jumper5836

DFI has also been used in the Cayenne engine since 2007, they for the most part are high mileage daily drivers that see more use then any sports car will ever see. Never heard of any issues with carbon built up on them. IMO 9A1 DFI engine is a safe bet.

BGB Motorsports

I will throw out the additional data point that after the 24 Hour we put a motor in the car that had been in 2 other prior conversions and then proceeded to run an entire season on it putting the time clock somewhere around 130 hours before we yanked it and retired it. The best part was that after all that abuse and any number of excessive downshifts, despite being revved to 8125 RPM the thing still made 399.8 RWHP on the dyno showing no signs of age. We wanted to pull it apart to study it but needed the core value return so it got returned to the factory. When i told the reps from Porsche Motorsport the hours on it they looked at me like i was some sort of Ginger Headed Italian.

MileHigh911

Agreed Joe!! Wait until all cars are electric...... then, like we all miss checking a dipstick, we will all miss the idiosyncrasies of the internal combustion engine. The sky is not falling, and with every new government regulation, new problems come about. To me, this just means that part of the maintenance schedule for my GT3 is to drive it hot and fast.......but maybe still shift at 8600

A418t81

Compared to the Mezger, the 9A1 has Toyota levels of reliability. I've spent $15k in preventative maintence and repairs on my Mezger powered turbo in the past two years. I just got the car back a week ago after the infamous intake cam sleeve slip. I love the motor and it has tons of character, but I feel the 9A1 in my GT3 is equally entertaining and it's a hell of a lot less to worry with as well.

FLT6SPD

You can not "compare" your modified 997 turbo motor and reliability, trying to "break records" with bolt ons of course you are going to have reliability issues. With that said I had a massaged 997turbo EVT775 for a few years and did not have one issue, maybe it was an engineered program, or maybe I got lucky?

All of the 9A1 and Mezger GT1 block owners have there panties pretty tight and feel the need to deflect and defend there purchase. I for one am skipping the 991 all together and waiting until it trims back down to 997 levels. If I want a luxo interior I'll go for the panamera.

Drifting

Can John or someone else comment on how this cleaning would take place on a GT3 engine?

Would it be the walnut thing, or some other technique?

A418t81

This is hilarious coming from you. I've not been on the GT3 forums long, but you immediately stuck out as the biggest Mezger apologist I've come across.

My 997 has had NOTHING break as a result of the power I'm making. The coolant pipe issue is well documented. I also converted the plastic pipe connections that split under the intake manifold to the metal sharkwerks ones as well. The intake cam sleeve issue is also completely unrelated to power production and happens on stock cars mostly. This is an up and coming common failure with a $6k price tag. Finally, Porsche has used the same sh!tty power assisted slave and accumulator setup for 10 years on the 996 and 997 with a design that is guaranteed to fail, with no new design to fix the incredibly common failure points here.

The Mezger is a fun motor, but it's no more fun than the 9A1 is in the GT3, and has many design flaws that cost quite a bit of money to repair or correct preemptively. It's just that simple. I own and love both, you have a chip on your shoulder and your bias is blinding.

CYKBC

Something to consider for long-term ownership scenarios - I know Toyota, well known with their infatuation with quality/reliability/durability in the industry, offer up direct + port injection to greatly reduce (nigh eliminate) risk of carbon build-up in some of their higher powered engines.

FLT6SPD

You sir are an expert

Lets not delve into personal attacks, it gets you know where.

jumper5836

The 997 Turbo and 997 GT3 Mezger engine are different, the turbo as you pointed out has a pressed on sleeve unlike the older out going model turbo's mezger and the 997 turbo got all the plastic coolant couplers that will crack. Also 997 GT3 doesn't have assisted clutch and the turbos slave and accumulator are actually the same as the 993 turbo. The 997 turbo mezger is a mixed bag of cost saving measures.

A418t81

I apologize, my post came off a bit more harsh than I had intended, but my point still stands. Yes, I feel like I know my way around a turbo Mezger very well given how much I've pushed the stock turbo platform along. I'm extremely familiar with all the intricacies of it, right down to how hard they are to time back up correctly after a cam replacement (don't ask lol).

997s07

The GT1 Mezger is a legendary engine. That engine has gone through many iterations from as far, and if not further back, as the 964. Let's see how many Porsche lovers in the future, say 30 years, down the line singing the praises and using the 9A1.

The above said, there is no denying that the Mezger needs to be replaced. So far the 9A1 has been substituting well. The coking is a serious issue, but as long as there are remedies we are OK. I love how free revving my 9A1 is, it's a fun engine. I love my Mezger also, rock solid, race car sounding, pure viciousness.

I don't understand how or why some here place their personal identities on cars and engines. None of us designed either engine. We paid for them.

997rs4.0

This^

Won't be any fun when we only have electric engines to complain about. Enjoy these dinosaurs gentlemen.

Manifold

+1

Our passion for these expensive toys is understandable, but probably best to not let it cause us to merge our identities with them.

Alan C.

I guess I'll take that For Sale sign out of my car.