Addressing N5x oiling and spun rod bearings (Accusump installed)

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shushikiary

Corporal
Jun 4, 2018
141
I'm considering adding one of these to my car, but not running a pressure valve, just an electric on/off valve that I'd have the switch for and then wire it to the ignition.

My question is though, I saw in another thread the OP posted that he had issues with getting the oil level right, so what were those issues? Adding 3 quarts like they said didn't go well?
 

Bnks334

Sergeant
Dec 1, 2016
388
New York
That's awesome I wish wasnt such a bitch to drop oil pan
Getting the oil pan completely out is a bitch. lowering it to change the gasket is easy but to actually get the pan to clear the sub-frame requires completely dropping the sub-frame and jacking the engine up. If you're on a lift it's not too bad but working on your back is horrible. I'd rather pull the entire engine than drop the subframe on jack stands. At least removing all the front end is easy work and you're on your feet.
 

KevinC39

Corporal
Jun 27, 2017
188
I just did this when putting on my turbo kit. It's not too bad to get it out when the subframe is already dropped even on jack stands but it's certainly not fun. It would definitely be annoying to do if I wasn't already in there for the turbo.
 

Bnks334

Sergeant
Dec 1, 2016
388
New York
I'm considering adding one of these to my car, but not running a pressure valve, just an electric on/off valve that I'd have the switch for and then wire it to the ignition.

My question is though, I saw in another thread the OP posted that he had issues with getting the oil level right, so what were those issues? Adding 3 quarts like they said didn't go well?
Me? I have not had too many issues with oil level. There was a bit of a learning curve to do oil changes and what not, but, things have been fine. Just gotta be aware of how charged up the accumulator is. It holds about 3qts as advertised.

Canton has a lot of info on the manual vs electronic valve: http://blog.cantonracingproducts.com/blog/importance-of-accusump-valve-selection-how-to-choose

There are pros and cons to each.
 

shushikiary

Corporal
Jun 4, 2018
141
I would have figured that you'd just discharge the accumulator for the oil change so you change its oil as well, is that not what you do?

Read that blog post, and based on the N54 oil pressures posted on the internet (22 psi hot idle, and 65-70 psi under load) you'd want to pick the valve you did and then turn it off at idle. I had called them about exactly this and described my situation, where I wasn't tracking, but especially under hard braking I see some issues. Because I wanted to use it on the street all the time, and not just on the track, flipping the switch on and off at idle all the time would be very painful, so he suggested just using the electric switch connected to ignition.
 

Asbjorn

Sergeant
Mar 10, 2018
455
Europe, based in China
I would have figured that you'd just discharge the accumulator for the oil change so you change its oil as well, is that not what you do?

Read that blog post, and based on the N54 oil pressures posted on the internet (22 psi hot idle, and 65-70 psi under load) you'd want to pick the valve you did and then turn it off at idle. I had called them about exactly this and described my situation, where I wasn't tracking, but especially under hard braking I see some issues. Because I wanted to use it on the street all the time, and not just on the track, flipping the switch on and off at idle all the time would be very painful, so he suggested just using the electric switch connected to ignition.
I see much much higher oil pressure. Where did you read that?
 

Bnks334

Sergeant
Dec 1, 2016
388
New York
I would have figured that you'd just discharge the accumulator for the oil change so you change its oil as well, is that not what you do?

Read that blog post, and based on the N54 oil pressures posted on the internet (22 psi hot idle, and 65-70 psi under load) you'd want to pick the valve you did and then turn it off at idle. I had called them about exactly this and described my situation, where I wasn't tracking, but especially under hard braking I see some issues. Because I wanted to use it on the street all the time, and not just on the track, flipping the switch on and off at idle all the time would be very painful, so he suggested just using the electric switch connected to ignition.
Yes, discharging it and then putting back in 10.5qts works fine. Then I top off as needed. I usually don't bother though since I don't daily the car anymore and change the oil every few months regardless of mileage.

I had also read N54 oil pressure was in that range which is why I had questioned the placement of the pressure sensor asbjorn installed. You're correct about the electronic valve. If you wire it to the ignition then it will be dumping every time you sit at a light. The problem I had with that is it will burn out the electronic solenoid quickly since it's constantly firing. I would not use the electronic valve without a switch, or, you can use the really low psi valve. Maybe Canton updated the electronic solenoid so it is more robust? it may be a non-issue now. Manual valve would be dumping all the time too but it's not an issue since there is no electronic solenoid to burn out.

