thats a std beetle engine , and air filter system.
yours isn,t

you said it was ok before you moded it thats why!

So. You don't think it's a coincidence?


Cause I don't have a mad monster engine, it a 1600, different cam, lightened flywheel etc and straight cut gears.  But certainly not a beast

Dan it could well be excess pressure the brass adaptors tend to have thick walls and thus restricted flow compared to a steel pipe.

looking where its splashed up is it your bottom pulley spewing it out.

This is very interesting....

I too have a standard engine and have the same carb Dan uses, my oil filler housing also
has a take off thats routed to my air filter...

But I have never had this happen, one thing thats different between Dans engine and mine
is that I am using the original filler neck and cap, it is different in that it has a catchment area
between the pedestal and the breather pipe, whereas Dan's pedestal has the small bore
(in comparison) tube connected directly to it.

All I can say is that there must be a pressure difference that is encouraging the oil to find its way
past the bottom pulley boss, if that is indeed where its coming from...

It does sound as though this breather has caused it though, as Dan hasn't had trouble before.

I would be inclined to take it off again and then run without it for a while to see if it all stops....

Does any of that make sense......

Peter

pressure will force oil out of the bottom pulley as it relies on a oil throw washer and a scroll on the pulley shaft to feed the oil back into the sump.
Fran probably blew his sand seal out at Le Mans with excess pressure as nothing can get past it due the a proper lip seal.

Hi Snoop 

Are saying that the use of these different ways to hook up to the oil filler can cause problems... ?

Does the standard VW set up change whats happening in there, as mine seems to 'catch' the oil and
allow it to find its way back with the breather tube (above) just venting oil mist and any pressure excess...

I was discussing this quite a bit with dan yesterday on the phone as I had what may/ may not have been an issue with that set up of breather. (To be honest I think it's more to do with carb air/fuel mixture - another story). But I was surprised how much oil was passing into the carb. Not so much as to be worried about, just surprising how much that's all.

Remember mine is a little more spec'd than dans, interestingly I have the same breather connection on the top of the filler - too narrow, could be the cause. But what was interesting for me was the amount of air coming out of the open breather when not connected. Certainly a constant puff whether on idle or revved. Never thought I had that much on the old type 3 1600. Compression test showed 130psi in each cylinder, mechanically still completely spot on (it only done 2k miles!!)

Dan was also shocked about the amount of air being pumped out of the breather, so may be as you guys suggest, narrow bore, length of pipe to filter is increasing crank pressure and forced oil out of bottom pulley. He said he was go run a few tests etc.

Quote from: Peter on September 07, 2013, 05:50:53 PM
Hi Snoop 

Are saying that the use of these different ways to hook up to the oil filler can cause problems... ?

Does the standard VW set up change whats happening in there, as mine seems to 'catch' the oil and
allow it to find its way back with the breather tube (above) just venting oil mist and any pressure excess...

Hp Peter,
Vw engineering should know piston blow by volumes be it by trial and error or maths then they know how big the breather has to be to allow the excess air volume out avoiding pressure build up and when folks modify engines these figures will change.
you can get complete seal rings like chord that reduce blow by on standard rings you have possibly a 15thou gap and air does escape into the sump every time it comes up and fires.

Well ....
Took the pipe off the air filter... The air that comes out is quite shocking.

Put it all back as it was and run it at 2-3000 revs on my drive .... no problem.
took it for a thrash round the block a few times ( its a big block  ). No problem

Well apart from I had brake fluid squirting on my feet through the bulk head and my resovoir was almost empty .... Oops !
So bought a new one today. ( never just one thing with VWs is it )

So looks like, my engine doesn't like the pipe back into the carb at all.
Engine is tested at 93 bhp so it's a bit more powerful than standard.
Very odd !

straight cut gears up the pressure abit too,but im sure its the pipe you have is too small bore you need half inch at least,ive gone over board on mine rocker covers ,oil filler dynamo stand and where ive blanked of fuel pedistal as mine revs to 6500 it moves alot  of air.

Thats good news Dan

It doesnt suprise me that there is a lot of air being moved what with 4 pistons
thrashing back and forth...

The restrictive and 'only' exit place is that fitting you had and its small bore...

The VW pedestal is a bigger area and it has an even bigger catchment box on the top,
the oil can separate and be trapped whilst any vapour or pressure can waft up the tube to the carb,
my 32/36 has no trace of much up there at all really....

So maybe thats it...

One thing ...... The elbow I used to join it to my air filter was the one that came with the carb.
The pipe is big enough to get my finger in. But the elbow is much, much smaller.
There was also no oil at all in the air filter. Not even a flick.

And ..... My air filter has really dense foam. Not sure it makes any difference though, just a point of bite.

That makes sense Dan......

'If' the oil was forced out past the bottom pulley, it was due to the restriction at the fitting on the oil filler cap.

You filter is 'upstream' of the restriction ans as such doesn't play a part in this!

At revs, the pressure that the four pistons create when they move toward the crankshaft is huge, the restriction
you fitted meant the oil was being forced out of the point of least resistance.

The bottom pulley uses whats called a 'Labyrinth' seal, its a 3 start thread, square sided and bottom, its helix
runs back towards the inside of the case when the engine is running.
There is a gap all round the bottom pulley boss and the case and the action of the multi start spiral (fast) causes air to be drawn in
and the thread form to catch and throw, any oil back inside the case.

ANY high pressure in the case due to restrictions at the filler area of the pedestal will cause oil to spew volumes out of this point.

Thats why the case breathing VW originally designed has large diameter bores, air can 'move' but not under high pressure.

Labyrinth seals are wonderful in that there is no contact or wear, so in a sense it lasts forever..... 

Does this make sense ?

Peter

Perfect sense Peter !



All cleaned up now and back as it has been for the last 4 years. ;-)


Now just need to change the brake master cylinder and finish the beetle ....
Oh did I mention my house is also on the market??.. So just a bit busy at the moment !!!