Ducman82

after more testing, i think the vac pump is overpowering the provent. time to build my own....

Fabio421

Overpowering how? Please elaborate.

Ducman82

To much air flow from the pump . I am using the provent "out" port as a fresh air intake, an oil/air is sucked in to a cam cover from the bottom oil return. The intake port has a little filter on it and It seems to be to low. So as the oil fills up it dribbles / puffs out under hard (high air volume from the vac pump) acceleration. Making a mess

Fabio421

I'm not really following you on your plumbing but why don't you have the port at the very bottom of the provent routed back to the sump?

Ducman82

If I route the return to the sump the line is to big ( using the return line for vacuum control) then I have poor vac pull on the crank case.

It works great except under hard load. Just needs se more tweaking.


Crank cast to pump, pump to provent, oil/fresh air to cam tower (circulation) fresh atmo air in to the provent from lower side inlet

Fabio421

If the pump is pulling air from the crank case and then pushing it into the provent, you don't have "fresh atmo air IN to the Provent" That would be pushing air OUT of the provent. Am I reading your post wrong?

Lizard928

The problem with the provent is that the air outlet is on the side instead of a the top.

It separates oil by flinging it out of the air against the wall, think tornado.

With the vacuum pump, the air speed is MUCH higher, and it leads to shall we say a wall of oil being carried around the outside. This wall of oil slowly builds up, until it fills the air outlet where it is able to escape.

danglerb

Only happens at high load sounds kind of like blow by, otherwise it would be rpm dependent wouldn't it?

IcemanG17

I have been doing a bit more research on ignition timing......when you are close to the knock threshold the blowby increases by HUGE amount.......

What is your timing advance? Have you tried reducing it? I know some guys ran as low as 26' at high rpm....which is about what the EZF was set for along with S4's

Hilton

Good to know the provent is being overcome - I was wondering about such a setup recently and suspected the small provent was just too small based on its rating.

Ironic.. using the vacuum pump and provent combo just moves the "oil plugging" issue around the system to a different point.

Presumably a simple dual-cyclone design similar to the one below would be a good option:

George604

Rings i got from my porsche bud in abq, he got them from his supplier (for the life of me i cant remember the brand, but it was in german)

Bjbpe

Given my advanced age, I rarely get the tach over 3500. In terms of equivelent age, my 87 is just as old as I am and I don't want either of us to meet our maker (God or Porsche,A.G.) yet.

Ducman82

going to check my Ign timing chart see what i have. whats a good max timing on a 5L 16v?