Being overfilled would be a concern as well. whipping air into the oil is no good. That's why I went with the switch. Knowing N55 oil pressure is ~40psi at idle I turn the switch off preventing the accusump from firing and overfilling the pan. I don't use it on the street so I have no issue with this. I didn't want to use the low psi valve since in Motorsports applications I am really never below 3,000rpm/60psi to warrant using a lower psi valve.
 

shushikiary

Corporal
Jun 4, 2018
141
Asbjorn, reference this thread: https://www.e90post.com/forums/showthread.php?t=581081 He's measuring pressure at the same location that the stock oil pressure switch is installed (that's what the LeatherZ setup places its sending unit), aka just after the oil filter.

From the install instructions on the electric (non pressure sensing) setups (aka part 24-270x) its designed to work as always on when the ignition is on. So I wouldn't have any worry about wearing out the valve because its always on, or else they have a very poor design. Seeing too that the valve is the same for all the applications, they just use a pressure activated switch to control the valve in the other units, I doubt it always being on is an issue.

Doing some basic math here... the moroso accumulator (which is the one I have, 3 qt, same as Bnks) is 167 cubic inches inside volume (I measured the ID of the cyl, depth at full, depth at empty, and calculated the volume). I'll fill with nitrogen so the temp effects its operation less, but you're supposed to fill it to 6 psi with no oil in it.

Thus with PV=NRT we have 0.0460982 moles of air at 72 deg F. If we change the pressure to 22 psi (what it will be at idle as the piston moves to make the pressure equal on both sides), the new volume that same mass of air takes up is: 45.5454 cubic inches. Which means the accumulator is still holding 167 - 45.5 = 121.5 cubic inches of oil. Which is 2.1 quarts.

So that means it only added 0.8 quarts to the system at idle oil pressure levels (because 167 cubic inches is only 2.9 quarts).

So I'm not too worried about that.

If you're looking at that number and going "wow that doesn't add a ton of oil until you're really low on oil pressure) that's exactly right, and that's exactly why they Accusump makes a "high pressure" version that is 6 inches longer than the normal version and is designed to be used at higher oil pressures (it's chart goes up to 120 psi and at that pressure for 3 quarts you're supposed to use 15 psi of air pressure).

The key is the accumulator will keep adding oil to the system until the pan has enough oil that the sump picks it up again and pressure returns, so it will only add as much oil as is needed to return to having pressure.

I see them mention a check valve is recommended in the system to prevent back flow towards the filter. I don't see one your system, and it seems to be working well, so I'm hoping I don't have to figure out how to make one fit.
 
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Bnks334

Sergeant
Dec 1, 2016
388
New York
Asbjorn, reference this thread: https://www.e90post.com/forums/showthread.php?t=581081 He's measuring pressure at the same location that the stock oil pressure switch is installed (that's what the LeatherZ setup places its sending unit), aka just after the oil filter.

From the install instructions on the electric (non pressure sensing) setups (aka part 24-270x) its designed to work as always on when the ignition is on. So I wouldn't have any worry about wearing out the valve because its always on, or else they have a very poor design. Seeing too that the valve is the same for all the applications, they just use a pressure activated switch to control the valve in the other units, I doubt it always being on is an issue.

Doing some basic math here... the moroso accumulator (which is the one I have, 3 qt, same as Bnks) is 167 cubic inches inside volume (I measured the ID of the cyl, depth at full, depth at empty, and calculated the volume). I'll fill with nitrogen so the temp effects its operation less, but you're supposed to fill it to 6 psi with no oil in it.

Thus with PV=NRT we have 0.0460982 moles of air at 72 deg F. If we change the pressure to 22 psi (what it will be at idle as the piston moves to make the pressure equal on both sides), the new volume that same mass of air takes up is: 45.5454 cubic inches. Which means the accumulator is still holding 167 - 45.5 = 121.5 cubic inches of oil. Which is 2.1 quarts.

So that means it only added 0.8 quarts to the system at idle oil pressure levels (because 167 cubic inches is only 2.9 quarts).

So I'm not too worried about that.

If you're looking at that number and going "wow that doesn't add a ton of oil until you're really low on oil pressure) that's exactly right, and that's exactly why they Accusump makes a "high pressure" version that is 6 inches longer than the normal version and is designed to be used at higher oil pressures (it's chart goes up to 120 psi and at that pressure for 3 quarts you're supposed to use 15 psi of air pressure).

