Oxy crankcase ventilation

[grelland]

Guys,

Looking for some advice on crankcase ventilation.

For the last couple of seasons, I have run a very simple setup with a Berg breather box and a AN-10 hose to an adapter in the distributor hole in order to balance the left and right side case halves:

last year.jpg

I am planning a change in the air filter setup, so I will not be able to fit the Berg tower any more.

So to the question:

Is this left-right case half hose really necessary? Can I get away with using a simple oil filler like this:

filler.jpg

And then a breather box/catch tank on the firewall?

Are there any other considerations with an oxy case vs standard type1?

[bug66]

Put that filler tube in a lathe. Turn it down to 40mm, use 40mm hose to a custom breather box with a 40mm airfilter from Biltema..

[flat4olsen]

My engine is pretty much identical to yours. I vent from the valve covers and from the oil filler (I run an OEM Mexican generator pedestal) to a breather box on the firewall. No problem with excessive pressure or oil leaks. I think you will be fine with the oil filler shown above.
Don´t throw your Berg breather away. Just send it to me, and let me throw it away for you

[grelland]

Hehe. Thanks guys. No need to overcomplicate then

Just for curiosity, flat4Olsen. Is it necessary to vent the valve covers? I have not done that on any of my last builds.

[flat4olsen]

I honestly don’t know. Some say yes and some say no. It can’t hurt, so I just did it to be safe.
Do you want my address so you can send the Berg Breather?

[grelland]

[bug66]

The logic of not breathing the valve covers are that the oil shall go down the 4 push rod tubes. Not the ventilation.

That little breather nipple is no way near enough. A stock 1600cc Type 1 engine has a lot more ventilation..

[bug66]

And it does not matter if the breather box on the firewall is large, if the bottleneck is at the engine side..

[flat4olsen]

I am not going to argue about the logic of breathing the heads. As I said, I don’t know if it is needed. I know Porsche did it on the 914 with 2.0 l engine, and I think they did it for a reason. If it works for Porsche I have no reason to question the funktionallity.

[bug66]

Did Porsche vent both sides, or just one side?

One side fills up with oil, the other doesn't..

[flat4olsen]

Both sides. http://www.shoptalkforums.com/viewtopic.php?t=128604