I was just wandering what you guys thought about using an Accusump to alleviate oil pressure in the LD9. Im aware, that its more about flow than pressure, but since you add 3 quarts of oil into this additional reservoir I would assume it serves both purposes and can get rid of the common bearing failures.
Accusumps have two purposes:
Pre oiling at cold start
When there is a loss of oil pressure (surges, heavy breaking and turning) it provides pressurized oil.
Would this work on the LD9 if we were to install it using the sandwich bracket between the oil filter? Would it prevent the bearing failures?
Heres a little technical about it:
Accusump Technical Information
The Accusump, the original automotive oil accumulator, is designed to provide the engine with oil pressure before the starter is even engaged. An Accusump is a cylinder shaped aluminum storage container that acts as a reservoir of pressurized oil, to be released when there is a drop in the oil pressure.
The Accusump is connected to the pressure side of an engine's oiling system and is charged by the engines own oil pump. Its simple, efficient design revolves around a hydraulic piston separating an air pre-charge side and the oil reservoir side. On the oil side of the Accusump, it has an outlet that goes into the engine's oiling system, controlled by a valve. On the air side, it's equipped with a pressure gauge and a Schrader air pre-load valve.
Normal Operating Conditions
Accusump
Discharging When Pickup Is Uncovered
Accusump
The Accusump provides that extra margin of protection that you need against engine damage caused by loss of oil pressure. Racing and high performance street engines by nature are put under a lot of stress by the high G-load situations they are commonly placed in. As oil in your pan sloshes about, your oil pump pickup can become uncovered, which causes a loss of oil pressure and sets the stage for severe engine damage. The Accusump provides oil during these times reducing the potential for damage.
I actually had this recommended to me over a year ago... not this exact product but the entire concept of it - an oil "capacitor" that would discharge when needed, as stated above...
I don't see it hurting.... the question is will the gains be able to really help out with the issues the LD9 suffers from in stock form?
-Chris-
-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
The way the backside is presurized is a little vague at best....a little more info on how it works would help alot. Without some stored energy I dont know how you would have pressure before you turn the key since the oil pump is crank driven.
It seems like it uses air pressure to pressurize the cannister. Sorta like a cap as soon as it's discharged it's recharged and left waiting.
-Chris-
-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
^Sure but recharged how....you would need a compressor and tank or someother source of stored energy. That would kinda suck, not to mention take up more room and add weight. Good idea, but has some pretty bad downsides.
well couldnt u just get a small pump mounted to like ur firewall ....or do a battery to trunk swap and put it where the battery was.....
you scratch my ride IMA EAT YO CHILDREN
or u could just do an airride setup with a line goin to the Accusump
you scratch my ride IMA EAT YO CHILDREN
I did a little research on it. There is no stored tank needed to pressurize the system. What scares me is that it uses the pressure from our oil pumps. Basically, its a cylinder with a hydraulic mechanism (piston in the middle, seprating to parts in a cylinder). Oil sprays in from one side, pushing the piston which compresses the air on the other side of the piston. How it works? once it senses a drop in pressure or is turned on for a cold start (by the ignition), it shoots stored oil through a line that goes to your oil filter (adaptor plate sandwiched btw). Im actually quite surprised none of us have used it, especially for the track, its a must.
Nonetheless, the exact system (Accusump) which runs about 200 US comes stock on this badboy...for 200 bucks, im gonna grab it in April and see what its all about.
How the hell would it stay pressurized? I can see how while running you could use your oil pump to compress the air in the tank and then use it as a oil capacitor...yes that would work but how the hell would it keep pressure after the vehicle is shut down? Unless there is an electric check valve that runs off a relay tied into your ignition switch theres no way it will hold pressure over any length of time without dumping the oil out the second your oil pump stops pushing against it.
