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Posted by: MikeSpraggi Jun 16 2009, 02:21 AM

I'm thinking of adding an Accusump Oil Accumulator to my project DE/track car. The interior will have 2 seats but I would like to mount the accumulator so I can manually control it when starting the engine.

The one car I saw had the accumulator installed where the passenger seat is/was located so the driver could control it while strapped in. With two seats in my car, where else have any of you seen these units located? Thanks

Race car this weekend at Watkins Glen with Accusump.

Posted by: messix Jun 16 2009, 02:35 AM

mount it the engine compartment and use this http://www.cantonracingproducts.com/cgi-bin/commerce.cgi?search=action&category=2425

Posted by: jt914-6 Jun 16 2009, 04:45 AM

Got my 3 quart mounted in rear trunk with the 12 volt solenoid.......

Posted by: carr914 Jun 16 2009, 05:57 AM

Go for the electronic solonoid vs the manual and put it anywhere you want (the rear trunk is a nice spot)

Accusumps are such a nice addition to a Type4. I probably need to dig mine out & sell it, since I haven't had a 4 cylinder in years.

T.C.

Posted by: degreeoff Jun 16 2009, 07:16 AM

Mike has a six though....if one does not start the car for a week or so is it still ness on a six?

Posted by: carr914 Jun 16 2009, 08:00 AM

Wet-Sump vs Dry-Sump. The 911 engine is full of oil

T.C.

Posted by: MikeSpraggi Jun 16 2009, 09:35 AM

The track car I saw was a six. The reason this came up was I noticed the race car had the oil tank mounted where the gas tank originally sat which, is what I'm doing.

I asked if there were any problems with the front oil tank arrangement that they could alert me to. I was told during hard cornering, initially the car had experienced momentary oil starvation at times. They use the Accusump to maintain a constant oil feed and since installation, have not exeperienced starvation or loss of engine due to lack of supply. I understand that it can also help when starting the engine, but hey, that's why I'm asking .

Posted by: charliew Jun 16 2009, 11:27 AM

Be sure and use a minimum of .500 lines (10/12an is a lot better) and the closer to the motor the better. Also the short lines will cost less. Long lines on anything including air loose pressure. More volume means more pressure with the end of the line open. You need at least 10lbs per 1000 rpms, ie 7k at least 70 lbs pressure. The switch and lines will probably cost as much as the accusump.

Posted by: sww914 Jun 16 2009, 12:27 PM

Don't mount it in the passenger compartment. Mine blew up once and shot 2 quarts of hot oil everywhere. It was in the engine compartment and I'm really glad it wasn't right next to me.
My situation was a combination of small problems that led to it's failure, but still you don't want that thing next to you.

Posted by: SLITS Jun 16 2009, 02:10 PM

First, if a six needs an Accusump (hydraulic accumulator) there is something wrong in the installation of the dry sump tank. The tank outlet should be higher than the inlet of the pump to INSURE a flooded suction line.

And that's all I have to say about that!

Posted by: mudfoot76 Jun 16 2009, 02:38 PM

I have a 2qt mounted in the rear trunk, an10 lines. My type4 is very happy with oil pressure when on the track.

Posted by: smj Jun 16 2009, 03:21 PM

I'm picking up a variety of opinions -- shocking! I've got an Accusump from the 944S I retired, sitting around doing nothing. I thought it might eventually be useful in a teener.

Sounds like everybody feels a Type IV benefits from an Accusump, but a 6 with a well positioned oil tank shouldn't for street applications, might for track applications.

Fair summary?

I believe my -6 will only see the track a couple times for grins, and will be setup for agressive street use. So it looks like I won't need the 'sump there, when I finally get around to cleaning it up.

Posted by: Matt Romanowski Jun 16 2009, 03:41 PM

No 6 cylinder car needs an accusump. If a dry sump car has an oil starvation issue, there is another problem that needs to be fixed. An accusump is never needed on a six.

Also, the 10 psi per thousand guidline is only up to about 50 lbs (at 7k rpm you need 50+ psi). After that, you are just burning horsepower to make oil pressure.

Posted by: SLITS Jun 16 2009, 04:09 PM

The dry sump is setup for POSITIVE oiling under all conditions (assuming a correct installation). Dry sumps are used for a couple of reasons:

1.) Positive Oiling
2.) Reduction of oil volume in the case (or sump) to avoid parasitic drag of oil droplets in the rotating assembly (takes horsepower away)

Hell, Aerobatic capable planes use a dry sump system to fly upside down (at least for a few moments anyway).

Wet sump systems suffer from a couple of problems:

1.) Loss of oil pressure when the oil moves away from the oil pump pickup in hard cornering / hard acceleration or deacceleration.
2.) Parasitic drag on the rotating components of an engine robbing horsepower. That spinning crank assembly creates quite a storm over the lake of oil in the sump. Deep pans, specially modified pans with baffles, crank scrapers and windage trays were developed to overcome this horsepower robbing drag.

On a small 4 cylinder racing engine, I was once told that the dry sump system would add about 5 hp from the lack of the lake of oil ... maybe true, maybe not.

Ok, that's enough. Wanna know more ... visit a library.

Oh, an Accusump is a trade name ... the correct terminology is hydraulic accumulator ... the ones we used on the race cars were HAs from a Boeing 707 hydraulic system.

Posted by: brant Jun 16 2009, 05:10 PM

also...

you really don't want to add weight to the rear trunk of a race car
rules about weight apply to all weight... even oil weight.

low, forward on a 914, as little as possible.

I ran an accusump on the 4 race car but not the 6

Posted by: smj Jun 16 2009, 06:17 PM

Appreciate the clarifications on all sides. Maybe the Accusump-brand hydraulic accumulator will go into the 968 if I start logging serious track time on it.

Posted by: jt914-6 Jun 16 2009, 08:10 PM

I agree the six doesn't "need" it. The reason I have one in my six is to pre-pressure the oil system before starting the engine. I have oil pressure before I start it, so little or no bearing wear......

Posted by: 70Sixter Jun 17 2009, 02:10 PM

And for any Boxster guys out there, LN Engineering has adapter for Accusump. For our tankless "dry sumps."

Posted by: charliew Jun 19 2009, 04:24 PM

The next time someone tells you 50 psi is enough oil pressure at 7k go to nasioc or any forum that has high rpm motors and see what anyone that builds motors for a living thinks, 50psi might be fine on a 5k motor but thats all it will work on.

The idea is to have 10psi for every 1k at the hottest temp the motor will see and to run the thinnest oil that will hold that pressure.

Posted by: r_towle Jun 19 2009, 05:07 PM

SLITS cant just say one thing...he must finish...he couldnt stop himself....

Rich