The key is the accumulator will keep adding oil to the system until the pan has enough oil that the sump picks it up again and pressure returns, so it will only add as much oil as is needed to return to having pressure.

I see them mention a check valve is recommended in the system to prevent back flow towards the filter. I don't see one your system, and it seems to be working well, so I'm hoping I don't have to figure out how to make one fit.
Pretty sure the oil filter housing works as a check valve. I can prime the engine just fine when I flip the switch with 40psi+ so I know oil is being sent though the block and not just going back to the pan.

Good info and thanks for the math. I actually filled mine to like 10psi of air to get a quicker discharge. Holds less oil too that way too but I wanted to have the slightly quicker discharge rate since the time spent without oil pressure is very little blips not extended periods.
 

shushikiary

Corporal
Jun 4, 2018
141
At 10 PSI, 22 PSI is 75ci, and at 70 psi its 24ci, which means the accumulator is holding 1.6 quarts at idle (if you didn't switch it off then it would add 1.3 quarts to the pan), and has 2.5 quarts or so when you're at higher RPM oil pressure. So you've got an extra 1/2 quart in your system at all times, nothing to write home about I'd think, but I can see why then shutting it off at idle would be a bigger deal. That 0.5 + 1.3 = 1.8 quarts extra at idle isn't so awesome. If you put 3 quarts in for 6 psi, then you're only running an extra 0.4 quarts "normally" and then add 0.8 at idle, so 1.2 quarts extra at idle. I think they have you put in 3 quarts because they expect you to be running long oil lines to the accumulator.
 

Davidwarren

Corporal
Nov 6, 2016
179
Louisville
I bought an inline check valve from Summit that would keep the accumulator from just dumping back into the sump. I think that's pretty important.
 

Bnks334

Sergeant
Dec 1, 2016
388
New York
I bought an inline check valve from Summit that would keep the accumulator from just dumping back into the sump. I think that's pretty important.
I am going to put one in soon and see how the logs compare on a "prime". I can't see how it can really be an issue though with a positive displacement oil pump. Oil can't flow backwards through it. If oil from the accumulator goes backwards it will just serve to keep a positive flow of oil moving through the block all the same... unless I am missing something. Maybe you can say it's wasted energy to dump pressure into the entire volume of the oil cooler and oil filter housing instead of straight through the block but I think the difference would be negligible since we are talking about intermittent starvation and not completely bone dry.

I am also thinking the N55 oil pressure sensor is reading in absolute pressure. So 38psi at idle is really 23psi or so... and 80psi under load is really 67psi. I say this for a few reasons 1) MHD shows an oil pressure similar to atmospheric when the car is off 2) the F-series oil pressure in logs appears to be 23psi at idle and 64psi or so at WOT 3) I have seen reference made to an oil pressure sensor change in BMW F series academy docs 4) these values better match the golden rules of ~10psi per 1,000 rpms. I can see some potential value in bumping oil pressure up 10psi or so on tuned cars if the above is true.

Makes sense N54 would be similar to these values as well. Dzenno's old N54 oil pressure readings might be accurate.
 
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Asbjorn

Sergeant
Mar 10, 2018
455
Europe, based in China
So I finally got a chance to test the new custom baffle with my used 245 Pirelli DM slicks. Oil pressure stays between 90-100% throughout the track except during one left turn if I use trail braking and turn in hard at the limit of grip.

2103223753.jpg


In this case, oil pressure drops to around 50%.
To illustrate, the problem happens when the oil moves like this>

618956279.jpg


It makes no difference if I turn on or off the oil pump that moves the oil from the rear to the front.

mmexport1570255691236.jpg


So this might explain why @Davidwarren had issues although a baffle was installed.

Not sure what to do next. For now I'm removing the slicks and going back to semi-slicks like the cup 2.
 
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Davidwarren

Corporal
Nov 6, 2016
179
Louisville
Would it be totally crazy to run a damp sump using the oil cooler interface? I’m thinking a two port scavenger pump, one pulls the oil feed from the cooler plate (the “out” to the oil coolers), one pulls from the pan drain. Those dump into a remote tank. Then use the oil pressurizing pump to the cooler “in” feed.
Get an ATI damper from VAC, add a gilmer pulley to the face, and run a dry sump pump mounted where the a/c compressor mounts.

then you can have a 12qt tank in the trunk and never run out of oil.
 

