questions were aimed at gestalt1, who has an accusump in what looks liek a race car, not a street car

and most folks, if not all on this thread, so far has said, no use, oil pressure on startup is good on a 911

and i mentioned 2 times, that oil temp , warmup, is way more important...

flogging a dead horse here

Obviously, we can rationalize most any Porsche related gizmo but if you are trying to "extend the life of you motor" by using an AccuSump you are wasting your money IMO. The bottom end of these motors is already one of the last things to wear out. (As long as the squirters aren't blocked.) Tear a few apart and you'll see.

The valves guide are the first to go and no amount of pre-oiling is going to make them last longer.

In my non-expert opion, heat is the enemy of these motors. The air/oil cooled heads on our motors have pretty poor thermal control compared to a water cooled car. The valve guides (and even the valve springs) suffer as a result.

Put a fan on you oil cooler if you are seeing hot temps in traffic and change your oil more often.

-Chris

Stijn, i have not finished my car yet so i really can't comment on the functioning of the accusump in the real world. it does store oil under pressure, when there is a drop in pressure it releases this extra oil. when the pressure is built back up the accusump re-stores the oil for the next time the engine oil pressure drops. i went with it because it was cheaper than a custom oil tank and it is plumbed directly to the main oil galley. i don't think it is needed on a street car, mine is a barely street legal race car.

How much are they?
Gestalt - looks like a nice install!

Doug

Accu Sump
 

Here is the address. I estimated that it would cost about $450 for everything. http://www.accusump.com/

Assuming you use the automatic control switch, which would allow you pressure in the event oil starvation in the tank:

What happens at low engine speeds and oil pressures when it dumps an extra 2 to 4 qts of oil into the system? My engine idles at low pressure, probably low enough to trigger it pressurizing the system.

That much extra oil would probably overfill my tank or at least cause a bunch of oil to end up in the intake.

Doug

i think i got the accusump for $280 with the electric valve. the an-8 hose, ends and adaptors is about another $100.
-matt

I read the lowest threshold switch operates at 20 to 25 psi. If you engine idles at or below, it will dump oil into the system.

Let's connect the Accu Sump to the Off-Topic thread area and let it pump away...

Actually, let me add my .02 to this discussion before we decide it's not worthy of inclusion in the main forum.

For a few seasons now I have been racing my 911E on Hoosiers.

Porsche braking being what it is, I have seen braking forces well in excess of 1g on my DL-90 data logger.

As was correctly stated above by Wil, this kind of braking causes the oil in the tank to slosh away from the supply port, which is located in the rear of the tank.

I have an adjustable low oil pressure light which is set at 20 pounds. Under hard braking, the light illuminates frequently. NOT good for the pressure pump or bearings to be starved for oil.

The correct location to plumb the Accusump is into the oil pressure port next to the engine thermostat. This connects to the main oil gallery. The fact that Porsche measured the oil pressure originally here, and then moved the pressure sender to the other end by the chain box cover so they could install an oil pressure idiot light by the thermostat is immaterial.

That's all well-known. Now to conjecture.

My BELIEF is that plumbing an 18x1.5 fitting to the port and then running a line to the Accusump would smooth out the pressure fluctuations, with the side benefit of pre-oiling. The thing about race cars it that they tend to sit in storage for long periods over the winter (well, mine does) so being able to pressurize the system after a few months is helpful.

HOWEVER and it's a big However, this installation is unsuitable for owners of Mechanical Fuel Injection cars . . .BECAUSE. . .

There is a banjo fitting on the port for the pressure sender that sends engine oil pressure to the MFI pump inlet. While there is a small-diameter orifice in the inlet to the MFI pump, it's still a calibrated leak, which would cause the pressure to bleed down. For carbureted cars, I wouldn't hesitate, but for MFI, not a very good idea. In addition to the difficulty of plumbing everything.

Now, why not convert the pump to have no oil from the engine a la RSR? Well, I asked Gus about that very thing, and it's a very expensive modification. If you fill the pump with oil and plug the supply and return lines, and don't provide the vent on the top, the pump will pressurize and blow the oil out. So the red vent must be installed. (Gus says this was originally done on engines with "a lot of vind in ze crankcase" i.e. the pressure fluctuations in the crankcase would blow the oil out of the pump through the return line.

Also, if you plug the oil lines, you will have to remove the pump every time you want to change the oil in the pump. Removing the pump is about a six on the Scale of Inconvenience, with under-dash electrical work about a seven.

SO where does this lead us? I have an accusump for sale, manual valve, never even been out of the box. I would take $150 not including shipping from the first private message accepting my offer.

Good luck!

john is right, an accusump will not work with mfi. I'm using an efi system so i don't have that problem. just to clarify, on my sc case the oil pressure warning sensor is a 10mm, not 18mm. the pressure guage sender is 18mm. the 10mm is very small compared to the 8an hose (and the 8-an is on the small side of what is reccomended). i'm not sure this is important because i've seen it plumbed into the case this was and there aren't other options really.

The M10x1.0 VDO sender threads into a fitting in the case. The threads on that "reducing socket" are M18x1.5 if I am not mistaken.