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We have 100+ 991.2 RSes in circulation here, in a catchment market of 7mm population. I haven't heard of a SINGLE engine failure vs. a handful of issues in the .1 RS
That said if this were to happen to me, I would consider it mensch of the regional Porsche organization to replace with new engine and offer extended powertrain warranty. For myself I don't have grounds to claim anything beyond that. It's one thing to maximize, but there's also what's reasonable.
I think you are being unreasonable; they replaced the engine and gave you $3.5K to cover for car being out of circulation, what else do you want?
Can you prove that you allowed the engine to warm up over 150F oil before going over 3-4rpm routinelly?
They're supposed to take your word that the car wasn't abused somehow?
2-year warranty extension is not enough?
If you lost confidence then sell car and move on...
I think you are being a bit unreasonable, they've taken care of you nicely in my humble opinion...
Thanks for the kind words. I struggle with cars that are more restoration projects than driving experience... but there's also an element of sour grapes too, since I haven't landed a longnose yet haha!
I thought I would jump in here and give my perspective on the issues. I base this entirely on what I have seen 'inside" both the 991.1 and 991.2 engines.
There are two mechanical issues the 991.2 engine suffers from. The lash cap and the block itself. The lash cap coming out of the retainer and the block twisting and causing the main bearing clearance to go away. Seen both and fixing both as I write this.
There was a drawing posted here of the valve train, but that is the 991.1 valve train with hydraulic finger operation. This was redesigned as a solid operation by us, but Porsche gave everyone the extended warranty. We will have to wait for the warranty term to expire and hopefully our fix will come back into play.
A little background on the 991.1 issue. The fingers are pushed hard into the camshaft removing any lash. You need lash to allow oil to penetrate the gap which removes the heat from the finger and the camshaft. Adding to this there was only one spray bar at the bottom of the head and the intake fingers received no oil, to even give them a chance.
The .2 engine went solid fingers. I was told that Porsche 'told" the few that were present at PCNA that they did this to make the engine more racy. Believe that or not, that was not the reason. The reason was to add the clearance back into the design. Marketing taking over the company line here.
The .1 operation been hydraulic probably helps the lash cap issue as they are the same design, lash pad in retainer. It probably dampens the whole operation. The .2 now solid, give the valve train a "solid bounce" and out pops the lash pad. The lash pad is not captured in the retainer. It just sits in the retainer. I will post some photos of this later. I have a re design of the retainer and pad underway and this will be available through ourselves and our partner, Dundon MS. This is a proven design that is used in current motorsport.
I often think, how does this happen? My thinking is, the engine designer tasked with the valve train had no idea how quickly the programmer would make the shifts. Once this was found to be a problem, all parties had moved on to new designs and the problem left to the warranty dept. Add in, the company probably decided there would be no further money spent on a fix.
Fixing problems is a huge part of our business. We are tasked to "hotrod" engines and in the process have to address the inherent issues these engines have.
Let me get some photo's taken of the parts in question here and I will post ASAP. I hope this brings some further info to the issue.
I thought I would jump in here and give my perspective on the issues. I base this entirely on what I have seen 'inside" both the 991.1 and 991.2 engines.
There are two mechanical issues the 991.2 engine suffers from. The lash cap and the block itself. The lash cap coming out of the retainer and the block twisting and causing the main bearing clearance to go away. Seen both and fixing both as I write this.
There was a drawing posted here of the valve train, but that is the 991.1 valve train with hydraulic finger operation. This was redesigned as a solid operation by us, but Porsche gave everyone the extended warranty. We will have to wait for the warranty term to expire and hopefully our fix will come back into play.
A little background on the 991.1 issue. The fingers are pushed hard into the camshaft removing any lash. You need lash to allow oil to penetrate the gap which removes the heat from the finger and the camshaft. Adding to this there was only one spray bar at the bottom of the head and the intake fingers received no oil, to even give them a chance.
The .2 engine went solid fingers. I was told that Porsche 'told" the few that were present at PCNA that they did this to make the engine more racy. Believe that or not, that was not the reason. The reason was to add the clearance back into the design. Marketing taking over the company line here.
The .1 operation been hydraulic probably helps the lash cap issue as they are the same design, lash pad in retainer. It probably dampens the whole operation. The .2 now solid, give the valve train a "solid bounce" and out pops the lash pad. The lash pad is not captured in the retainer. It just sits in the retainer. I will post some photos of this later. I have a re design of the retainer and pad underway and this will be available through ourselves and our partner, Dundon MS. This is a proven design that is used in current motorsport.
