S54 Dry Sumped engine oil pressure problems

[said]

Hello Guys!

Hoping your knowledge on this engines can help me out.

So, i have 2 S54b32 engines, 1 is a Stock built and the other is race built. Difference between them is that race engine has 280/288 cams and more loose clearances, all within BMW spec.

Both engines have an external dry sump pump, 1 pressure and 3 scavenge, they only share the cars plumbing system, external pressure regulator and tank.

The stock engine builds up pressure immediately after priming the oil pump, and i see 5 bar pressure (cold, with 10W60 oil) and then goes down to 1.5 when hot. Vanos gets around 130 bar cold and then 105/110 hot. I believe this numbers are amazing for engine health.

Problem comes with the race engine. After pump priming, engine builds up only 3 bar at idle, and goes down to 0.5, 0.6 when hot, and vanos gets into 30/40 bar. If i leave the car for 3 days with out use, i have to prime the pump manually again, if i start the car without priming, pressure is 0 bar!! (Stock engine builds up pressure immediately after 1 week if you’d like)

Tried swapping pumps, same problem.

Race engine has a new vanos unit from Dr Vanos.

• Both blocks have the original pump feed blocked with a screw, so i don’t think this is the problem.
• checked the rocker arm shafts, Exhaust is blocked with a screw (bough it new)
• CPV is not new, but should be working, seal changed for a viton one.
• Vanos pressure regulating valve is new

To be honest, stock engine was built with race leftovers, the one having great pressure should be the race one! I bought both cylinder heads on eBay and then installed them into each engine, maybe they are missing a plug or so? I have checked everything visually but all is there.

I just don’t know what else to check, suggestions will be amazing please!

[eacmen]

I don't have any answers for you but this thread on e46f is worth a read:

https://www.e46fanatics.com/threads/solved-s54-rebuilt-but-low-oil-pressure-at-idle.1288756/

Also not an expert but I know there is some talk of aftermarket cams not having some kind of valve in them. You should be able to search around for some threads on the topic.

[said]

I don't have any answers for you but this thread on e46f is worth a read:

https://www.e46fanatics.com/threads/solved-s54-rebuilt-but-low-oil-pressure-at-idle.1288756/

Also not an expert but I know there is some talk of aftermarket cams not having some kind of valve in them. You should be able to search around for some threads on the topic.

Thanks for replying

i didn write in that post too!

Checked my cams, they do have the check valve on it... but maybe its stucked?

[heinzboehmer]

What rod bearings did you use/what was the clearance to the crank? I remember someone on here had an issue with ACL race bearings where the clearance was too large and caused low oil pressure.

[Anri]

Hi Said,

We need way more Technical info on your dry-sump parts compared to what you have posted.

Forget about the OEM system..of course it works great and you don't have to even compare
the readings vs your dry sump readings.

I have a lot of questions and I don't know were to start...but let me try.

What brand is your dry sump pump ?
How big is the rotor OD, Width ?
How many lobes/gears does it have ?
What are the Pulley Sizes ? (I can calculate the speed and compare it to std)
What brand is the oil pan you are using ?
Were are the 2 suction piping located/welded in the pan ?
Assuming the std oil galleys are plugged ?
Make sure there are no kinks in the lines.
A simple feedback and a note when you rev the motor what
is going on in the dry sump tank ?
Is this Brand New pump or used ?
How is the pressure relief valve set, piston wear ? checked ?


All Dry sump manufacture companies want to spin the pump at low speed
as possible..to avoid aeration/cavitation and also wear.

This should be a good start.

Regards,
Anri

[said]

What rod bearings did you use/what was the clearance to the crank? I remember someone on here had an issue with ACL race bearings where the clearance was too large and caused low oil pressure.

Have had this problems with any rod bearing brand, VAC, ACL

Mains are ACL bearings, running 0.0018 clearance
Rods are VAC Coated, running 0.0025 clearance

I use to run this clearance on the stock engine when it was my main race engine, and havent had any troubles..

i belive the answer is somewhere in this new race engine block or cylinder head.

Loose clearances with a dry sump pump is never a problem, the pressure generated its just too much

[said]

Hi Said,

We need way more Technical info on your dry-sump parts compared to what you have posted.

Forget about the OEM system..of course it works great and you don't have to even compare
the readings vs your dry sump readings.

I have a lot of questions and I don't know were to start...but let me try.

What brand is your dry sump pump ? Peterson Fluid Systems
How big is the rotor OD, Width ? 1.4" Rotors
How many lobes/gears does it have ? 4 stage, 1 pressure 3 scavenge , Model number is Peterson R4 04-4072
What are the Pulley Sizes ? (I can calculate the speed and compare it to std) Pump Pulley is 3.312" OD 1" Wide and 28 Teeth - Crank Pulley is 18 Tooth 1.10 Thickness, i need to confirm OD
What brand is the oil pan you are using ? Its a Moroso pan, from VAC motorsports
Were are the 2 suction piping located/welded in the pan ? it has 3 suctions, and the back of the pan
Assuming the std oil galleys are plugged ? yes, the main galley from the oem pump is tapped and it has a screw on it
Make sure there are no kinks in the lines. no kinks
A simple feedback and a note when you rev the motor what
is going on in the dry sump tank ? cant really take a look, tank is sealed
Is this Brand New pump or used ? this one is almost brand new, it has around 3 hours use.
How is the pressure relief valve set, piston wear ? checked ? its new, i did a remote unit with a much bigger piston.

