There's been a lot disinformation about the DOF whether intentional or not. Let me clear it up, again. The source for the DOF's oil is provided by Porsche right on the engine. We don't have to add spin-on adapters. The DOF's oil port is an M14x1.5 plug right on the engine. Here's a diagram from Porsche showing the oil flow in the M96/M97 engine. We've highlighted the route of the DOF flow in red to make it easier to follow: As you can see from the diagram: the oil flows from the oil pan (#1) Up the pickup tube (#2) through the main pump (#3) through the filter (#5) through the oil cooler (#7) and directly to the port on the engine (DOF Adapter) This oil is therefore filtered and cooled and does not pass over any other component in the engine where it can collect debris or other. It does NOT come off the cams (#8 & #11) and it does not rob oil from the cams or lifters. The oil feed comes off the oil cooler from where it's distributed to the lifters, cams and DOF each independently. We have tested the pressure losses to one side bank and the other with and without the DOF feed and we measure less than 2 psi difference at 60 psi working pressure. The DOF provides the open bearing with a stream of approximately 1 liter (1 Qt.) of filtered, cooled oil every minute, cooling the surfaces and as important properly lubricating them. The excess oil drops right back into the oil pan where it's mixed with the rest of the engine oil and goes through the system again. There is an oil pressure regulator valve that compensates and adjusts oil pressures constantly. If you record the engine's oil pressure you'll see that it's not steady or constant it fluctuates up and down depending on what the car is doing (accelerating, braking, turning, etc.). Our system has been duly tested in street and racecars for several years with great results using every type of common IMS bearing: OEM steel ball (single and double row) and new-style single row, aftermarket single and double row ceramic balls and aftermarket roller bearing. Our conclusion is very simple: The bearing is not the problem, it's the lack of proper lubrication! Also, for those who promote/rely on splash lubrication let me expand a bit here as well.
When the car has the correct amount of oil in the engine and is sitting in level ground, the IMS bearing is 25-30% immersed in engine oil.
Logical thinking would say: "Great! that's all the oil, I need!", but the truth is different.
First there's the law of Inertia. In these cars the IMS is placed front-to-back in the engine. On the Carrera, the IMS bearing is at the front, on the Boxsters and Caymans, because the engine is reversed, it's at the back.
So, when you accelerate and the oil is pushed to the back of the engine, there's no more bearing immersed in oil in the Carreras. The Boxsters do get a higher level of oil at the bearing under acceleration, but under braking it's reversed. The Carreras get more oil at the bearing, the Boxsters get none.
As you can see you can't state that the bearing is immersed. When it counts, when the engine is running that's not always the case.
Then, there's another law of physics called Centrifugal Force.
When the bearing is spinning at even 600 rpm (idle) the centrifugal force acting on the balls is such that ALL of the oil is ejected from the bearing completely and even if the car is on level ground the bearing gets no oil. Picture a full blender. When it's off the liquid is level. When you turn it on it creates a vortex where the center is drained of fluid because of centrifugal force.
The ONLY way you're going to get any oil into a spinning bearing is by injecting a constant stream under pressure to cool and lubricate it.
I hope this clears it up, if not, feel free to contact any of us and we'll offer whatever information you need to fully understand the Direct Oil Feed System for the IMS bearing in the M96/M97 engines. Happy Porscheing, Pedro