I often think, how does this happen? My thinking is, the engine designer tasked with the valve train had no idea how quickly the programmer would make the shifts. Once this was found to be a problem, all parties had moved on to new designs and the problem left to the warranty dept. Add in, the company probably decided there would be no further money spent on a fix.
Fixing problems is a huge part of our business. We are tasked to "hotrod" engines and in the process have to address the inherent issues these engines have.
Let me get some photo's taken of the parts in question here and I will post ASAP. I hope this brings some further info to the issue.
Extremely informative. Thank you for the thoughtful detailed analysis. I know of obv mine and some other failures but thus far it has been difficult to size the magnitude of the issue with the 2.RS. Looking forward to learning more.
As promised, here are some photo's of the 991.2 finger assy and Retainer with Lash pad. 991.2 mechanical 'solid" finger follower assy 991.2 Retainer and lash pad 991.2 Retainer and lash pad showing how it fits into retainer. 991.1 "solid" finger conversion we did . Shows the difference between the 991.2 and our mechanical fingers. We didn't have the luxury of starting from scratch.
I mentioned the two failures we have seen with this engine. Here is the most alarming one. This failure has repeated itself exactly the same in other engines we have apart. The two rear mains have failed but the other more forward ones have no faults other than the trash picked up. This was a failure we could not understand until we line bored the block and cleaned up all of the debris. Notice the crack all the way from the housing bore to the rear seal vent hole. This side of the block is moving enough to lose the clearance on the rear bearing shells and enough to crack the block. Stiffening is under way on our blocks along with the repair to the housing bores. There are no oversize bearing shells available, so we had to improvise with another bearing shell.
I post this info and photo's not to scare but to educate those with these cars, these are the failures we are seeing. I understand when engines fail, no one including the Porsche tech know the result. Maybe these photos will give people an idea of what is happening, when these engines fail.
I thought I would jump in here and give my perspective on the issues. I base this entirely on what I have seen 'inside" both the 991.1 and 991.2 engines.
There are two mechanical issues the 991.2 engine suffers from. The lash cap and the block itself. The lash cap coming out of the retainer and the block twisting and causing the main bearing clearance to go away. Seen both and fixing both as I write this.
There was a drawing posted here of the valve train, but that is the 991.1 valve train with hydraulic finger operation. This was redesigned as a solid operation by us, but Porsche gave everyone the extended warranty. We will have to wait for the warranty term to expire and hopefully our fix will come back into play.
A little background on the 991.1 issue. The fingers are pushed hard into the camshaft removing any lash. You need lash to allow oil to penetrate the gap which removes the heat from the finger and the camshaft. Adding to this there was only one spray bar at the bottom of the head and the intake fingers received no oil, to even give them a chance.
The .2 engine went solid fingers. I was told that Porsche 'told" the few that were present at PCNA that they did this to make the engine more racy. Believe that or not, that was not the reason. The reason was to add the clearance back into the design. Marketing taking over the company line here.
The .1 operation been hydraulic probably helps the lash cap issue as they are the same design, lash pad in retainer. It probably dampens the whole operation. The .2 now solid, give the valve train a "solid bounce" and out pops the lash pad. The lash pad is not captured in the retainer. It just sits in the retainer. I will post some photos of this later. I have a re design of the retainer and pad underway and this will be available through ourselves and our partner, Dundon MS. This is a proven design that is used in current motorsport.
I often think, how does this happen? My thinking is, the engine designer tasked with the valve train had no idea how quickly the programmer would make the shifts. Once this was found to be a problem, all parties had moved on to new designs and the problem left to the warranty dept. Add in, the company probably decided there would be no further money spent on a fix.
Fixing problems is a huge part of our business. We are tasked to "hotrod" engines and in the process have to address the inherent issues these engines have.
Let me get some photo's taken of the parts in question here and I will post ASAP. I hope this brings some further info to the issue.
Thanks for the explanation. As you state one cause of the failure is the faster shifts with the PDK. Is the lash cap issue something would also impact manual transmission cars (non-RS of course) as the engines are practically the same. I would assume the type of transmission is irrelevant to the block twisting issue.
I post this info and photo's not to scare but to educate those with these cars, these are the failures we are seeing. I understand when engines fail, no one including the Porsche tech know the result. Maybe these photos will give people an idea of what is happening, when these engines fail.
Would a 991.2 non RS GT3 suffer from this as well? My understanding is they are the same engines
Is there anything the driver can do to reduce the strain that causes this?
03-08-2021, 11:07 AM