Remember both engines share the same tank, plumbing, remote relief valve, and also both pumps have same configuration and pulleys.


All Dry sump manufacture companies want to spin the pump at low speed
as possible..to avoid aeration/cavitation and also wear.

This should be a good start.

Regards,
Anri

Hello Anri!!

Ill answer all the questions in your post!

thanks!

[heinzboehmer]

Have had this problems with any rod bearing brand, VAC, ACL

Mains are ACL bearings, running 0.0018 clearance
Rods are VAC Coated, running 0.0025 clearance

I use to run this clearance on the stock engine when it was my main race engine, and havent had any troubles..

i belive the answer is somewhere in this new race engine block or cylinder head.

Loose clearances with a dry sump pump is never a problem, the pressure generated its just too much

Cool, just trying to make sure the clearances had been checked.

And yep, you're right. Dry sump should change things quite a bit.

[sapote]

Problem comes with the race engine. After pump priming, engine builds up only 3 bar at idle, and goes down to 0.5, 0.6 when hot, and vanos gets into 30/40 bar. If i leave the car for 3 days with out use, i have to prime the pump manually again, if i start the car without priming, pressure is 0 bar!! (Stock engine builds up pressure immediately after 1 week if you’d like)

Whatever the leaking source is before the head: it drain all the oil leading to a dry pump after 3 days, so I don't think it is in the head.
I would check the check valve in the oil filter housing.
How is the external pump output fed to the oil filter housing?

[said]

Whatever the leaking source is before the head: it drain all the oil leading to a dry pump after 3 days, so I don't think it is in the head.
I would check the check valve in the oil filter housing.
How is the external pump output fed to the oil filter housing?

Filter housing is gone. I use a billet housing from VAC. a -10AN hose feeds directly

yes, there is something open inside the block, and it’s making the pump struggle all the time

[sapote]

So it has an inline-oil-filter? Does the VAC oil filter housing have an anti drain back valve to keep the oil pump full with engine turned off?

[said]

inline filter yes

no valve in the housing, this housing is also shared with both engines

So it has an inline-oil-filter? Does the VAC oil filter housing have an anti drain back valve to keep the oil pump full with engine turned off?

[said]

Hi Said,

We need way more Technical info on your dry-sump parts compared to what you have posted.

Forget about the OEM system..of course it works great and you don't have to even compare
the readings vs your dry sump readings.

I have a lot of questions and I don't know were to start...but let me try.

What brand is your dry sump pump ?
How big is the rotor OD, Width ?
How many lobes/gears does it have ?
What are the Pulley Sizes ? (I can calculate the speed and compare it to std)
What brand is the oil pan you are using ?
Were are the 2 suction piping located/welded in the pan ?
Assuming the std oil galleys are plugged ?
Make sure there are no kinks in the lines.
A simple feedback and a note when you rev the motor what
is going on in the dry sump tank ?
Is this Brand New pump or used ?
How is the pressure relief valve set, piston wear ? checked ?


All Dry sump manufacture companies want to spin the pump at low speed
as possible..to avoid aeration/cavitation and also wear.

This should be a good start.

Regards,
Anri

BTW

OEM Engine is also Dry Sump, so comparing both engines should not be a problem at all! they both share many things.

[Anri]

Said,

It is very difficult to diagnose "online" this specific problem because.
there are many things to go off..

I'd say you need to reverse your work and start looking into
the schematics and follow the pressure.

Assuming the engine is put together properly and that is out
from the list.

By the way the 3 stage VAC oil pan is garbage....very poor
design !!!!! They offer other "Kit" with everything but its $6000+
and that is very good set up.

If not mistaken I recognize you name with E30M3 S54 swap ?

Regards
Anri

[said]

that kit you talk about is the billet one, but yes, no way I will spend that money. The one I have works well scavenging the oil.

e30m3 s54 is me! Haha

i think I might have found the problem, Intake cam has 0.5 mm of axial clearance, I will now measure the round clearance there, might be big and oil is coming out like a Faucett

Said,

It is very difficult to diagnose "online" this specific problem because.
there are many things to go off..

I'd say you need to reverse your work and start looking into
the schematics and follow the pressure.

Assuming the engine is put together properly and that is out
from the list.

By the way the 3 stage VAC oil pan is garbage....very poor
design !!!!! They offer other "Kit" with everything but its $6000+
and that is very good set up.

If not mistaken I recognize you name with E30M3 S54 swap ?

Regards
Anri