Edited 1 time(s). Last edited Tuesday, March 06, 2007 4:56 PM
I've never, ever, ever heard of this product. I've never seen any mention of it here, I've never read about it in any car magazine, nor heard anyone ever make mention of it in person. I don't see how it's such a "must" if nobody has heard of it before. Mayhaps it's like one of those atom aligners that gives you an extra 20mpg
14.330 @ 96.37mph
no actaully its a quite common product, i've heard very good things about it.
just recently i was trying to think of a way to solve the oil pressure problem with out the 2.3 swap...i was going to look into a new pump, and such
but now that you've brought this up, it could be a good alternative.. besides the cold start up thing, that joshua is worried about.. seems like this could work for the oil pressure drop that supposely happens at 5500rpms..(i say supposely because i have yet to see it with my own eyes, since i don't have a oil pressure gauge)
Once it fills up it has a valve that closes automatically when it sees lower pressures and instantly throws in oil. Heres an excerpt from their site:
"The Eletric Pressure Control valve allows the Accusump to quickly charge with oil when the engine's oil pressure is above a predetermined level and discharge when the engine's oil pressure drops below that level"
Ryan, in terms of the cold start, the Accusump automatically fills itself up as you drive, it charges itself up (compresses the piston which compresses the oil on the other side of it) when the oil pressure is above a level set by you. Obviously, the first time you install it, you would have to fill it with about 50psi of air. In terms of cold starts, as soon as you turn the ignition on, im assuming it releases the pressured oil, and refills again...
And Bill...its funny because I was reading a car mag and found this. The new Lotus Espirit Type S comes stock with it, and if that car came stock with it (and Porche's come with dry sumps), I dont see any problem with it at all. It can even be mounted straight into the oil gallerys. Im going for it and Accusump has been around since the 70s.
heres a pic of it:
let me know how well it works, and if you notice any difference in higher RPM oil pressure
So if it does have an electric check valve then it will work for a "wet start" setup but will do nothing to maintain long term pressure drop like you will see at high rpm, it will only help for small length of time. It will do nothing to solve a pumps short comings.
Joshua, how much time do you think you spend at 5500rpm? Once it senses a loss, depending on the valve you choose it has a rapid refill rate. Do we always lose pressure at 5500rpm anyway?
Does anyone know what the oil pressure is on an LD9 at 5000 rpm and above? You can actually purchase valves according to how much pressure is lose for i.e. you can make it come on at 20-25psi.
Yes, but how big do you think the reservoir would need to be to keep the pressure up and for how long? It all depends on volume required.....
Dont get me wrong, its a great idea for cold starts, and thats where the biggest advantage is gained. As far as a oil pump band aid for high rpm, it might work, but i cringe at the thought. I mean when the thing is filling while at lower rpm during a race do you really think this thing wont effect oiling? You'll be robbing your motor of oil while this thing is filling, its a horrible oil pump band aid. I really dont think its worth the risk.
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You'll be robbing your motor of oil while this thing is filling, its a horrible oil pump band aid. I really dont think its worth the risk.
Joshua, thats why it needs three extra liters of oil. If anything your robbing oil pressure, since that pressure needs to compress the piston inside the accusump. Thats the only draw back, but there is plenty of pressure at lower rpms anyway. Looking at how cheap this system is, id say its worth it. I want to buy it, to test it. I just emailed them to ask how fast it actually refills onces it opens.
To pressurize the back side it must add oil to the front....this addition of oil can only come from one place.....the motor must go without that oil. The spped at which it fills depends on your oil pump, the flow rate vs. pressure of the pump actually. Its a bad idea to put this design on a weak oiling system......bad.
^You can't rob pressure without robbing flow rate, oil will flow to the path of least resistance, when the bottle fills it must then be the path of least resistance. Meanwhile the other parts of your motor will be going without some oil while this thing fills. Try it out, let us know how it works, but I'd suggest dfoing a 2.3l pump swap first.
Money would be better spent on baffling the oil pan to avoid having a dry pickup.
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You can't rob pressure without robbing flow rate,
Joshua, it seems to me like you are under the impression that the system only uses the existing oil (4.5 liters). Depending on how big the accusump is, you actually need to add extra oil into your motor, the first time you start it up, that oil will flow throw the path of least resistance and into the accusump (stored there until it is needed). Then you fill your oil up to the full mark. This is only done the first time you install it. So basically you have about 7 liters of oil! My worry was that I actually thought it shoots 3 liters of oil everytime it was triggered. And adding 3 extra liters to a motor that only holds 4.5 would kill it. I emailed them and this is what they told me:
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Sam the accusump only pushes in what is needed to get the pressure to rise back up to were it should be, the only time you will have an entire 3 qts extra in the sump (or oil pan) would be when you pre lube the engine, other than that the accusump only releases what is needed to get the pressure to rise, we also make a 2 and 1 quart version.
