SpeedyD

Interesting to see the 5% rate for 997.2 now that the platform has fully matured (>10yrs for all vehicles on road) vs the 20% for 997.1… we can expect both rates are overstated but it implies effectively no meaningful risk for the 997.2, essentially as expected.

The market values reflect this as well. The probability of failure appears to drive a significant amount of the discount (for equal miles and equal format) of the 997.1 vs 997.2…

groovzilla

Don't rest until you've done a Bore Scope Inspection on your 997.2. At least you can try some preventitive measures if it's scored.
997.1"S" engine more prone to scoring but 997.2 cars showing scoring as of late. I'm thinking we will see more 997.2 cars showing Bore Scoring next couple years and 997'1 cars have hit a plateau.
........I understand 997.2 owners are very defensive/touchy like PDK owners but it is what it is.

bgoetz

very little can be implied by those #s. Generally I think most would agree the 997.1 has a higher likelihood of scoring, but there are MANY things that are unaccounted for in the survey. I am actually a bit surprised by the amount of 997.2 that have acknowledged scoring, especially given the tone of the thread.

Slakker

Only about 15% of the 9X7.1 failures we see are related to bore scoring. And only half of the engines that we've gotten in that were diagnosed by a shop as having bore scoring, actually did. It's a really tough conversation to have after we've completely torn down the engine. So I now ask to see the diagnostic pictures and try to do a thorough remote diagnosis of their issues before I will send an estimate if their motivation for the rebuild really is bore scoring.

Spun rod bearings account for 80% of the failures, from both street and track use. While these engines do have some design flaws from the factory, they aren't near as fragile as their reputation. Or at least they wouldn't be, in my opinion, if Porsche hadn't spec'd 0W40 and lengthy change intervals during which time the viscosity modifiers breakdown and exacerbate the issue even more. My best guess is that their motivation was not only better mpg to meet EPA standards, but also because the lifters tend to tick at idle with heavier oil. Add a little throttle and it goes away. But what's worse, ticking lifters, or catastrophic failure from spun rod bearings?

If our customers use an Xw40 in one of our engines, they risk voiding their warranty. Dt40 is a good oil, but even new, it turns into a 30w at 223F and DT50 is the same price. Same goes for Xp9 vs XP6. For track cars that are exceeding 245F, it is essential that they move to a 10W60 in order to adequately protect their engine. Which in and of itself decreases oil temps and engine wear. It's that simple, stepping down from soapbox now.

TRINITONY

Stay on yah box..lol...so as a noob - what oil woud you recommend for a high mileage 997,1? TIA

silver_tt

Thanks Brandon for the information. It's not a soapbox, oil viscosity is extremely important and we appreciate your input. That 50% figure is shocking but at the same time not surprising. I have seen countless examples of this including what feels like every cylinder photo that is posted to RL someone says, or says their indy said, is scored or cracked. Sometimes it is and sometimes it isn't. Your and Lee's engine gurus group has been great to see a lot of real life examples and I have learned a lot from it because it is moderated by professionals, thanks for setting that up. Lee has also always been very friendly, polite, and he corrects misinformation which is helpful to the community.

SlakkerRacingDev

Thanks guys.

For oil, I still like M1 15W50 as sort of a baseline for street or track use. 5L for $25 at Walmart makes it easier for a lot of people to spend another $60 on a used oil analysis, which will not only guide them on what oil their engine likes but also serve as an early warning system for when bearings are starting to fail or cylinders are starting score. With the exception of taking the car to the track with 5,000 mi 0w40 filled to the min line and spinning a rod bearing, most of the time the issues are progressive and can be spotted well in advance and actions can be taken to prevent further deterioration.

For street use, stepping up to a DT50 or a Motul 8100 power 5w50 will usually show a slight decrease in wear metals.

For track use, Motul 300v, Amsoil dominator, M1 racing oil, and Xp6 are all oils that I’ve seen good results with.

These aren’t the only good oils out there, these are just the ones that I have the most experience with. Liquidmoly seems to have a strong following so I have a couple of customers that have started out with it but dont have enough reports back to make a determination.

For change interval of a healthily engine, we used 7-10 track hours or 4-5k miles with 1 track hour equaling 500 miles for mixed use.

We don’t worry about time based change intervals as I have yet to see any data that suggests time is a factor with modern synthetic oils and additive packages.

carguy999

Man I just switched to DT40, after switching from LM. I gotta pick something and stick with it.

Also -- you are living my dream "retirement" life - I hope someday I am set up to do something similar.

SpeedyD

LOL, I know you fantasize about bore scopes but no, I won’t bore scope by 997.2 unnecessarily. That is just dumb. At a real world rate of <2% it is not reasonable to bother doing. Never mind all those cars driven year round in freezing climates also being part of the pool of cars from which that sub-2% rate comes from. Just silly.