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-   -   Accusump - pros & cons (https://classracer.com/classforum/showthread.php?t=86480)

J.R. Haddad 01-06-2024 10:17 AM

Re: Accusump - pros & cons
 
1320, I don't know if I'm trying to band aid anything, as much as trying
to be proactive. In Stock Eliminator, from time to time, you might run
less oil than normal. The reasons can vary, from trying to move up on
the qualifying sheet to gain an early bye run, to a heads up run where
you need a little more than you presently have. In these events, top
end braking can send the oil pressure down lower than anybody
should be happy about. I think I like the piece of mind of knowing
there is additional oil available if needed. Thanks for asking.

J.R.

1320racer 01-06-2024 12:44 PM

Re: Accusump - pros & cons
 
I'm well aware of stockers running even less oil than their normal 1 quart low. I'm also well aware of losing oil pressure when driving the stripe and I'm also well aware of the thousands of racers including stockers that do not, have never, run an accusump, myself included.

JGrossijr 01-06-2024 01:30 PM

Re: Accusump - pros & cons
 
One consideration regarding accumulator volume selection is that capacity does not necessarily, and in my experience never does, equal actual working volume. Engine oil pressure, valving, and accumulator air pressure will determine how much oil is actually held in the accumulator.
  • The higher the oil pressure the more oil that can be stored in the accumulator up to capacity
  • The more air in the accumulator the less oil that will be stored in the accumulator
  • In simple open or closed valving (mechanical or electric) the oil volume in the accumulator, and in the engine sump, will vary.
In my opinion Mike Mans nailed the best reason for an accumulator. You end with the ability to pre-lube the engine on every start-up, whether its been 5 minutes or 5 months. This is particularly important on an engine like an LS with a front-mount above sump oil pump.
Secondly the accumulator acts as an insurance should the oil pressure drop for whatever reason. This can be particularly important in those circumstances where you find yourself draining oil to a minimum level for that go-fast run.

Don't simply plumb an accumulator into your oil system and assume it is holding the advertised capacity. Doing so will like result in more oil than you want in the sump, and more windage. After you install the system run the engine up to maximum oil pressure, close the valve, and shut the engine off. Disconnect the oil line and discharge the accumulator to determine what the maximum amount of storage actually is in your application. Try this with different amounts of air in the accumulator and determine what the ideal amount of air pressure is for your application. This will help you determine how much extra oil to add to your system. Keep in mind this volume will change as oil pressure changes in a simple open/closed valving, therefore engine oil level will vary proportionally to oil pressure.

This is where the Canton EPC valve
really shines. When the valve is closed it continues to fill and only discharges when pressure falls below a preset point. The preset point can be controlled with a mechanical pressure switch as supplied, or from a programmable switch output from your ECU. In this scenario there won't any oil being pushed into the engine until pressure drops below your pre-set, and the maximum amount of oil will be stored in the accumulator at all times above the preset. The preset point is generally just below idle pressure. In this case as the engine goes through higher pressures at higher rpm you push more oil into the accumulator. After a burnout, or any other significant rise in rpm the accumulator will be as full as it's going to get, and it will hold that volume until pressure falls below the preset. Should a condition arise where oil pressure drops below the preset the accumulator is as full as it can be with the most pressure possible, so response is quick with good duration. You would be amazed the differences in discharge at different holding pressures.

FWIW - The most oil I have been able to get into a 3 qt. Moroso accumulator at 90 psi was 2.5 qts.

1320racer 01-06-2024 01:40 PM

Re: Accusump - pros & cons
 
FWIW, I prelube my engines prior to the 1st start of the race day by cranking them until I have at least 30 psi oil pressure, after that I ain't worried and drive it like I stole it!:D

Steve Grady 01-06-2024 02:32 PM

Re: Accusump - pros & cons
 
Quote:

Originally Posted by JGrossijr (Post 691182)
One consideration regarding accumulator volume selection is that capacity does not necessarily, and in my experience never does, equal actual working volume. Engine oil pressure, valving, and accumulator air pressure will determine how much oil is actually held in the accumulator.
  • The higher the oil pressure the more oil that can be stored in the accumulator up to capacity
  • The more air in the accumulator the less oil that will be stored in the accumulator
  • In simple open or closed valving (mechanical or electric) the oil volume in the accumulator, and in the engine sump, will vary.
In my opinion Mike Mans nailed the best reason for an accumulator. You end with the ability to pre-lube the engine on every start-up, whether its been 5 minutes or 5 months. This is particularly important on an engine like an LS with a front-mount above sump oil pump.
Secondly the accumulator acts as an insurance should the oil pressure drop for whatever reason. This can be particularly important in those circumstances where you find yourself draining oil to a minimum level for that go-fast run.

