Determining Proper Oil Volume with added Oil Cooler or Accusump.

We visited the Daytona Chump race a few weeks back and observed that many of the cars carry an Accusump. Some of them appeared to have the 3 quart model. We are considering one for our build, but I have a question and can't seem to find an answer.

We all know that too much oil in an engine is a bad thing. So how do you get the extra 3 quarts into an engine so that the Accusump can be filled? Along the same lines, if you add a large oil cooler and lines, how do you deternine the appropriate amount of oil for your engine. It would seem that the full mark on the dipstick does not take the additional volume of the oil cooler, lines, or Accusump into account. So how do you know when the engine has the right amount of oil "at rest."

Check the level while running. Good on the stick is good.

Fill to full at rest and then add what ever the added volume you have in the system. Note where this falls on the dipstick when at rest. Scribe dipstick if needed.

what I did, was fill as appropriate (before oil cooler) … start engine, run for a few sec … check dipstick … fill to full mark … wash, rinse, repeat until no need to add any

I think "3 quarts" is the entire volume of your Accusump, which ends up about half full because you're counting on the remaining 50% compressed air in the unit to push the oil back out. So, fill your car per its normal oil load, and add 1.5 quarts.

I'll bet a quarter that this is all explained on the Accusump site...

Another thing, oil coolers don't drain when the car is off so the level will still be accurate. As stated add a quart extra crank run 10sec, kill it and check, add as needed.

The accusump shouldn't drain when you shut the car off. Normal procedure is to shut the valve while the engine is running. Oil should then be at the normal dipstick level when the car is off. Same with a cooler, it should not drain.

When loading the accusump, put oil in it then pressurize the air.

For an oil cooler, it depends on how it's mounted.

If it's mounted low so that oil will stay in the cooler and lines when the engine isn't running, you just check the oil level as usual (and be sure to drain the cooler when doing oil changes). It'll take some extra to get it to the full level so there may be some guesswork involved the first time - after that, you'll have some idea of how much extra the system will take when filling from empty.

If it's mounted higher up so that oil will drain back into the pan when the engine isn't running, you'll need to lower the cooler so that oil stays in it, fill to the normal level, then install the cooler to its normal location and check and mark the new "full" level.

Filling to the factory full mark while running is a bad idea! What your oil level should be while running has nothing to do with the factory marks on the dipstick. Those tell you where the oil should come to when it all drains back into the pan. Also the amount of oil in the pan can vary with RPM. Comparing running levels before and after installing a cooler or accusump is a decent idea though.

An accusump is the same as a low-mounted oil cooler...oil stays in it when the engine isn't running.

chiodos wrote: Another thing, oil coolers don't drain when the car is off so the level will still be accurate. As stated add a quart extra crank run 10sec, kill it and check, add as needed.

I wouldn't say that, oil can drain with gravity if it drains to the pan. With a sandwich plate it should stay in the cooler.

Edit: Looks like a high-mounted cooler draining to a sandwich plate will still drain over a few days.

The set up I've seen has a manual shut off valve that you shut before you turn off the car. The Accusump site says rev the engine to keep the oil pressure up to fill the canister. However, if you spin and stall, the Accusump will dump the oil into the motor. I guess an extra 1.5 quarts won't hurt the motor when you start it up and the refil the Accusump.

I'd love to dry sump, but it is a Chumpcar

A 3 quart accusump holds 3 quarts of oil or at least real close to that when its under pressure. By pressure I mean full 60psi or so pressure. They are 4" in diameter and an 18" long 4" diameter cylinder holds 1 gallon. Before you shut off the engine, the valve closes either electronically or you do it manually. That leaves the 3 qts of oil in the cylinder. Before you start the engine, you open the valve and the 3 qts of oil pre oils the engine before you start it up. As the engine runs, the oil fills back into the cylinder and compresses the air. As the engine revs up and down, and as the oil pressure raises and lowers, the level of the oil in the cylinder goes up and down.

