bk12

And I thought I would only have to deal with engineering dept. vs. marketing dept. debates at work.

BruceP

Not to split hairs, but from an engineering perspective the "number one priority" is actually cost which, yes, bears on profit, but it's kind of a different problem. Given free rein, engineers could design a car that was awesome at everything, including reliability and durability. But it would be so expensive that nobody would buy it. Every car, even a Bugatti Veyron, has stuff in it that was a product of "how cheaply can we make this non-mission-critical part so we can claw back the cost of that mission-critical part?". Marketing ends up getting involved in this stuff both because marketing has to figure out what price the car can be sold for and, with high volume manufacturers, what the consumer demands or will tolerate. Yes, Porsche makes the biggest unit margins on the planet. But they also only sold an average of 20,000 units a year or so of the 996. That has some real amortization challenges, which can only be solved either by pricing up (which they did as much as they thought they could) or cost cutting where they thought they could get away with it (which they did).

Over a beer, I bet I'd have some Toyota stories you, as an engineer, would enjoy. Their secret weapon, quality wise, is actually production engineering. They aren't brilliant design engineers; what they're brilliant at is engineering production processes. This, I suspect, is the real reason Porsche contracted them on the 996 project. You can only decontent a car so much in the name of margins. A company that had been building cars by hand for 40 years would need some help figuring out how find margins in production efficiency.

Oh, I forgot Toyota's other secret weapon: They leverage their high volume to play unbelievable hardball with suppliers. Try that on 20,000 units a year.

rdstemler

Where can I get one of those 100 mpg carbs??? Will they fit on a Porsche?? How many extra horsepower do you get?? What does it sound like???

Chads996

Greetings all:

As I am scouring the information online, I have come up with some leads to where theTech was getting his information. Interestingly enough, here is what I have found thus far:

Information sources:
Pelican Parts Online parts diagrams (Turbo Oil Return)
Porsche 996/C2/GT3 Workshop manuals

The following Diagrams describe the comparision between the two solutions:

Here is the X51 oiling Kit with the Dual Chamber Pump and oil line.



Here is the Turbo Return/scavenge pump and the location of the oil line. Note - the heat shield requires modification to make the components fit (this is the case with both the X51 & this version). The oil line may very well be a custom component fabricated to work. In my opinion, a braided / reinforced line will work nicely as would a custom bent and threaded tube. Actual factory parts may not be necessarily required to fit the line or make this work. Heat resistance would be advised due to its location next to the header.



Summary - Based upon visual clues, this certainly appears to be a viable option to this very talked about problem with the 3.4L engine. And as far as I can tell, the Turbo's pump would fit and fit in the correct orientation on the motor. Cost for this part could likely be around $450-600 each. And this does not include the machining of the valve cover.

More investigation will happen on Monday when I can speak with more detail to the Tech. I should have even more answers the deeper I get into this. My full intention is to do this modification and possible prepare kits (parts listings that others could use).

Oh, and before I forget...it is also VERY obvious that the use of the X51 oil pan with this mod is VERY recommended.

Stay tuned. More to come.

Chad

redridge

Chad...do you know what is driving this pump?

Chads996

The existing gear driven mechanism. It simply replaces the existing scavenge pump. The difference lies in the additional intake point for the oil line.

C.

redridge

Ok, now that make sense, seems simple enough. Does this scavenges the oil under braking condtion, since the oil is forced to move at the back of the engine? Is this the primary function of the extra port?

Benjamin Choi

starting armchair porsche QBs from the South!

Chads996

The oil scavenge pump works all the time, just like the central one in the oil pan. It is constantly working to move oil back to the primary supply. As long as the engine is running, it is running.

C.

gota911

Huh??

Chads996

Thread has been changed. Please see here:

https://rennlist.com/forums/996-forum/392583-1999-carrera-3-4l-oiling-modification-and-retrofit.html

C.