Engine oil accumulators

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dukeboy440

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So question. I’m wanting to run an accumulator on my engine, my question is how does this affect the oil capacity of the engine? For example, I know a “3 quart” oil accumulator actually only will contain 1.5-2.0 qts. So does this mean I need to add an additional 1.5-2 quarts to my engine, that way there’s the 7 quarts in the pan or am I over thinking this per normal?
 
there will only be 7qt in the pan if the engine is off, and you don't have a valve on the accumulator that you close prior to shutting down the engine.
 
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So question. I’m wanting to run an accumulator on my engine, my question is how does this affect the oil capacity of the engine? For example, I know a “3 quart” oil accumulator actually only will contain 1.5-2.0 qts. So does this mean I need to add an additional 1.5-2 quarts to my engine, that way there’s the 7 quarts in the pan or am I over thinking this per normal?

Yes you need to add more oil to compensate for what is stored in the cylinder. With the cylinder full your dipstick should read normal. I use a cable operated manual shutoff valve on mine.
 
I am about to install my accumulator, so at this point I have no first hand working knowledge. Here is the understanding I have though. The volume of oil your accumulator holds must be accounted for in addition to your oil pan capacity. In the case of mine, the adapter goes between the oil filter and block. This requires pulling the distributor at each oil change and driving the oil pump with a drill to fill the accumulator. This is done to prevent oil starvation for the period of time it would take to fill the accumulator on startup. I will be running my accumulator valves off of a pressure switch.
 
I am about to install my accumulator, so at this point I have no first hand working knowledge. Here is the understanding I have though. The volume of oil your accumulator holds must be accounted for in addition to your oil pan capacity. In the case of mine, the adapter goes between the oil filter and block. This requires pulling the distributor at each oil change and driving the oil pump with a drill to fill the accumulator. This is done to prevent oil starvation for the period of time it would take to fill the accumulator on startup. I will be running my accumulator valves off of a pressure switch.
Sounds like a hassle at oil change time. Why not put a manual valve in it sized appropriately (the accumulators I have bought in the past came with a valve screwed directly into the accumulator). Close the valve prior to start up after the oil change. After the motor has started and run a bit crack the valve a little and when the accumulator is full open the valve full open. How are you plumbing a pressure switch in the system?
 
I guess this is for eliminating dry start conditions? IMO, I think the correct level is just something you're gonna have to experiment with. I would maybe try half the accumulator capacity and go "from there".
 
I guess this is for eliminating dry start conditions? IMO, I think the correct level is just something you're gonna have to experiment with. I would maybe try half the accumulator capacity and go "from there".
Dry starts yes but also because I plan to hot lap this thing in road courses. Plus It’s more of a piece of mind.
 
I guess this is for eliminating dry start conditions? IMO, I think the correct level is just something you're gonna have to experiment with. I would maybe try half the accumulator capacity and go "from there".
I'm trying to figure out in my head how that would work. Key on and no oil pressure would open the valve? So when motor starts and you have oil pressure the valve closes? I guessing that would need to be a switch that is set to an oil pressure that is higher than idle. Or I guess you could always rev the motor to charge the accumulator before you shut it off. I have only used accumulators for circle track racing back in the claimer days as a way to use a stock oil pan in a circle track car. Not for dry starts although you could do that also. We set the level like previously mentioned by raising the rpm a little above idle to get good oil pressure on a hot engine then closing the valve. Shut the motor off and set the oil level to normal spot on the dipstick, site plug or however you're setting the oil level. The accumulators that I had used air pressure on the back side of a floating piston as a "air spring". Adjusting the preload pressure had a small affect on how much oil discharged and how much it would hold. I think we ran between 9 and 14 psi. Also to get all the oil out of the accumulator during an oil change you would have to put a high charge of air in it to force the piston all the way to the end of the cylinder. I also had one that had to be mounted vertical (to keep air above the oil. It didn't use a piston only the air above the oil to push the oil back out when pressure dropped. I think it only held about a quart.
 
Dry starts yes but also because I plan to hot lap this thing in road courses. Plus It’s more of a piece of mind.

Are you putting a Milodon road race pan on it?

For most use that is enough.
 
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