Addressing N5x oiling and spun rod bearings (Accusump installed)

AndyW

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Jul 17, 2019
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Laps on Friday's HPDE were mostly in the wet and were at Pacific Raceways vice the Ridge, so not an apples to apples comparison, but I have no oil pressure drop below 40# all day. Accusump works. Really gotta figure out how to balance the amount of oil in the sump vs accusump. I turned off the EPC valve on the track so it filled with oil to about 80#. I parked the car Saturday morning and when I started it, it gave me the "1qt low" warning. I added another half quart but the level didn't seem to move. I then enabled the EPC so all the oil fed to the system and level is now at the high mark. Seems weird. It should be reading over max with over 2 qts total that i have added extra. Will have to keep an eye on it. Not sure how far it can be safely overfilled on level ground.

 

AndyW

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Jul 17, 2019
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So I had an epiphany...I already knew how to figure out the volume of oil in the Accusump from my engineering knowledge...Boyles Law. Which I think can be reasonably applied.

Given a constant temperature and an ideal gas (neither of which is strictly true in our case, but I think it's close enough), Pressure and Volume at two states are directly related.

In equation form:

P1*V1 = P2*V2

If state 1 is 10# on the air side and zero oil, the air side has 10# of 3 qts of air.

At idle, P2 is approximately 40#. We then just solve for V2, which gives 3/4 qt, which is the volume on the air side, therefore the oil volume is 3 - 3/4 = 2 1/4 qts.

At 80#, V2 is 3/8 qt, therefore volume of oil is 2 5/8 qts. So the variance of oil volume from 40# to 80# is less than half a quart.

So my concern for overfilling the sump is pretty much gone. Even if I accidentally left the EPC on coming off the track, then turned off the car, the max of 2 5/8 qts added to the sump shouldn't be too harmful, especially since the Accusump would rapidly accept the 2 1/4 qts on refill at 40# idle the next time you started the car.
 

derekgates

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AndyW

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Damn that's detailed.


This is big brain time.



Why not on SpoolStreet? :(

Thx!

The light thing was really driven by laziness. Didn't want to mess with routing into the dash.

1addicts is kinda my "home"...and I did post the link here ...😁
 

derekgates

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Thx!

The light thing was really driven by laziness. Didn't want to mess with routing into the dash.

1addicts is kinda my "home"...and I did post the link here ...😁

Ha, well the light is pretty cool cause you are already looking down the hood. Reduces amount of eye movement you need to see indicator.



I am joking about not having it here, but I appreciate the community that @doublespaces has created that also doubles as an archive.
 

screaminfast

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Quick question about the accusump plumbing... What's the purpose of the electronic pressure switch vs just an electronic solenoid valve? I'd be putting on my N54 for pre-oiling mostly, but for autox/track days as well. Seems as though many people just use the manual valve ones in their cars (not specifically our platform). Thanks!
 

AndyW

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Jul 17, 2019
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Quick question about the accusump plumbing... What's the purpose of the electronic pressure switch vs just an electronic solenoid valve? I'd be putting on my N54 for pre-oiling mostly, but for autox/track days as well. Seems as though many people just use the manual valve ones in their cars (not specifically our platform). Thanks!

Canton has good descriptions of the various ways to implement the Accusump.
In short, The solenoid control allows it to send oil into the galley when pressure falls below the setpoint and allows it to return when above. It is used as a sump oil starvation mitigator.
 

doublespaces

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Thx!

The light thing was really driven by laziness. Didn't want to mess with routing into the dash.

1addicts is kinda my "home"...and I did post the link here ...😁

There are benefits to posting here, for one you'll probably never find a guide with busted hot linked images. Many people remember the Photobucket debacle. Tons of guides on e90post and bimmerpost I'm general are permanently broken because the images are gone.

That doesn't happen here because hot linked images are automatically saved as attachments to the post.
 

AndyW

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Jul 17, 2019
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There are benefits to posting here, for one you'll probably never find a guide with busted hot linked images. Many people remember the Photobucket debacle. Tons of guides on e90post and bimmerpost I'm general are permanently broken because the images are gone.

That doesn't happen here because hot linked images are automatically saved as attachments to the post.

Don't get me wrong...this place is awesome. And i host my pics on my own space online, partly for the reasons you mentioned.
 

screaminfast

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Feb 18, 2017
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Canton has good descriptions of the various ways to implement the Accusump.
In short, The solenoid control allows it to send oil into the galley when pressure falls below the setpoint and allows it to return when above. It is used as a sump oil starvation mitigator.

