40th Ann. bore scoring?

Is bore scoring an issue with the 40th anniversary cars?

Bore scoring is definitely a problem on 40th Ann cars. If you are worrying that your car is having the problem get it scoped out or look for the simple signs like soot coming from the left side tail pipe.

X51 package with better oiling and cooling did try to help minimize bore scoring but there have been plenty car with reported bore scoring. Like Alex said, get it scoped. All cars will have some level of wear. You need to identify whether it's scoring or scuffing.

The 40th AE cars are no different in respect to cylinder bore scoring and IMS bearing failure than other Carreras. The X51 power package really doesn't help prevent it. The AE cars have all the variables in the equation that leads to scoring. And the 6204 IMS bearing on these cars should also be replaced with a proven oil-fed plain bearing design of the IMS Solution. I encourage you to watch Jake Raby's series on the subject. You Tube

There is no data to show that 40 AE car are more or less prone to bore scoring than any other 3.6 M96 engine. Comments otherwise are just opinions. 911user on this forum has 440,000 miles on his with a totally original engine.

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The core makeup of the M9X engine of the AE cars is no different than other M96 Carreras. I've worked with Flat 6 Innovations and LN Engineering for the past 3 years. They have documented a tremendous amount of data on these cars for the last 20+ years in respect to cylinder bore scoring. Charles Navarro just spent more than a year writing a technical article on the subject of bore scoring. You should read it. https://lnengineering.com/education/...s-navarro.html The reality is the AE cars are susceptible to cylinder bore scoring. p.s. Everyone knows about the RL member "911user" lone 400K mile 40th AE car. That just proves driving these cars is better than letting them sit as a garage queen.

The 40AE is just like any other M96.03 in regard to the short block specs.

Thanks all for the info on this. I'm not an owner but i've always been interested in these cars and wondered if the X51might have mitigated the problem. Apparently not

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We are both arguing the same point just in a different way

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I beg the differ my friend. You said that there is no data to prove that the engine in the 40AE scores more or less than any other M96 engine. I've noted Flat 6 and LN have more than 20+ years of data to show for example... The 3.6L M96.03S in the 40AE with forged pistons, piston offset, shortened rod-to-stroke ratio, lokasil II bores, etc. have shown to be MORE susceptible to cylinder bore scoring compared to an M96.22 2.7L engine with cast pistons in a 986.

At the end of the day people have a general misconception about the 40AE and other X-51 engines. They believe that the entire engine is different, and is "better" than the base Carrera. What needs to be understood is the 40AE changes start at the cylinder heads, and sump. The short block is just an M96.03, like any other. This is why you could buy the X-15 "power kit" and bolt that onto a standard base Carrera engine back in the day. The X-51 isn't magical to me. It actually takes MORE effort for us to whip the X-51 heads and other components into submission when compared to the base Carrera 3.6L heads. They are more finicky with displacement increases, and etc. We can make it work, and have been for years. @ltusler can vouch for that, and he can also vouch for how much faster his car is with my R51 CNC heads fitted, since he has had both for over a decade of track only service.

Short blocks are all same. Besides t he intake manifolds being cast aluminum, and according to the Porsche service manual the following are the differences with X51: Item 1: Pistons Item 2: Inlet camshafts and exhaust camshafts Item 3: Valve discs, valve springs, valve guides, valve seats Item 4: Valves, valve caps Item 5: Dual-chamber suction pump at cylinder bank 4 -6 Item 6: Oil suction pipe Item 7: Oil pan with partition box Item 8: Gasket for exhaust manifolds Item 9: Exhaust manifolds Item 10: Suction line on A/C compressor Item 11: Intake pipes Item 12: Intake distributors I think some people focus on item #5 as it does help with lubricating those cylinders, but clearly, scoring is and has been seen, even with this. More than anything, it will come down to the owner and how they treated the car, especially from cold. I bet you could kill and FSI motor if you don't maintain it properly, let it idle to warm up and only do short trips where the oil never gets to proper operating temperature. Reminds me of the story Lake Speed Jr. told about this.

Item 1: I disagree here. I have compared the pistons side by side and even weighed them. I have never noted a difference in the base 996 piston, and the 40AE. They can say there's a difference all day long, or even claim a different part number, but I have the pistons in hand that disproves it.

ah, interesting. Did not know that so thanks for confirming. It might be down to part numbers as a part of the package.

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...or perhaps it's the factory just trying to make the X51 sound more special.

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Kind of like the "integrated dry sump" which is just a wet sump with a fancy name. AKA "vaporware".

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Eggzackery right!

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Porsche factory spinning yarns? Possibly. But there is no doubt they spent considerable efforts on this engine design. Not just some fender badge....😎

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Last time I checked the 2.7 was never installed in a 911. I've noticed in other posts you seem to have a propensity to self aggrandize and expect that you would argue with your own shadow

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Y'all are confusing the two "different" X51 Kits, the 3.4 X51 (was not available in the US) and the 3.6 X51 Kit (used also on the 40AE). Jake is correct the 3.6 X51 has the same pistons as all other 3.6 engines. Pipete84 is correct that the 3.4 X51 DOES have different pistons, they have a slightly deeper valve relief cut in the piston top to accommodate the higher lift camshaft.

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Whoa sparky!... no need for personal attacks. This is a technical forum and we debate. There were 2.7L engines installed in past 911 cars. Check your history. Maybe you're talking about just the 996 generation? You said in your original comment and I quote, " no data to show that 40 AE car are more or less prone to bore scoring than ant other 3.6 M96 engine " That's absolutely not true. I responded clearly there IS data. Again, LN and Flat 6 have been keeping detailed records on cylinder bore scoring for more than 20+ years. You then said quote, " We are both arguing the same point just in a different way " I disagreed and gave you a quick M96 example that doesn't score. Yes, it was a 986 engine, but now you're offended and say I "self aggrandize" ??? Really? Ok then... If you want to get super specific with your first comment and just look at 911 M96 3.6L engines, then you need to look no further than the M96.70, 76, 79, 80 engines. Those engines don't score either. But your M96.03S has the same block and piston composition as other Mk2 M96.03 Carreras of the same generation and they're more prone to scoring and there is data to back it up. Do you still disagree? I get it... you have a 40AE and you're going to defend it. (beautiful cars by the way!) The same thing going on over at the 997 forum with people think the 9A1 997.2 is appreciating out of the roof. I provided hard data that they've actually depreciated some, but they don't believe it and so they'll continue thinking something that is truly not the case with the used market.

Data point of 1 - a little less than a year ago I bought a very nice 40AE with just 37k miles. Got a pretty good deal on it with a sellers guarantee that it would pass PPI. As luck would have it, the bore scoring found during PPI meant it wasn't eligible for the IMS Solution. It's not too bad yet, with no smoke, soot, tick or anything. After some consideration and a consultation with FSI I decided to keep the car. There isn't anything I don't love about my 40th, so I decided to go all in and got into Jake's queue. Looking forward to Jake "whipping the X51 heads and other components into submission" later this year.