to the underside of the air-filter. I didn't want to do this as I didn't want to contaminate the carb / air filter with oil. I was hoping that the tiny vacuum at idle would be enough.
OptionB: Restrict the K&N filter in some way / maybe a one way valve? Would this make a difference?
OptionC: Connect both rockers to the PCV. Would this cause oil leaks in the engine as the rockers would be under large vacuum at just off idle?
The problem is made more of an issue as the cabin cold/fresh air feed doesn't fit any more as the air filter is too large….so I get engine bay air into the cabin (not a major problem with the roof down I have to admit!).
My system has a breather hole in each rocker cover. I’ve connected one rocker cover to the vacuum port of the carb with an in-line PCV valve. The other rocker cover has one of those little K and N filters on so is effectively open.
The PCV valve works because at idle there is a little “suck” on the rocker cover; not a lot.
My problem is a whiff and barely visible vapour from the little K and N on a hot idle. If I pull off the other rocker cover connection then vapour is visible out of both rocker covers. It looks like oil vapour and not exhaust.
OptionA: I can remove the K&N and connect to the underside of the air-filter. I didn't want to do this as I didn't want to contaminate the carb / air filter with oil. I was hoping that the tiny vacuum at idle would be enough.
OptionB: Restrict the K&N filter in some way / maybe a one way valve? Would this make a difference?
OptionC: Connect both rockers to the PCV. Would this cause oil leaks in the engine as the rockers would be under large vacuum at just off idle?
The problem is made more of an issue as the cabin cold/fresh air feed doesn't fit any more as the air filter is too large….so I get engine bay air into the cabin (not a major problem with the roof down I have to admit!).