crankcase ventilation

[rasmus westlin]

Hello!

I wonder if the crankcase ventilation must be taken from the valve covers or if it Will work like this. My plan is to make the valve covers smooth without breathers and i took the ventilation from the valley pan under the intake and then up in the air cleaner.

Will this work or will it build up pressure? Check my pictures. The hoose is 25MM, so it should be enough?

 

[DetMatt1]

Should work but I guess my biggest concern would be keeping the seal around that fitting on the valley pan itself.

 

[rasmus westlin]

Should work but I guess my biggest concern would be keeping the seal around that fitting on the valley pan itself.

Its sealed and i also made a splash plate under it so the oil wont splash on it.

 

[Chryco Psycho]

that will work but you need some vacuum to draw through a valve ideally .

 

[Steve340]

I do not think that will work out as you are likely to breath to much of the oil fumes back in to the carb and therefore polluting the intake charge coming in to the cylinders. It will ventilate the crankcase but I believe you will consume oil and foul the spark plugs.
Doing what you are planning I believe you would be better to go up to an oil catch can.
Ideally PCV is the best on a street motor.

 

[heminut]

25mm is really big for crankcase ventilation! That's about 1" and a 3/8" hose is what's usually used.

 

[Chryco Psycho]

On my 440 Duster I used a triple system , I had a 3/8 line connected to the intake through a PCV valve & then used a line down to each header collector to draw at high rpm , I had check valves in place so 1 system would close as the other took over . I split my valley pan in 1/2 at 7000 rpm with crankcase pressure at one point .
What you are building is what I would term a passive crankcase vent , not a Positive system where vacuum draws off pressure through a restriction [PCV Valve] , there is no issue with taking it from the valley pan instead of the valve cover but the system will normally have a vent / breather [inlet] & the PCV valve to draw out where your set up will have no inlet .