Don't simply plumb an accumulator into your oil system and assume it is holding the advertised capacity. Doing so will like result in more oil than you want in the sump, and more windage. After you install the system run the engine up to maximum oil pressure, close the valve, and shut the engine off. Disconnect the oil line and discharge the accumulator to determine what the maximum amount of storage actually is in your application. Try this with different amounts of air in the accumulator and determine what the ideal amount of air pressure is for your application. This will help you determine how much extra oil to add to your system. Keep in mind this volume will change as oil pressure changes in a simple open/closed valving, therefore engine oil level will vary proportionally to oil pressure.

This is where the Canton EPC valve
really shines. When the valve is closed it continues to fill and only discharges when pressure falls below a preset point. The preset point can be controlled with a mechanical pressure switch as supplied, or from a programmable switch output from your ECU. In this scenario there won't any oil being pushed into the engine until pressure drops below your pre-set, and the maximum amount of oil will be stored in the accumulator at all times above the preset. The preset point is generally just below idle pressure. In this case as the engine goes through higher pressures at higher rpm you push more oil into the accumulator. After a burnout, or any other significant rise in rpm the accumulator will be as full as it's going to get, and it will hold that volume until pressure falls below the preset. Should a condition arise where oil pressure drops below the preset the accumulator is as full as it can be with the most pressure possible, so response is quick with good duration. You would be amazed the differences in discharge at different holding pressures.

FWIW - The most oil I have been able to get into a 3 qt. Moroso accumulator at 90 psi was 2.5 qts.


Thank you for sharing your Real World experience.

CMcAllister 01-06-2024 04:31 PM

Re: Accusump - pros & cons
 
Ran a Moroso forever. Wouldn't have a car without it. And the Moroso electric valve, which acts as a diode and allows the Accusump to recharge when turned off.

I had it on a dedicated switch. Turn on before first start of the day or weekend to pre oil the engine, turn off, then start it. Turn on going into the water, turn off after making the turn off. Otherwise, it is being charged for the next use whenever the engine is running.

When on, pressurized oil remains pushed into the can by engine oil pressure and will be able to catch a low pressure issue should a pump suck air for any reason.

Also, fill and charge when doing a fresh engine to preoil just before first start.

Setting the initial charge pressure on top of the piston at 6 PSI will allow the most oil to be pushed into the can while ensuring it will push the piston all the way to the bottom of the can. Higher pressures reduce the amount of oil the pump will push into the can.

No experience with the Canton valve, but it sounds like an easy way to maintain a consistent oil level in the pan until a low pressure issue arises.

J.R. Haddad 01-06-2024 06:02 PM

Re: Accusump - pros & cons
 
Mr. Grossi, Thank You for taking the time to break things down the way
that have. Very helpful, and it is making me happy about my decision.
1320, I don't know many that don't crank away at our engines after they
have been sitting for 2, 3 or more weeks. Been doing it a long time myself.
But you see, I would rather pre-lube the engine, and then I can crank it
until my heart is content, knowing there is oil in all the right places. As for
the 1000's of Stock Racers that have drained oil and don't have an
Accusump, add me to that list. However, I am not so set in my ways, or
have such a high opinion of myself, that I can keep my mind open to
finding potential ways to improve my program. I would like to have the
strength of conviction that there is only my way, and no other way, like
some have, but I would soon tire of being wrong, publicly, that many times.

J.R.

1320racer 01-06-2024 10:54 PM

Re: Accusump - pros & cons
 
You do you, I'll do me. My programs works very well without an accusump and produces the results we seek...WINS, Big $ Gambler race checks, Wallys and Championships.

Jason Shepard 01-07-2024 02:01 AM

Re: Accusump - pros & cons
 
Quote:

Originally Posted by 1320racer (Post 691212)
You do you, I'll do me. My programs works very well without an accusump and produces the results we seek...WINS, Big $ Gambler race checks, Wallys and Championships.

I believe it was grade school where I learned the saying "if you cant say anything nice, dont say anything at all"

Did you ever learn that?

1320racer 01-07-2024 08:47 AM

Re: Accusump - pros & cons
 
What part of he TRUTH and the FGACTS don't you like?:p


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