Ok, not sure about this, I am just finishing building an 1835 and I am trying to work out if I need a breather box, its basically an new motor but I have been getting conflicting info on if I should install a breather box/catch can or not. My local VW guy is saying I don't need one and they will attract dirt in the area around the filter

I was thinking of installing breathers on the rocker covers to a breather box with a return to the oil filler and a couple of filters on the breather box.

Any info would be appreciated.

I get oil blown out of front pulley
so i put a home made catch can made from left over fence post
inside is stainless steel wool which i stole from my kitchen
no more oil out front... but mine has massive blow by because i didn't get a new pair of heads when i rebuilt it

I give up. How do old heads contribute to blow by?

Aso, how does a catch can reduce front leakage? Is it a pressurisation issue?

Cheers

Newt

old head might mean the rings don't seal as well, therfore combustion gasses enter the crankcase?? maybe?

and it is definately a pressure issue. if the crankcase isn't vented well enough, oil will leak through seals all over the place.

Heads have nothing to do with crankcase blowby, thats the pistons and rings. He might be referring to combustion leakage between heads and barrels???

Do we vent breather boxes or are they a closed system?

Newt

Vented i do believe.

Steve and Dave Carters bug has a good and explainable set up, i dont have any pics but im sure someone will have a good factory diagram, 68 autobug maybe.

I vent it to inlet just above the carb.

I don't know why i said heads when i meant pistons barrels set
I only replace the rings and bearings lol

what size jugs? on that 1835. if its 92mm theres your problem.

Yep they are 92mm pistons, I don't have any problem yet as I haven't fired it up yet just trying to find out anyone else experience and if its something I might need to look at doing,

In my opinion a breather box/catch tank is really only a band-aid solution, any streetable VW engine in decent condition shouldn't need one. The stock hose venting to the inlet is more than adequate unless you have fairly serious blowby issues. Also, bear in mind that venting crankcase gases to the environment constitutes polluting emissions, and therefore is generally illegal on cars built after 1971. On pre-'71 cars you may be able to get away with venting a breather box/catch tank to atmosphere.

Some vent into the air filter element like stock while other running more hypo motors vent the heads too, no just the oil filler location.

Check this post out .

http://www.shoptalkforums.com/viewtopic.php?t=118958&highlight= 

i also don't know why i said heads have anything to do with piston rings.... long night haha