At this point, I’ve read every pdf and watched every video and I’m still slightly confused.

Let’s say I do a 1qt accumulator with an electric valve. I open it before i start motor for preoiling. With it open all the time wouldn’t it maintain steady state of extra “backup oil”? Then before shutting off motor, you close the valve so it has some pressure built up for next preoiling.

Does that make sense to anyone else? What’s the advantage of the pressure activated solenoid?
 

AndyW

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Jul 17, 2019
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2012 BMW 135i
At this point, I’ve read every pdf and watched every video and I’m still slightly confused.

Let’s say I do a 1qt accumulator with an electric valve. I open it before i start motor for preoiling. With it open all the time wouldn’t it maintain steady state of extra “backup oil”? Then before shutting off motor, you close the valve so it has some pressure built up for next preoiling.

Does that make sense to anyone else? What’s the advantage of the pressure activated solenoid?

 

screaminfast

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Feb 18, 2017
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Ok that definitely makes a little more sense now. The question I have to ask myself is am I using this solely to provide more volume and preoiling or do I want to spend the $2-300 for the EPC.
 

AndyW

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Jul 17, 2019
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Ok that definitely makes a little more sense now. The question I have to ask myself is am I using this solely to provide more volume and preoiling or do I want to spend the $2-300 for the EPC.

Exactly. For me, the EPC is a precision tool to control when oil is supplied for an oil starvation scenario. I want to maximize the time oil can be delivered in this scenario. Side benefit is preoiling.
 

ShaunX5M

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Nov 6, 2020
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The only drawback? I've hit a DME safety roadblock. The DME is seeing the higher then expected oil pressure prior to starting and throws a CEL. The oil pressure relief valve is then put into a fail-safe mode and the oil pump delivers 100% of its volume to engine (N55 has electronically controlled oil pressure). I don't think it's OK though to daily drive with 110psi oil pressure. This is something I ask the community to help figure out in order to make this feature of the Accusump usable.

Thanks for the awesome thread and information!

I'm wondering if you (or anyone else) were able to disable this DME fault/CEL on start for higher pre-start oil pressure?

I'm buying an e70 X5 M with the S63 engine and want to pre-oil to try and keep the rod/main bearings going. I'm not sure if the DME in the X5 M has the same protection, but it likely would. I want to fully automate the pre-oiling so if someone else drives the car I don't need to try and teach them a magic pre-start handshake :D

Cheers!
Shaun
 

Bnks334

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Dec 1, 2016
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Thanks for the awesome thread and information!

I'm wondering if you (or anyone else) were able to disable this DME fault/CEL on start for higher pre-start oil pressure?

I'm buying an e70 X5 M with the S63 engine and want to pre-oil to try and keep the rod/main bearings going. I'm not sure if the DME in the X5 M has the same protection, but it likely would. I want to fully automate the pre-oiling so if someone else drives the car I don't need to try and teach them a magic pre-start handshake :D

Cheers!
Shaun

you can still prime the engine... just gotta crank it quick after flipping the switch! if you let it build 60psi before cranking then yeah it throws the code, but, if you flip the switch and then crank instantly you're good and still get the benefit of the accusump building a little pressure before you can get the car started.

you would need to wire into a fuse that comes alive with the ignition.
 
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marv85

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Jun 14, 2018
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@Bnks334 sorry if this was already covered, but how does accusump differentiate between a g force induced pressure drop versus a pressure due to falling rpms ? I have an N54

How’s your engine reliability at the track since installing accusump? I’m starting to track my 335i and prefer to get ahead of oil starvation. I’m not at the performance level where it’s a problem (based on my logs), but I have big plans for my next track day, especially braking wise. This last time my brakes weren’t up for it, so I wasn’t slamming them, but I worry next time around with upgraded brakes and newer tires..
 

Bnks334

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Dec 1, 2016
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@Bnks334 sorry if this was already covered, but how does accusump differentiate between a g force induced pressure drop versus a pressure due to falling rpms ? I have an N54

How’s your engine reliability at the track since installing accusump? I’m starting to track my 335i and prefer to get ahead of oil starvation. I’m not at the performance level where it’s a problem (based on my logs), but I have big plans for my next track day, especially braking wise. This last time my brakes weren’t up for it, so I wasn’t slamming them, but I worry next time around with upgraded brakes and newer tires..

Maybe watch the video from Moroso on youtube about how these things work. I covered how the electric valve can be controlled by a switch to prevent it from dumping at idle where the pressure is very low. The manual valve is always open and find equilibrium with whatever engine pressure is.

 
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