[E92Fan]

Originally Posted by atomic69

Looking a the pics there look to be some heat issues with the big end's. There could be many reasons for this and without some data logs it would be difficult to say conclusively.
You have chosen your components and manufactures wisely and I would rate CP-Carrillo as being one of the top three manufactures in the world along side Arrow, Omega and Cosworth. Aftermarket pistons tend to be made from low expansion alloy forgings like 2618 or 4032 as they are far more resistant to high loads and temps than oe pistons. As you are not doing things by half if I were you I would also contact Vandervell and see if they could produce you some Mahle Motorsport bearings to suit. Mahle's Motorsport cast bearing are without doubt the best available and offer far better load characteristics than other manufactures "Race" bearings which tend to be just standard bearings that are hand picked and checked for dimensional tolerances.
As for oiling issues, unless you go to the trouble of installing a dry sump your only real choice would be to install baffles and install an Accusump. The Accusump's work very well for what they are and have a race proven record, being used in the likes of the BTTC etc. Modifying the oe oil pump to increase flow and possibly pressure is also something to consider.

Great information and thank you for your input. I agree entirely with your thoughts on CP-Carillo and hence why I used them to manufacture the engine parts for me. I have already thought of the Mahle bearings (CP actually advised me on this!) and things are 'in process'!

I've also been looking at dry-sumping and have figured out a way of doing it successfully, but the problem is that there isn't enough clearance above the engine. The engine would need to be lowered in the bay, with ramifications for the ancillaries and the steering rack. It's a real ball-ache!

I already have an Accusump (3qt high pressure) and I think with the pan baffles this will be a suitable combination of devices to maintain oil pressure under heavy load.

Originally Posted by m1bjr

Im amazed you did all this work so far but didn't dry sump already..

BTW a degree of det will see of the crown and ring lands like that - or a failing fuel delivery from a shot injector.
I have done it on a big bike engine, and went the big-bore Wiseco route to fix the liner gouges.

See above on the dry sump issue

And yes, you are right a degree of detonation can cause much of the damage.

Originally Posted by 335i E92

Tony

Informative & indepth as ever!!

As one or two have commented on here the amount of damage and wear for 50k is shocking. This thread as interesting as it is will now doubt be causing concern / panic for many on here that are running mods on the n54.

Just to try to ease everyones minds a little i think it only fair to push the point that your car whilst regularly serviced has been pushed to the limit & tracked many many times. Whilst the carbon build up is a definate worry (even with a CC) I wouldn't expect anywhere near that kind of wear on engines for the majority of n54 owners out there who are enjoying the performance of thier mods on the road and only exposing the car to medium level temps.

There are probably many on here like myself who drop thier oil every 5k and whilst modded at 370bhp + don't push their car to extreems. Don't get me wrong Ill have times when I drive the car hard but not for extended periods of time and I personally back off everytime my temp gets to 120c.

As you've mentioned alot of the damage is heat related, what sort of temps have you seen on track days?

Best of luck with the rebuild, You really are a pioneer of the n54. Hope you get her back on her feet n fitter than ever ready for some Nurburg action

You are quite right - the damage shown in this engine is not representative of the state of N54 engines around the world. There are other underlying issues here which won't occur with other owners.

However it is worrying that so many people in the States in particular are chasing ever increasing amounts of horsepower, and yet pay less than zero attention to the ancillaries or supporting products that are needed to maintain that reliability. The pictures of my engine should serve as a wake up call to all those running 18psi boost pressures on race maps etc etc...

Originally Posted by Yahoo

OK. So, could the problem be that the oil is thicker at higher operating temps?

Please bear in mind that I have little knowledge of fluid dynamics and continually bow to your knowledge of all things N54 Tony - however, I would like to explore whether this hypothesis holds water.

If the problem is due to pistons getting too hot, expanding and scoring the cylinder walls, this surely points towards a lubrication issue. The purpose of engine oil being to lubricate all moving parts, preventing metal:metal contact, generating too much friction/heat and damaging components.

So, could this be due to the following conditions / characteristics of your engine:
1) Blueprinted engine = tighter tolerances between moving parts than a stock N54.
2) 5w-40 oil = thicker engine oil at high temps = less flow to moving parts at high temps then with recommended 5w-30 oil.
3) Sustained track use = sustained higher temps then would be experienced then 99.9% of N54s on the road.

Could these circumstances lead to expanded pistons, even tighter tolerances, less flow of thicker engine oil to components, more friction, increased heat and so on?

If so, this would become a vicious circle of friction, heat, lack of lubrication leading to this type of engine wear.

After the initial premature engine wear, once cooled, the tolerances between pistons and cylinder wall would become larger increasing blow by and carbonisation.

Out of interest - which catch can are you running?

The 5W-40 is definitely NOT the cause of any of this wear. The oil is nowhere near too viscous at operating temperatures and having been speaking to so many engine builders and experts, they have actually advised the opposite. With the temperatures that I run the engine at, typically 125-130 degrees oil temperature at the 'Ring, they have suggested that I should run a 5W-50 oil to ensure high-temperature oil structure and pressure is maintained. The thinner the oil, the lower the oil pressure and at high temperatures a 5W-30 oil or 0W-30 is thinner than a 5W-40. It's certainly not an issue of lubrication in itself (as can be seen by the oil seepage past the rings) but more likely of oil pressure.

Originally Posted by ///ajd

Very interesting Tony,

There is also an interesting thread on PH in relation to the latest DI 997 engines. Ian_UK1 is looking to get his internals boroscoped soon at an indie garage.

What do you think the bigger issue is - oil seeping past the valve stems, or oil from recirc'd air? Catch cans obviously only help with the latter.

http://www.pistonheads.com/gassing/t...997?&mid=78451

I think a lot of the issues being seen are a result of oil vapour recirculating into the intake system, and not having petrol washing over the valves to effectively 'clean' the system. Direct injection has many benefits, but it may be that we are seeing one of the downsides to the new technology. I'm no expert on DI techniques and solutions so this is only my own hypothesis.

Originally Posted by atomic69

If you are seeing oil temps 120degC of a fairly regular basis then you need to look into additional oil cooling. If you wanted something nice and discreet then a Laminova type oil cooler would be ideal.

BMW have designed this N54 engine to run an average oil operating temperature of 115 degrees. For whatever reason, they want it running hot. The Motorsport engines run at 130-135 degrees. I already use a double oil cooler system using Setrab cores. I might change over to a Laminova cooler - still thinking about this.

Originally Posted by zltm089

Can I ask how much bhp you getting from the engine?

A lot