4. Improve the intercooler plumbing penatrations into the intake manifold. Andy's are prone to leaking boost.
That should keep you going for a while!


any pics of this?

 

I have an Andy keel intake and a few miscellaneous parts if anyone is interested.

 

Here are a couple of pictures of the front AN bulkhead fitting. Also, you can see one of Hans' fuel rail as installed.
The rear bulkhead fitting is similar but is not visible.

 

I guess this is a weak spot-


Your running an S3 configuration I assume

 

What is "S3" ?

 

what year car is your twin screw on?
where is your inter cooler?

 

That install is on Brian’s 87 ROW

 

The intercooler is in the manifold directly beneath the supercharger output.

 

Ah-
the position of your throttle linkage threw me off

 

At this advanced point in the supercharger development I'm curious about how people resolved the issue of crankcase venting.

Back in the day I installed a vacuum pump that pushed into a catch can which evacuated captured oil back to the engine through a small aperture line to a valve cover entrance. This system pulls from a cap on the original oil filler tower position and seems to move quite a bit of oil which is what I'm looking to reduce here.

What is the current wisdom on venting a supercharged 928?

 

Attached are some documents on crankcase ventilation, as well as a spreadsheet that I built to calculate crankcase breather hose diameter.

More details on the calculator: https://rennlist.com/forums/928-foru...alculator.html

This is how I did my setup (initial post, one iteration before final configuration): https://rennlist.com/forums/928-foru...her-setup.html

Final configuration (still running to this day with near zero oil loss): https://rennlist.com/forums/928-foru...l#post17984798

In short...large diameter oil safe hose coming off of the oil filler neck, tee into the passenger side valve cover ventilation ports, all sloped toward rear of engine with a high flow catch can (not a standard little can). Outlet of can is able to be plumbed back into intake, or to atmosphere.

There is a lot of science behind my design, plus several iterations to find the layout that works the best. But, even if you disagree with the science and theory, the results speak for themselves.

Net result with that setup is virtually no oil in the can to be drained, or any oil making it out of the can's ventilation outlet. 5-1/2 years now running about 1 bar of boost. Significant quantity of water condensation is captured in the can when running during the winter months. Which is why I do not run the can drain back to the oil pan. Because it would create an endless cycle of water build up in the oil. Even a heated catch can (the kind that uses coolant to keep the can warm) will not keep the water suspended enough to make it out of the can, especially in winter temperatures.

I drain the can at every oil change, and only find anything (water) in it if I'm driving it in the winter. Otherwise, it's always empty. I open and fully clean the interior and baffles in the can every third oil change. But, it's generally almost completely clean. Which shows that the crankcase ventilation is sized properly and from the right location.

Crankcase ventilation through the cam covers is dependent on the blowby gases making it up the oil drain back channels. Those channels are not big enough to let oil flow down and blowby flow up at the same time when at higher RPMs. Especially under boost, and especially if you have any knocks. So, relying on them and the OEM small orifice on the filler neck will overwhelm the system.

Just my personal experience having gone through several iterations of crankcase breathing setups.

 

Thanks for the information on your crankcase venting system. It is an approach quite different from the direction that I went, using the VP104 vacuum pump from GZ Motorsports pulling from the capped oil filler neck housing at the front of the block. This, of course, leaves no easy way to refill the oil at change time.

I thought that one of our group had modified one of the valve/cam covers to accommodate a filling access hole and plug. BUT I cannot find a reference to that in this thread, with the search engine.

Was there such a modification or am I just dreaming again?

 

You asked how people are doing it. Not sure why you asked if you didn't want to know?

It's actually a very similar approach, using large orifice/diameter pathways instead of vacuum. Otherwise, the same calculations and data applies. Which can be used to pick the vacuum pump and vacuum restrictor. The math is the same to determine volume of blowby.

With respect to filling, I've seen people using the second block off plate on the oil pan to run a fill tube directly to the pan. Filing through the cam cover ports would be pretty slow.

How about some sharing some photos, data and experiences with your setup?

 

Well, that's pretty presumptuous, to suggest that going another way would indicate a lack of
desire to understand the possibilities globally.
There are a number of pictures of my project in this thread. I may post some pictures of this particular project as it progresses if photo access is possible as the vacuum pump is buried where the old AIR pump resided.