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Posted by: mtc911 Apr 20 2020, 09:40 PM

So, I have researched this one quite a bit and i cant seem to find the right answer. I have a “built” 2056 with Dual Weber Carbs. I “believe” it is a 1.7 Case with 2.0 Heads on it - not 100% sure there but the engine number seems to indicate that.

Anyway

I have (2) the little Crankcase Breather Filters - one on the driver side and one on the oil fill (seen in the pictures). However there is nothing on the passenger side head. On the drivers side there is a T/splitter type thing that also pulls in a port out of the fan shroud.

Obviously these little filters are making an oily mess in the engine bay - nothing too tragic but i would like to get rid of it if possible. I have been looking at the little Cans by Empi and Scat - that look like they would work. But I’m still kind of confused.

1 - Why would I have one of these on the Driver side Head and not the passenger side?
2 - If i install one of those cans should i route the port off of the fan shroud into it? I have read both yes and no on that question in my research.
3 - Will the can really even help reduce the oil in the bay? I have read yes and no on that question too
4- attached diagram is what i was planning to do with the breather box - is this correct?
5 - is there any downside to using one of these instead of the little cheaply filters?

I have read a ton of posts on this in various forums and I cant come to a conclusion. Yet.

Thanks

Posted by: falcor75 Apr 20 2020, 10:51 PM

I would start with removing the tube connected to the fan shroud. That is the air output for the carbon cannister and should not be connected to the crank case breathing system. Its most likely a big part of your oily mess since it takes fan air pressure and helps to push oily air out thru the little filters.

Do you not have a port at all on your passenger side head? Thats a bit wierd, maybe the heads are from different years? If you still want to do the catch can thing I would want to connect both heads and the oil filler tower.

Posted by: Mark Henry Apr 21 2020, 06:18 AM

The EMPI breather boxes are crap.
You need a sealed box;
-hose on the bottom drains back into the case or puke bottle.
-hose in the middle is from the case breather tower.
-hose in the top to a carb.
I'd just plug the head vent.

On my bug I used a EMPI breather box but I milled off the lid tit's and sealed the box with sealant. I remove the foam and bend up the metal screen so that it catches vapours. I then mounted it vertically with the now bottom draining back to the case and top vented to a carb. I drill extra vent holes in the middle and use breather vents.

Posted by: mtc911 Apr 21 2020, 08:56 AM

When you say “remove it” you man just leave it open or plug it with something. Seems like you would want that fan shroud port plugged, no?

Posted by: brant Apr 21 2020, 09:09 AM

you can plug it
its going to be a small amount of clean air... being pushed by the fan
it will hurt nothing to leave it unplugged... its just positive pressure air

but the crank case is also expelling positive pressure
thus the reason you do not want those two connected together
the fan air is pushing the crank case pressure back into the case
the opposite of how a crank case breather is supposed to work

probably that lack of released pressure can just come out another breather on the motor

but ultimately, the lack of a proper crank case breathing system creates leaks and other problems.

disconnect it

Posted by: maf914 Apr 21 2020, 03:03 PM

Hoffman Automotive Machine (HAM) has a good article about venting on their website. This may help.

https://newsite.hamheads.com/2016/12/10/type-4-crankcase-breathing-system-tests-analysis/

Posted by: mtc911 May 3 2020, 12:27 PM

So, since the head vent was already there and i was getting kinda oily mess in the engine compartment..i bought this cheapy canister thing...vented one head (because the other one isn’t? Which is still kinda odd - and just ran a T of the oil fill tower...just to use all 3 ports...test drive showed no oil blowing out around the oil fill - or anywhere else...didn’t notice any change in oil pressures or anything...it was a cheap way to test it out...and with nothing better to do since we’re not supposed to leave the house...heck ,it was something to do

Posted by: barefoot May 3 2020, 03:10 PM

I interconnected the head vents together (somewhere heard Jake recommended that) and used a low height vent canister with one vent to air filter and bottom to oil fill chimney. This sits high enough to insure draining to the chimney.
I get no oil staining into the flex hose to the air filter and everything stays clean.
2 extra ports on top left capped.