CCV delete

[Jason5driver]

Remember that the port to which I have the new vacuum line connected is post-oil separator, so nothing is going into the intake that wouldn't have gone there with the factory arrangement. I am not concerned, as the whole point of the modified setup is to minimize the amount of oil pulled into the cylinders by promoting better sealing.

The idea of using exhaust scavenging was brought up in my thread, but here's the problem: the ring flutter issue occurs at times of high manifold vacuum, which in turn are points of low exhaust vacuum. In other words, the exhaust vacuum occurs at the wrong time for it to adequately offset the high vacuum in the cylinders.

Yep, I agree.
That is why I think most guys run the Exhaust Scavenge system with an added Vacuum Pump as well, to help supply constant vacuum.

IMO, the idea makes sense, however, I am not too sure about the added electrical load, and adding one more part to break...
LOL!

Reference this thread on the M5 Boards:
http://www.m5board.com/vbulletin/e39...harger-m5.html

Plus, I am not too hot about possibly contaminating the Exhaust Cats when connecting/exiting the blow-by into the exhaust...

PS,
Did you ever measure the current Crankcase pressure as per "BMWdirtRacer's" request with your home-made Manometer...?

His post from your thread:

Then there's always the rear water manifold, and the lovely rear coolant cover, hidden inside the bellhousing.

I dare say BMW's V8 engines leak as much of everything as any British P.O.S. ever built. (Note that I lived and raced in England for seven years - and that I really love Vanos, non-valvetronic V8s, leaky sumbitches that they are)

Living in a mild climate, I like heavier oils, and now use Castrol Edge 20/50 in both my cars. Admittedly, they're both old-school engines, so this isn't directly related to the issue, here.

02 pilot, have you looked at your crankcase vacuum since introducing your mod? I'd be curious....

Have you performed a recent Oil Analysis...?
I would be interested in seeing the differences in your car's oil before, and after you added the vacuum hose...

Thanks!
Jason

[02Pilot]

Haven't done a UOA, so I can't give you anything there. I run strict 5k mile changes, so I wouldn't expect much in the way of degradation on full synthetic in any case.

Crankcase vacuum was checked multiple times with the mod in place, though I have not rechecked it in some time. The numbers are quoted in the post, but they may be buried in there, so I'll repeat them here: in normal operation the crankcase vacuum is very similar to the standard spec of 4-6" of water; at idle vacuum rises slowly to plateau at ~5" of mercury; on prolonged deceleration, I have seen a high figure of ~10" of mercury. I forget the exact conversion rate, but it's readily available if you want to do the conversion math.

[Jason5driver]

Here is a great thread to reference...
http://forums.bimmerforums.com/forum...rank-case-vent

Thanks!
Jason

[02Pilot]

There's a lot of information in that thread, but nowhere do I see (in an admittedly quick browse) any discussion of WHEN you want to apply additional vacuum to the crankcase. My theory (see the aforementioned long-winded General Mechanical Forum post for details) is that ring flutter occurs when the vacuum differential between the cylinders (high vacuum) and crankcase (low vacuum) is greatest: under small throttle opening. This means that you need to reduce the differential vacuum in that condition, which in turn requires that you apply additional vacuum to the crankcase under that state. The exhaust scavenging arrangement does not do this; it only applies increased vacuum under large throttle opening (when exhaust flow is greatest), precisely when you do not need it.

[16valex]

The Exhaust Scavenge system with an added Vacuum Pump sounds to me is a waste of money and labor intensive for no gain whatsoever in the war against oil consumption in an M54 engine.

Tell me if I'm wrong. Does anyone here has done the mod? And does the mod help reducing oil consumption? I would love to hear the results.

I did the O2pilot mod and so far it has reduced the oil consumption by about 30%. That's still good news. But what I like the most about the mod is it's very simple to do, it takes no more than an hour, costs about 10 dollars max.

[Header]

Old thread I know, did you check your fuel trims after mod . mine went over limit