i believe Bob mentioned that the part is not polished or buffed just anodized. These are faint tool marks from the milling. No reason to polish a part like this since it is not normally seen and polishing would not affect it's preformance in a positve way it would just be a waist of $.

 

Aloha Indy,
I'm not real sure. It would seem to me that the pump would have to work harder pumping oil from a vacuum to normal atmospheric pressure vs. just pumpimg oil with equal air pressure in the system. Try this experiment, seal a bottle of soda around a straw then suck through the straw. As a vacuum is created inside the bottle from the evacuation of soda, it will get harder and harder to suck. In this case oil is also flowing back into the system too, but I assume that there is also some air getting pumped out as well which would have to be vented on the other side of the check valve ? If not how does it work ? Maybe it's just a very weak transient vacuum. If you really tried to create a strong vacuum inside the case with say a electric vacuum pump, I bet the oil would boil away.

Oops Indycam's post went away.

 

you are correct - however for prototype parts it makes sense esp considering the quanity produced

 

The rough cutting of a chunk of ally goes really quick, its the final 'passes' or keller that takes the time. This particular part should be able to be cut on a three axis machine. Although many setups would be required due to the shape of the neck-fitting.

Definitely not cast..

If one really wanted to make these in high volume, a injection mold could be made (payoff after only a few thousand parts) using long fiber, glass plastic. The RC car industry has mastered this type of injection molding..

 

Indycam, I think it would be interesting to get manometer data from the case with and without the device to see what the pressure change is. Plenty of aircraft engines operate fine at high altitude so the oil boiling is likely not a factor at all. If you could get the inside of the case at say 30k feet altitude air pressure equivalent, air resistence would certainly be diminished for the moving parts inside the case. The oil pump would have to do more work under negative pressure, and just working across a check valve, but maybe that is not a significant problem.

 

I like it. Thanks for sharing the part.

I would not have guessed the diff would be that drastic, but from reading about the mods internally for the air its not unbelievable. Looking forward to seeing more stuff.

Ah the possibilities of good and bad could form a thesis and this is just 1 part! I love cars.

 

On the motor.

 

I personally found the absolute best and cheapest way to dramatically improve the performance of my 964 is to leave the wife at home! Lots of weight reduction and no PAX instructions.

 

 

I would have thought that a reduction in pumping losses would give a power increase very dependent on rpm.Sounds like 5bhp @ 7000 and maybe 2 @ 4000.In a dry sump motor, oil pump pressure/scavenge ratio + ring blow by etc,etc is likely to turn this simple idea into something potentially trickey on STREET motors.It will be interesting to hear real life experiences on this one.

Geoff