Tell me about the Accusump. How did you hook it up? What size (& what engine)? Valve type?

I did a search & wasn't able to uncover to much info. There were some people who were going to use to prevent oil starvation. Did it work?

TIA

 

If you don't get responses here, try http://www.improvedtouring.com - I know it was discussed there not too long ago (and tends to come up every so often).

 

An Accusump oil accumulator is a cylinder with a floating piston in it. On one side is engine oil, connected to a pressure-side galley by a fat AN line. On the other side is a column of pressurized air. The system starts with nominal air pressure (something less than the oil operating pressure) pumped into this side through a Schrader valve, and the oil side effectively empty but bled so that there is no air in the line or cylinder.

When the engine is running, it pushes oil into the cylinder at the regular operating pressure of the engine. The air compresses until it is equalized. When the engine starves for oil, galley pressure drops and the air pressure shoves the oil from the cylinder into the engine.

The cylinder also has a simple on-off valve, which allows you to close it while the cylinder is pressurized. This way, you can open the valve before you start the engine and pre-oil the bearings. At least, so goes the theory. I know guys who swear by them and guys who swear AT them.

Kirk

EDIT - looking back, I don't think I actually answered your question. The one that I was closest to was about 4 quarts, on a VW Scirocco 1.6 Radial Sedan engine.



[Modified by Knestis, 11:14 PM 3/9/2003]

 

I've heard the same. Those that love them seem to all have cars with serious oiling problems (Porsche 944, certain VWs, amongst others). I haven't heard of a Honda that had oiling problems that couldn't be remedied with a revised oil pan.

 

http://forums.improvedtouring.com/it...ML/000424.html

still a bit undecided if its worth the cost or even functional.

 

This is where I come in... I run one in my '85 944. Not all guys that are on the track run them but others swear by them. After I did 2 laps at VIR last season with a broken oil pickup WITHOUT blowing my engine, I'll subscribe to them too. For the most part, 944 drivers use them because the cars are know for their starvation issues. This is the reason why I had mine. Turns out during a race last year my pil pickup snapped, starving the engine. The Accusump tried to normalize the pressure by sending more and more oil into the engine. I didn't notice a huge drop in pressure so I never knew until it had actually pumped so much oil that it started to come out of the dipstick tube... this lead to whire smoke and me pulling it, without blowing the engine. As far as starvation issues are concerned, I haven't heard of Hondas having enough of a problem to necessitate one.

 

The 'trying to keep up' thing is a good point. It would be useful to know what is going on...

I'm making this up as I go but it should be possible to put a pressure sender on the air side of the cylinder, calibrated to turn a BIG dash light on when it is out of oil (low air P) but off when it is full (high air P). Or tie it into your Pi dash

K

 

I do have a large warning light for oil pressure but your idea intrigues me. Because the Accusump was doing it's job, the light never came on so I really was unaware of the problem until the smoke.

 

Mine has a solenoid that automatically closes the valve after cutting the ignition to retain pressure. Turn key on, wait 10-20 seconds, start engine.

 

Thanks for the replies. Tyson, I did a search @ http://www.improvedtouring.com but somehow missed that thread. Funny thing is, I remember reading it...now.

Seems that most people don't think it is needed for a 'newer' engine like the D16Z6.

 

Knestis: my friend has Roe's Accusump-like device on his Viper. It has a large air pressure gauge on the end opposite the discharge valve. From what I have seen, this gauge appears to simply thread into a fitting on the fill head. It seems totally possible to add a T-fitting and a pressure sensitive switch (like AutoMeter's) to light an indicator when the cylinder pressure drops. In fact, now that you mentioned it, I think I will suggest this to my friend.
-Adam

 

That's exactly what I was picturing... One of the http://www.improvedtouring.com regulars has some Accusumps that I think he would be willing to part with, if someone wanted to post there and find out.
K

 

I like the idea of triggering a light with the accusump air pressure, it would be easy. I even considered a remote pressure gauge so I could monitor it from teh drivers seat.

Another added twist that I'm considering is the use of an RPM swith in conjunction with the electric valve (of course I had never heard of teh electric valves being a problem until reading the thread earlier in this post).

Anyhow, I still use my car around town, so I thought I might hook the valve up to a RPM switch. If I trigger it at 3000 RPM (easy to do), then I always have adequate oil pressure to keep the sump charged, and how often on a race course are you below 3000 rpm?

Scott

 

Anyone try hooking a light to your oil pressure sensor, this way U could see if the oil pressure ever drops in a hard turn from starvation. If the light never comes on then your ok and don't need the accusump. This might not even be a problem on most honda's, I would make sure you have starvation before trying to fix a non-existant problem. Anyway I have thought about setting up a light to indictate a drop in oil pressure it will porb. be one of my next projects.

 

AutoMeter offers a sender-activated switch box for such needs.
-Adam

 

Scott - let me know what you end up with for that setup. I want to do the same thing on my 'sump.

For the uninitiated -- if you leave an Accusump on all the time, at idle and low RPMs with low oil pressure, the sump leaves most of its contents in the oil pan. Sitting at idle with 2+ extra quarts in the oil pan is not a good thing for engine seals, etc. The sump is only needed at high RPM in high-g situations. Thus, an RPM switch and a cockpit indicator of operation would be perfect. A gauge indicating pressure is nice, but -- are you going to be looking at the gauge in the corners? It's not valuable. With an extra 2 or 3 quarts at pressure, you will only be in danger when doing skidpad testing.

I have a manual cockpit switch now and I usually leave it off for street/autocross. I *try* to remember to hit it on the warmup lap at the track, and I always use it to pre-oil the engine when strarting. That's almost worth the price of admission alone.


[Modified by whitney, 12:13 AM 3/11/2003]

 

I just ordered teh switch yesterday ($45 from summit). The one problem that it might have around town (or at an autocross) is that spinning the tires will prematurely activate the switch. Also, stop and go traffic will certainly put some wear and tear on things (so stick with a manual over ride).

One claim about the electric valve is that it controls the refil rate (that was a complaint in the IT forums thread, the electric valve fills too slow). Accusump says to use the electric to keep it from filling too fast (thus depriving the engine of oil).

My car loses pressure when I look at a right hand turn, but is fine on lefts (where the pickup is), so I will be charging the sump on all the straights and the lefts (not many), and discharging it on all the rights. If we ran tracks counter clockwise I would probably not have even bothered with the sump.

Another benefit, you can "short" the engine some oil (about a quart) when running an accusump, that is bad for thermal mass, but good for windage.

Scott

 

I have an 2 qt. manually operated Accusump on the race engine but have never used it because the car has yet to run. I got it for pre-oiling before firing and had planned to closing it off at high rpm/pressure shutting the engine down like on a cool off lap. I hadn't thought about it overfilling the sump at low pressure situations. Anything else a new user should keep in mind?

 

Maybe I'm missing something, but wouldn't measuring the pressure in the accumsump(oil or air side) and the engine oil pressure all be equal given that that oil pump is not pumping oil?