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991.2 engine rebuild questions

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Old Mar 29, 2024 | 04:02 PM
  #16  
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991.2 engine can be rebuild only once according to Porsche.

The 4.0 liter DFi engine does not have replaceable cylinders, like the 991.1 Mezger based engine.
The new engines have Nikasil coated cylinders fixed in the crank case. This should last for 200 hours.
Most likely more, but that is what Porsche recommends. Porsche also does not sell the cranckcase as separate part.

I hope, now most of the 991.2 Cup engines are past their 1st rebuild period,
engine shops will find solutions to rebuild these for a 2nd time.




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Old Mar 29, 2024 | 05:43 PM
  #17  
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Originally Posted by 93 FireHawk 968
150-200hours? Holy crap! Talk about playing with fire.
it is interesting...As his car is looked over by a competent shop. Compression checks GREAT...And car makes good power.

At that point...Might as well buy used motors...And save money!
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Old Mar 29, 2024 | 07:28 PM
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I’ve seen some solutions for Alusil coated cylinder refresh in the Audi/BMW world. I suspect similar will work on the .2’s? I know there’s a shop by VIR working with that but he woulda rebuilds BMW S62 and S54 engines. Maybe a niche market here for him to purely handle the coating for PCar shops to handle the rest of the rebuild.

Last edited by Daytona4RS; Mar 29, 2024 at 07:33 PM.
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Old Mar 29, 2024 | 07:54 PM
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Actually after a quick chat with the builder, nope. Nikasil is more of a coating and not an alloy. So no way to bring it back into spec. Guess just sleeving will be the only option.
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Old Mar 29, 2024 | 10:54 PM
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There are a few platers in the US that offer Nikasil plating, and have been plating other Porsche engines for some years. US Chrome is one. Block is plated and then honed to original cylinder specs. All ferrous parts need to be removed for the plating process, maybe that is not possible on the 991.2 blocks?

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Old Apr 6, 2024 | 03:58 AM
  #21  
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Originally Posted by zracer196
it is interesting...As his car is looked over by a competent shop. Compression checks GREAT...And car makes good power.

At that point...Might as well buy used motors...And save money!

The most recent leak down test was at 3%, I'll pull the hours on it tomorrow
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Old Apr 6, 2024 | 04:26 AM
  #22  
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think weakest link in the 991.2 engines is the oil distribution and oil pump.
this is hard to measure and is usually terminal from one moment to the other, without any pre-notice.
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Old Apr 6, 2024 | 11:00 AM
  #23  
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Originally Posted by Q&A
think weakest link in the 991.2 engines is the oil distribution and oil pump.
this is hard to measure and is usually terminal from one moment to the other, without any pre-notice.
^ this 100%
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Old Apr 6, 2024 | 01:59 PM
  #24  
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I remember some club racing/DE guys with 996/997 cups dropping the peak RPM by 2-300 and extending the life of the motor fairly significantly. Not sure if that applies to the 991/992s but wouldn't be surprised if people started to do it.
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Old Mar 5, 2026 | 07:48 PM
  #25  
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Has this advanced now we see more 991.2 cups in private hands?
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Old Mar 6, 2026 | 02:03 AM
  #26  
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Originally Posted by Williamsf1
Has this advanced now we see more 991.2 cups in private hands?
got it up to 290 hrs without a rebuild, never touched the engine. Just regular maintenance


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Old Mar 6, 2026 | 10:02 PM
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Super impressive what oil changes can do!

are you dropping both gear and engine oil every 3 track days?
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Old Mar 7, 2026 | 11:58 AM
  #28  
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Originally Posted by C4SGRPDK
got it up to 290 hrs without a rebuild, never touched the engine. Just regular maintenance

the goat
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Old Mar 7, 2026 | 11:16 PM
  #29  
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Default 997.2 Cup costs/

@Racecarsforyou would you happen to
have the costs for 997.2 Cups?
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Old Mar 11, 2026 | 05:31 PM
  #30  
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Originally Posted by Williamsf1
Super impressive what oil changes can do!

are you dropping both gear and engine oil every 3 track days?
I change the gearbox oil after every event (2-3 days) and engine oil every 2-6 days

using motul 300v 15-50 since new
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