BMW S65 engine ?

[RandyB]

None of the GT3 variants have DI either, including the latest 3.8 liter although the Carrera S 3.8 has it.

[footie]

South,

You are quite right, Audi's FSI (DI to everyone else) usually runs between 100-120bar. I don't know if this is the sole reason why their system seems to be running fault free but any difference between each system may be the explanation.

It's funny that the 8700rpm 5.2FSI only uses 120bar so maybe looking for 200bar might be overkill.

[Bx Tpr]

Originally Posted by Gearhead999s

The feeling is that without the back of the valves being in the fuel stream the additives in the fuel cannot clean that area which is caused by the blowbye in the crankcase ventilation system.

Very interesting, very true and something I would've never thought of if someone didn't mention it first. Every time I've opened up an LS1 or even my current Hemi and peered inside the heads, I noticed that the tops of the intake valves were spotless.

How is the positive crankcase ventilation (PCV) system setup on the S65? Are catch cans available for the M3?

[Propellorhead]

AFAIK, DI wasnt considered when developing the s85 V10 (of which the s65 is derived). My guess is they didnt/couldnt spend the extra time/money in development to switch to DI, which one would assume involves quite a bit of redesigning on the top end of the motor at the very least.

[Gearhead999s]

Originally Posted by Bx Tpr

Very interesting, very true and something I would've never thought of if someone didn't mention it first. Every time I've opened up an LS1 or even my current Hemi and peered inside the heads, I noticed that the tops of the intake valves were spotless.

How is the positive crankcase ventilation (PCV) system setup on the S65? Are catch cans available for the M3?

This was a problem back in the early 90's with the fuels being used at that time.My street 325is (which was driven very hard)at that time had huge deposits on the back of the valves that had to be cleaned with the walnut shell blasting that was used by the BMW dealers at that time as it was a very common problem.The modern fuels with the additives used today seemed to have eliminated this problem,or at least on port injected engines.

[kmac1980]

After extensive discussion in another post with Sticky and Footie we concluded:

Audi DI motors > BMW motors

right Sticky?

[likestogofast]

I have a question, Why doesn't high performance engines (Race Engines) use Direct Injection..? most of what I see are shower injection, or carburation.

[footie]

Originally Posted by likestogofast

I have a question, Why doesn't high performance engines (Race Engines) use Direct Injection..? most of what I see are shower injection, or carburation.

I would imagine it has all to do with the complexity of the software and mechanics of those extreme high revs.

Example: an F1 engine revs to approximately 19000rpm, that is 158 spark ignitions per second for each cylinder, or one ignition every six thousandth of a second. The fuel/air mixture is drawn into the cylinder, compressed by the piston and ignited by the spark plug; then the flame front travels through the entire combustion chamber, the combustion gas expands and, by means of the pistons, provides the engine's power before being discharged through the exhaust ports. All this happens 158 times a second in each of the 10 cylinders.

I just don't believe the technology is there yet.

[Sticky]

Originally Posted by footie

I would imagine it has all to do with the complexity of the software and mechanics of those extreme high revs.

Example: an F1 engine revs to approximately 19000rpm, that is 158 spark ignitions per second for each cylinder, or one ignition every six thousandth of a second. The fuel/air mixture is drawn into the cylinder, compressed by the piston and ignited by the spark plug; then the flame front travels through the entire combustion chamber, the combustion gas expands and, by means of the pistons, provides the engine's power before being discharged through the exhaust ports. All this happens 158 times a second in each of the 10 cylinders.

I just don't believe the technology is there yet.

Not every race motor has high revs and DI is not going to provide a benefit in efficiency in unrestricted motors. Simply put, there is no point.

If port injection was illegal in F1 and DI wasn't you would see it, regardless of RPM.

[icemang17]

my guess is cost.....bottom line is DI costs more and the basic engine design of the S65 was already done with the V10...they just tweaked a few little things

[G80indy]

Port injection rather than DI was a motivation for me to get the S65.

[NA V8]

Originally Posted by 330indy

Port injection rather than DI was a motivation for me to get the S65.

+1

[M3AG]

Originally Posted by mixja

Direct Injection provides better atomisation because the fuel is injected at much higher pressure. I'd say it was more a cost vs benefit thing - the performance gains would not be significant...

With DI, you save more on gas...

[CrucialScott]

Originally Posted by 330indy

Port injection rather than DI was a motivation for me to get the S65.

But Audi is having big problems with intake deposits on their direct injected engines at least in Canada.The feeling is that without the back of the valves being in the fuel stream the additives in the fuel cannot clean that area which is caused by the blowbye in the crankcase ventilation system.This is much worse of a problem in areas of cold ambient temps like Canada.interesting that BMW is not having the same problem with the twin-turbo 3.0 L.A buddy with an RS4 has had to have the intake blasted with walnut shells twice to remove the deposits allready in order to cure the drivability problems that are caused by this problems.

Exactly why i was put off the RS variants of the Audi's...So many problems! You can lose up to 100BHP due to clogged ports!

Glad we don't have silly DI

Plus is would seem like something else to go wrong with the forever growing list of common problems with the E9X M3...

[MRV99]

4year old thread revived. Well done!

[G80indy]

Originally Posted by CrucialScott

Exactly why i was put off the RS variants of the Audi's...So many problems! You can lose up to 100BHP due to clogged ports!

Glad we don't have silly DI

Plus is would seem like something else to go wrong with the forever growing list of common problems with the E9X M3...

Hmmmmmm what's the list in short of common m3 problems?

[Jive]

Holy thread necro.

Originally Posted by 330indy

Hmmmmmm what's the list in short of common m3 problems?

Engine ticking is the first one that comes to mind. I dont know if there is an official list.

[GIdriver]

Freaking ACLS on this thread!!!

[G80indy]

Originally Posted by Jive

Holy thread necro.



Engine ticking is the first one that comes to mind. I dont know if there is an official list.

Yes it was a thread jack, but it's so old figured no one would mind.

Yep, noticed the noise on many a test drive with pre-owned cars with 35-40k miles, especially at startup.
Coming from an S54, NBD, but I attribute this to aggressive valve clearances for the M engines.
I do plan on short OCIs.