Asbjorn

Sergeant
Mar 10, 2018
455
Europe, based in China
A correction to my post above. I just installed cup2s and did another track session. The oil pressure dropping through turn 8 is definitely still there. So this is also an issue with semi-slick tires (if you can call cup2s that).
 
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Relegate

New Member
Oct 8, 2019
4
Hey guys! I'm new to this forum and have been lurking as I'm part of the dead N55 club from tracking. Man, it's been great to see this thread and thanks to @Bnks334 for cluing me in a couple months ago. This winter I'm going to have the engine torn down and rebuilt, and at that point we are going to address the oil pan baffle. I have been told by a lot of guy to run and accusump as well as the dual oil coolers since those will increase oil volume. I'm likely going to do a Stage 1 turbo upgrade as well (any recommendations of the new(?) Vargas vs Pure would be cool).

Have you guys had a chance to get out on track with these upgraded pans and accusumps lately?

If you were to put together a check list of N55 rebuild and track readiness, what would be on it? (Baffled pan, bigger coolers, WPC coated bearings, etc).

Thanks for all of your time and effort in this. I also have some M Control arm Q's I'll post separately.
 
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Asbjorn

Sergeant
Mar 10, 2018
455
Europe, based in China
I wonder if you need an accusump now too. Aren't you just running the pump and no accusump?
Yes, but I cant seem to figure out whether I am just overly concerned here. My oil pressure drops to an indicated 60psi from 90-100psi. It is not like the oil pressure gets even close to idle pressure. To have an accusump set to work at 70-80psi to avoid that particular left hand drop doesn't sound right at all.

Anyhow, today I realized the that my oil level just dropped from max to 80% in iDrive. This means that when I was on the track testing, some 300kms ago, the oil level must have been more or less exactly at max or just above. Because, to my knowledge, my car doesn't use alot of oil.

I remember the M4 GTS uses an extra litre of oil over the standard M4. Question is if I just just try and add a liter of oil right now, then go back on track and test again.
 

Asbjorn

Sergeant
Mar 10, 2018
455
Europe, based in China
Hey guys! I'm new to this forum and have been lurking as I'm part of the dead N55 club from tracking. Man, it's been great to see this thread and thanks to @Bnks334 for cluing me in a couple months ago. This winter I'm going to have the engine torn down and rebuilt, and at that point we are going to address the oil pan baffle. I have been told by a lot of guy to run and accusump as well as the dual oil coolers since those will increase oil volume. I'm likely going to do a Stage 1 turbo upgrade as well (any recommendations of the new(?) Vargas vs Pure would be cool).

Have you guys had a chance to get out on track with these upgraded pans and accusumps lately?

If you were to put together a check list of N55 rebuild and track readiness, what would be on it? (Baffled pan, bigger coolers, WPC coated bearings, etc).

Thanks for all of your time and effort in this. I also have some M Control arm Q's I'll post separately.
So regarding dual oil coolers.... I have a large setrab type oil cooler connected to the oem thermostat, and I still have the problem described. If the engine oil pump picks up air, I dont think it makes any difference how much oil is sitting in the oil cooler? The in/outlets are located on the top of my oil cooler, so the air would just push right though.

I also have a second oil cooler, which is driven by an electric pump connected to the front and rear of the oil sump, circulating the oil in the oil pan. I did try turning that pump on and off, and it doesn't make any difference in regards to the oil pressure issue. It just lowers the oil temps a bit. The oil is moved from the rear of the pan, ie out side the baffle, to the front of the pan. It makes sense that it doesn't help with oil pressure, because the issue happens when I trail brake, where the oil would already have moved towards the front of the baffle. In fact it might help to reverse the pump, but then I have the issue where it might run dry when accelerating. The rear of the pan is lower than the front.

And in general I would say, spend all the available cooling space on radiators instead of oil cooling. Three days ago a friend of mine hit +118C with this S55 on track, while his oil temps barely moved past 120C. My M135i friend would also hit power reduction due to coolant rather than oil temps here in the southern chinese humid heat.

If you update rods and bearings, you risk a bad installation which could lead to premature failure. Really I would say the easy answer is to go S55. It also has a pump to pull oil from the turbos under high G forces.

Regarding turbos for tracking you need something with headroom, so they have an easy job, and a turbo that uses the best exhaust wheel material that can handle the elevated egts. Look at the M235i racing. OEM turbos and less than stock power. That is my best advice. But you wont listen to that hahaha - I certainly didn't myself. Also look at the M235iR control arms for great inspiration.
 
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