RapidC84B

On one hand I'd like to think the engineers tested it to near perfection. You read some of the abuse testing they do in "All Corvettes Are Red" and it's impressive. But then you look at recent history:

1. 2001 Z06s drinking oil a quart every 800 miles because they got the ring package wrong.
2. LS7s with their valvetrain geometry and valve guide issues.
3. The entire LT4 cooling system debacle

I will say the C8 LT2 is quite bulletproof and the Tremec DCT has been a very solid first go (despite what you read on social media).

Werfs Flammen

I keep seeing people on here talk about the FPC having an issue over 4L but I have failed to find any documentation to back this up. If someone could provide it I would enjoy reading up on this more. Hell we see the I5 in Audi's and that is naturally a very unbalanced design. Thanks in advance for any insight

international blue

I don’t want to get into the math….. but here are some words on it… Flat Plane Crank vs. Flat Plain Crank might be another discussion.


https://www.linkedin.com/pulse/flat-plane-silliness-how-crankshaft-press-release-duped-stephen-kim

https://www.whichcar.com.au/features...ines-explained

https://www.maintenance.org/fileSend...Vibrations.pdf

khartford

GM has not tested the flat "plain" engine because they haven't made one. They have, however, extensively tested the flat "plane" engine.

Racer X

The first link and third link actually direct to the same article about ship engines. I copy and pasted the shown URL for the first link and it is about a 3000 HP 10.000 CPC Ford engine. Showing of course you can get very high RPM from a CPC.

vndkshn

My brother's Toyota truck and SUV would like a word with you....
I've seen and been involved with SBCs revving north of 11k. Definitely possible with the right setup. Hell, I had a 383 that would turn north of 8k although I never took it there in the car. It saw 8k+ a few times in the dyno. Engine had something like 50k miles on it when I sold the car.

ZRacerLE

Corvette sales with plain engines are abysmal.

thill444

Chevy cashier "Sir, are you ready to place your order?"
Me"Yes, I would like one C8 Z06 please, but just want it plain"

CPhelps

You can test forever and never find issues that aren't there. The LS7 had a run of production issues with valve guide concentricity that caused poor rocker geometry and put excessive side load on the valves, so they increased wear between the valve stem and guides. If the pre-production parts were actually made to print, then no amount of testing is going to find the issues with non-conforming machined heads.

1. Is valid, tough to argue that one.
2. See above, my understanding of the LS7 geometry and guide issues were from non-conforming material. Still a failure from a quality perspective of not finding and still using non-conforming material, or possibly doing some ill-fated internal justification that using the non-conforming parts would be okay, but not a design issue, exactly.
3. This one is a case of the design meeting the internal requirements, but the internal requirements not being sufficient/ideal for the real world use case. GM had tested previous generation Corvettes run continuously on track up to 86F, and the C7 Z06 supposedly passed this testing. GM then realized they should raise that limit to 100F. The way it passed is also not great for the customer since it pulled timing to protect itself. Certainly better than blowing up on track, but ideally they would be able to pass the track metric without a big performance fall off like pulling massive timing would do. I know 2017+ got better and some tracks/locations/driving styles had better and worse luck than others.

That said all these issues do come back to GM being responsible as the systems integrator, quality system manager, design and manufacturer, so there's nothing to say future Vettes would be immune from similar issues, even if they aren't strictly design.

RapidC84B

I've never owned a LS7 so I'm admittedly not 100% up to speed on what actually happened. I recall them admitting that there was "bad machining" on a batch of heads in 2011, but that didn't cover all the other cars. I don't think they ever offered a reason for those cars having excessive guide wear. Best I understand is that the offset rocker arm design side loads the valve causing the material to prematurely wear and then the valve breaks and destroys the motor.

I don't buy that answer on the LT4 for a second... the entire C7 program was done on a limited budget and they just ran out of development money/time to fix it. They blamed the silly 86 degree thing. As an instructor at VIR I've been in a handful of these cars overheated with novice drivers on a warm day and advanced drivers on a normal day. A track buddy bought a 2019 manual Z07 and had it in limp mode in 15 minutes in a hot day at VIR.

UnhandledException

I own a GT350. 72,500 miles (not a typo). It drinks oil. 1 qt per 1,000 miles (since day 1, 5.5 years ago). It has piston slap. It has typewriter tick. It has a decent amount of NVH. BUT. I like it! It has a unique character. So much valve train noise. Mechanical noise. None of that muscle V8. Problem I always had with my C7 ZR1 is I cant hear the engine. Its all exhaust. Try taking a ride with me in my GT350 or GT3RS (more mechanical noise). You'll be amazed in how enjoyable they are. I never listen radio/spotify in my GT3.

GrandSport 2017

thill444

I have a friend who had a 2015 Z06 and his car will pull timing and heat soak on spirited back road runs, and it rarely gets over 90 degrees here even in the summer. GM clearly recognized there was an issue and tried to resolve this for future models, but to the best of my knowledge they left the early adopters hanging. That is my #1 fear with the C8 Z06. There being an issue with early model year and GM resolves it year 2+ and leaves early adopters out in the cold.

Cyclon36

Gets home, opens the trunk, still finds mayo all over it.

MitchAlsup

Ferrari never had problems {308, 328, 348, F355, 360, 430, 458} but 308-360 were all from the same block architecture, and 430 and 458 were also from the same block architecture. The Maserati was from the 430-458 block architecture with a cross plane crank.

We are standing (sitting) around wondering whether GM has learned from the Ford "episode" !?!?

But perhaps, magneto-resistive engine mounts will come to the rescue.

RedLS6

Plain crazy.

All of Ford's problems started when the execs heard the engine, brought the project back from the verge of cancellation on technical issues, and told the team to find a way to make it work with what they had. Plain and simple.

mirage2991

They tested the LS7 and, we know the rest.

PCMIII

So the stuck thottles that accelerated Toyotas and Lexus out of control never happened? OK then.

SharkDiverZ06

There is a REALLY easy way to avoid buying a first year Z06. Plenty of guys have all sorts of anecdotal stories on how their first model year cars were great cars, but it's all probabilities...Just know that us 2nd year and later buyers really appreciate all you early adopters volunteering for that final phase of product development testing.

PacerX

Neither did Tacoma frames rusting themselves to fracture...

Tundra frames being made out of wet noodles...

Oil sludge locking up engines...

Tailgates failing if a reasonably sized man stands on them...

Nope. None of that ever happened.