Quote:
Originally Posted by AZ986S
I admire what Chris Cervelli is doing for the dry sump solution, and I had read that post. The problem is that he does not say what the issue is, only somewhat vague statements on how some common fixes don't help, namely, Accusump, extended oil sumps, oil baffles and Dual scavenge pumps. No doubt the ultimate solution IS Dry Sump, but, to what the Radium King said, why did the X51 and all subsequent engines have an additional oil scavenging pump if that is not at least part of the issue? Also, how can an Accusump NOT help, even if oil is pooling in the heads? Accusump also adds a couple quarts of oil to the system, so that certainly helps to keep temps down. So, short of spending $20K on a dry sump system, I'll go with the "band aids" for now  |
I'm with you and your thoughts mirror the reasons I started the thread. I'm also with you on the cost issue, but if you follow the cost argument further...what if the most important factor is driving style and the band aids actually do nothing to stabelize oil pressure and are purely there for as a comfort blanket and to fill vendor's pockets? If so we might as well just stop after doing all cooling mods (confirmed) and just drive...We keep the money for a future rebulid. Unless the mods add power of course.
The reason I'm sceptical to the accusump is that I have read, and I suspect, it simply has too much lag to fill in the pressure dips. Also, all air bubble sucked in by the pickup, (or from pump cavitation due to high RPMs?)is already in the systen when the pressure drops and the only way to purge it is via the bearings. As Chris says it may help for extreme cases where the pickup continues to suck air for a longer period, but that is not what is causing pressure dips. If you have lost pressure for that long you have also lost your engine, in my opinion.
When it comes to the dual scavenge pumps they may be needed for other issues.In more powerful high-revving engines where the oil flow is higher. Pooling, backpressure and areation from the moving valve train come to mind. Anyway, they surely can't hurt our engine.
Chris states that the X51 baffles may work in the rear mounted 911s, but if the logs show the same pressure dips as before the installation in a mid-mounted engine it clearly does not alleviate the specific problem of pressure drop spikes in our cars, at least not in the tested engine.