dlpalumbo

I've read on this forum and elsewhere that 964's are prone to failure of the 3rd cylinder rod bearing. Further reading uncovered that this is not solely a 964 issue, but stems from the way the oil journals run through the system on 911s with the 3rd cylinder being last in line for oil. The failure mode was oil starvation causing poor oil supply to the 3rd cylinder.

So my question is, in the 911 dry sump setup, how does oil starvation occur??

Is it g-forces around a left or right turn?? Is it low oil supply??

Just wondering what's lurking around the next bend.

Thanks,

Dan

Steve Weiner-Rennsport Systems

Its due to operating at RPM's above 7300K for periods of time. These engines do not have oil starvation issues.

KaiB

So...for an engine designed to operate above 7300 at times, what modifications must one make.

Given that yer at Rennspor Re-onion, you might see a few of these engines, huh?

Steve Weiner-Rennsport Systems

For safe, sustained operation above 7300, one cross-drills the center main journal on the crankshaft, modifies the case to suit, and grooves the center main bearings. Naturally, a larger oil pump is used as well.

Unable to attend RR IV so I'm working diligently on our new website.

FeralComprehension

Plus.... rod bolts, valve springs, valve keepers and _____?

And probably cams to be able to take advantage of the increased operational envelope?

Marc Shaw

....and lighter pistons too.

Marc

dlpalumbo

Good to know.

Thanks.