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.

 

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!

 

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.

 

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.

 

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?

 

The most recent leak down test was at 3%, I'll pull the hours on it tomorrow

 

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%

 

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.