GameboyRMH wrote: For an oil cooler, it depends on how it's mounted. If it's mounted low so that oil will stay in the cooler and lines when the engine isn't running, you just check the oil level as usual (and be sure to drain the cooler when doing oil changes). It'll take some extra to get it to the full level so there may be some guesswork involved the first time - after that, you'll have some idea of how much extra the system will take when filling from empty. If it's mounted higher up so that oil will drain back into the pan when the engine isn't running, you'll need to lower the cooler so that oil stays in it, fill to the normal level, then install the cooler to its normal location and check and mark the new "full" level. Filling to the factory full mark while running is a bad idea! What your oil level should be while running has nothing to do with the factory marks on the dipstick. Those tell you where the oil should come to when it all drains back into the pan. Also the amount of oil in the pan can vary with RPM. Comparing running levels before and after installing a cooler or accusump is a decent idea though. An accusump is the same as a low-mounted oil cooler...oil stays in it when the engine isn't running.

the only car I have with an oil cooler is the TT/a-x car .. I change the oil often enough (at least twice a summer … sometimes 3 times) so the "dirty" oil in the cooler just mixes with the new oil when i change … the small amt. of "dirty" oil won't hurt the new oil at all … so I don't bother with taking loose the fittings … the more often that gets done, the more often the chance for a berkeley up

You could have capped the ends and submerge it and measure the water rise. Would have got you real close.

wvumtnbkr wrote: Check the level while running. Good on the stick is good.

Have you really ever tried to check the level with the engine running ?

In reply to iceracer:

Yes. In my owners manual it says to check with warm engine while idling.

In reply to GameboyRMH:

Disagree, I totally have pulled an oil cooler that is higher than the pan and was full of oil. Think about it, its all sealed so unless theres a leak to allow air in it will not drain. And your theory also would mean your motor dry starts every time cause it has to re prime.

wvumtnbkr wrote: In reply to iceracer: Yes. In my owners manual it says to check with warm engine while idling.

Please post a screenshot of the language in your owner's manual. You vehicle must be a unicorn, because I have never seen or heard of any four stroke engine where you check the oil level with the engine running.

maj75 wrote: I'd love to dry sump, but it is a Chumpcar

"EC" class.

maj75 wrote:

wvumtnbkr wrote: In reply to iceracer: Yes. In my owners manual it says to check with warm engine while idling.

Please post a screenshot of the language in your owner's manual. You vehicle must be a unicorn, because I have never seen or heard of any four stroke engine where you check the oil level with the engine running.

Air-cooled 911s require you to check the oil level with the car running and oil warmed up.

interesting … I actually tried that with my Honda once …once only .. the oil was spewing out of the dipstick tube … what a mess

Now we see the difference.

wbjones wrote: the only car I have with an oil cooler is the TT/a-x car .. I change the oil often enough (at least twice a summer … sometimes 3 times) so the "dirty" oil in the cooler just mixes with the new oil when i change … the small amt. of "dirty" oil won't hurt the new oil at all … so I don't bother with taking loose the fittings … the more often that gets done, the more often the chance for a berkeley up

Yeah, I don't bother to drain the cooler most of the time either. It doesn't hold all that much oil, just enough to dribble it everywhere and make a huge mess.

When I ran off road buggies, I don't think I ever had the oil drain back to the engine. Now you aren't talking much oil but both the coolers , ( we had duel coolers), lines and oil filter were all mounted higher than the sump. This was on an air cooled VW engine. I always pulled the stick prior to startup just to make sure it wasn't low( just a habit, check oil and fuel before every race :D). I don't ever remember it being higher than the high oil mark.

DWNSHFT wrote:

maj75 wrote:

wvumtnbkr wrote: In reply to iceracer: Yes. In my owners manual it says to check with warm engine while idling.

Please post a screenshot of the language in your owner's manual. You vehicle must be a unicorn, because I have never seen or heard of any four stroke engine where you check the oil level with the engine running.

Air-cooled 911s require you to check the oil level with the car running and oil warmed up.

Cause you are checking the oil level in the tank, not the oil in the pan. I'm sure dry sump car are the same. Plus he's got rotaries. Not a four stroke