Bore scoring
#61
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we used to think that was the case, but just in the last week we were made aware of 2 or 3 997.2s where scoring was just discovered, so looks like they're better, but not as "bulletproof" as we thought a year or so ago.
To the OP, you can't really compare a 911 to anything else, because it's the only rear engine platform currently available which is part of what makes it so special.
To the OP, you can't really compare a 911 to anything else, because it's the only rear engine platform currently available which is part of what makes it so special.
Good point. I think since the 9A1 based cars are now way out of warranty, they're seeing their way into the hands of DiYrs and independent shops. This will reveal more of the good, bad, and ugly with the Alusil closed deck cylinder technology. For what it's worth, SUMEbore cylinder technology in post 2019 Porsche cars is showing to be as durable as Nikasil plating. Flat 6 Innovations and LN Engineering are doing tests to see if this will be a solid replacement for Nikasil. Time will tell.
#62
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Again, IMO purchasing a higher mileage 997 with Bore Scope Inspection performed showing clean cylinders & excellent PPI seems to be a smart approach to buying a 997 these days especially a buyer on a tight budget.
I'd buy a clean cylinder 90-110K example over a 30K-70K example all day. And money isn't an issue for me however I like peace of mind and being smart with my expenditures.
Why ****-away $25K on a rebuild when it is an easy simple process to avoid?
Just my opinion after 36 years of Porsche ownership and past 7 years of 997 S/C4S & C4 ownership.
I'd buy a clean cylinder 90-110K example over a 30K-70K example all day. And money isn't an issue for me however I like peace of mind and being smart with my expenditures.
Why ****-away $25K on a rebuild when it is an easy simple process to avoid?
Just my opinion after 36 years of Porsche ownership and past 7 years of 997 S/C4S & C4 ownership.
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Last edited by groovzilla; 11-20-2022 at 04:57 PM.
#63
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2009 C2S185K miles
It appears you are assuming all 997s are 997s. They are not. 2009 on, what is called a 997.2 with a 9A1 engine, has what appears to be a near bullet proof engine. If you are concerned, get a .2 car. I owned the previous engine and had two blow. So.... my next purchase would only be a 2009 or newer. YMMV
Peace
Bruce in Philly (now Atlanta)
It appears you are assuming all 997s are 997s. They are not. 2009 on, what is called a 997.2 with a 9A1 engine, has what appears to be a near bullet proof engine. If you are concerned, get a .2 car. I owned the previous engine and had two blow. So.... my next purchase would only be a 2009 or newer. YMMV
Peace
Bruce in Philly (now Atlanta)
After talking to a car buddy of mine I think I am close to talking myself out of a 997.1.
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- Install an LN Engineering thermostat
- Use a high quality oil
- Change the oil frequently
- Send oil samples to Blackstone for analysis & cut open the oil filter
- Make sure the car is always warm (200F oil temp) before going above 3000 RPM
- Clean out radiators
Thanks for the responses by the way.
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#64
Burning Brakes
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Good point. I think since the 9A1 based cars are now way out of warranty, they're seeing their way into the hands of DiYrs and independent shops. This will reveal more of the good, bad, and ugly with the Alusil closed deck cylinder technology. For what it's worth, SUMEbore cylinder technology in post 2019 Porsche cars is showing to be as durable as Nikasil plating. Flat 6 Innovations and LN Engineering are doing tests to see if this will be a solid replacement for Nikasil. Time will tell.
Atmospheric plasma spraying (APS)
To create a sufficiently robust iron running surface, the cylinder walls are first roughened with a special milling tool which cuts a dovetailed pattern into the cylinder. The resulting undercuts ensure that the APS coating adheres properly. A rotating plasma torch is then inserted into the cylinder. An arc discharge is used to create a plasma into which a powdered coating material is blown using compressed air. The powder melts and is sprayed onto the rough cylinder wall. There it solidifies and fills the undercuts thus creating a wear layer. A layer of iron (roughly equivalent to 100Cr6 bearing steel) is applied in several layers in approximately 30 seconds. The final thickness is approximately 150 micrometers. (One micrometer equals one millionth of a meter.)
Last edited by Ericson38; 11-20-2022 at 09:29 PM.
#65
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Same thing -- the technology is being used in several VWAG brands in newer, high end engines. SUMEBore coatings are applied by a powder-based air plasma spraying (APS) process.
#66
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The 9A1 is not bulletproof. It uses the same cylinder technology as its water cooled non-Mezger predecessors that are prone to bore scoring and there's a reason Porsche ditched it for SUMEbore coatings in the newer engines.
#67
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This is true, there have been enough anecdotal failures documented here that I wouldn't call them bulletproof. I'm starting to think warm or cold weather cars makes no difference. As these cars get miles on them, they'll make themselves known.
#68
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I wouldn’t own a 997 if it were my only car
Having owned lots of Japaneese cars and German cars, they are not the same. The build and quality of the German car is noticeably better which translates to the ride and experience. If I had one car to daily it would be an RS5. I currently have a tuned S4 and will probably go that route, although the S4 is a beast. If you want something smaller, more nibble try an RS3 or an M2, although IMO the fit and finish of the Audi is closer to a Porsche
#69
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Mercedes Sedans and SUV's are superior to Japanese. Much better suspension/steering/brakes and overall comfort but you pay for it ![Cool](https://rennlist.com/forums/images/smilies/cool.gif)
And personally our Mercedes SUV and sedan's are diesel which are great MPG and reliability.
I wouldn't use a 997 for a daily driver but I'm older at 63 and like the SUV comfort for most of my driving. Funny how I used to think my bones and muscles would never ache.
Enjoy the hunt. ...and make sure you get thorough PPI and Bore scope Inspection for peace of mind.
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And personally our Mercedes SUV and sedan's are diesel which are great MPG and reliability.
I wouldn't use a 997 for a daily driver but I'm older at 63 and like the SUV comfort for most of my driving. Funny how I used to think my bones and muscles would never ache.
Enjoy the hunt. ...and make sure you get thorough PPI and Bore scope Inspection for peace of mind.
Last edited by groovzilla; 11-20-2022 at 11:23 PM.
#70
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#71
RL Community Team
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https://myemail.constantcontact.com/...id=KpujerQy6iw
I have some documents that describe the differences in more detail.... PM me if you want some long reads.
Peace
Bruce in Philly (now Atlanta)
Last edited by Bruce In Philly; 11-21-2022 at 11:31 AM.
#72
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I am not sure of this. The M96/M97 engines (997.1) used an open deck design with Lokasil lining, and the 9A1 used a closed deck design with different liner casting call Alusil... and of course there is no IMS in the 9A1. Even the pistons, rings, and crank bearing systems, the oiling system of pumps and savaging... all are very different. The 9A1 is a very different block.
Peace
Bruce in Philly (now Atlanta)
Peace
Bruce in Philly (now Atlanta)