Turning the pollution cap into a crankcase vent

As most of you know iam in the process of my own little build. Anyway it was suggested that i might want to consider running another crankcase vent for more ventaltion. So i thought about turning my plugged off smog covers into a crankcase vent. I just thought about drilling some holes in each emmision port and allow it to run out hoses. Anyone did anything similar? or any tips or advice? Thanks, Eric

I think those have one way reed valves that let air into the exhaust. I wouldn't mess with them.

I already have them plugged off. right now i dont even have the reed valves in i did wonder if i could flip them over and use them?

Good Fortune!

Maybe iam misunderstood. I have a j model head on my mk11 motor. I have already plugged the head to block off the emmission ports. It was sugested that i need more crankcase vent. I still am running stock crankcase vent on the top of the crankcase.But i wanted to drill out the valve cover inside the old emmission housing and possibly flip over the reed valves so the air can be pushed out the cover and thru the emmission port on the valve cover. Turning it into a crankcase vent for extra ventaltion. I just worried about oil get pushed out there. And wasnt sure if anyone else has done this. Or if anyone had a any tips. Thanks, Eric

I don't see why not.
Like you said, oil getting pushed out by the spinning cam.
Maybe some sort of trap with a screen.
Or would it be more effective on the cam chain tunnel?

Powerstroke_fan wrote: Maybe iam misunderstood. I have a j model head on my mk11 motor. I have already plugged the head to block off the emmission ports. It was sugested that i need more crankcase vent. I still am running stock crankcase vent on the top of the crankcase.But i wanted to drill out the valve cover inside the old emmission housing and possibly flip over the reed valves so the air can be pushed out the cover and thru the emmission port on the valve cover. Turning it into a crankcase vent for extra ventaltion. I just worried about oil get pushed out there. And wasnt sure if anyone else has done this. Or if anyone had a any tips. Thanks, Eric

The factory did it already. All the stock emissions components will work. The only difference is you're not allowing the crank case gasses to be sent to the air box first. Hook it up directly to the crank case vent instead. You would want some baffeling in place to prevent sucking oil into the exhaust system. The stock airbox prevented that.

The OEM version allowed the gasses to be pulled into the carburetors where they partially diluted the mixture. Didn't really hurt much of anything.

The exhaust system sets up a very strong depression at and for a short time after TDC on overlap. It's actually a stronger depression than the piston can create on it's downward stroke.

When I was into boosted cars a buddy told me this was done quite frequently on Toyota Supra's. They just reroute the crankcase vent straight to the exhaust after the turbo. There were a lot of guys that claimed to gain hp but I never saw a dyno graph to prove it. I don't remember if they did anything to stop oil from being sucked into the exhaust but you can always get on a Toyota forum and do a search.

Dont have a smog cover , but on my 78 1000 I took a 90 degree half inch fitting and welded it to the cam cover . Its locsted on the right side of the cam chain tower pointed out the back. My hose runs to the swing arm chain guard to a point behind the front of the rear tire . very little oil comes to this point but if it does it dumps onto the drive chain. Or do the same and run it into a catch can ( beer can ). I did mine to help control excess crankcase pressures as my motor runs lots of boost.

Powerstroke_fan wrote: As most of you know iam in the process of my own little build. Anyway it was suggested that i might want to consider running another crankcase vent for more ventaltion. So i thought about turning my plugged off smog covers into a crankcase vent. I just thought about drilling some holes in each emmision port and allow it to run out hoses. Anyone did anything similar? or any tips or advice? Thanks, Eric

I have done a few.
I block up the ports in the cover that usually align with the ones in the head then open up some holes in the bottom of the emission chambers directly into the head.
These are positioned right above the camcaps so they are shielded from any direct oil splash.
I remove the reed valves and fill the empty chamber with some stainless gauze to catch the oil mist.
You can then run some hose from the cover to a catch tank, vent fiter or whatever.
I have a MK2 cover i have just done if you need pics.

uh er,yes sir could we see the pics !

leon

i too need pics as im trying to figure out how to vent mine that are stock except ran to eachother to the rear and to a catch can.