Next Big Mystery: When? The C8 Flatplane Crank Reveal?

[SheepDog]

We know about July 18, 2019. We know the tried and true small block push rod engine. Great. We know about the engine location. Kind of know the look.

WHEN? The flat-plane crank? What displacement? Redline? How long tested per engine units tested? 200K. 300K 500K HP? Torque? Performance projection?

Will C8 get LT4? Lt5?


We know a DOHC flat crank is being prepared . Corvette told us so! See video. Now , When is the only Mystery?

[Meldoon]

I guess if they think they can maintain reliability with a flat plane crank engine it is feasible. The prototype race car sounds awesome,but, I’m not sure that means production cars will get a flat plane crank engine. How many different engine configurations do they need? 500hp? 800hp? 800hp + 200 electric hp? Inquiring minds want to know........😎

[RoketRdr]

I guess if they think they can maintain reliability with a flat plane crank engine it is feasible. The prototype race car sounds awesome,but, I’m not sure that means production cars will get a flat plane crank engine. How many different engine configurations do they need? 500hp? 800hp? 800hp + 200 electric hp? Inquiring minds want to know........😎

According to IMSA, as well as most other race orgs, the race engine must be the same architecture as the production engine. This vid is definitely a FPC engine so either Chevy was testing a future engine for possibly the DP class or the FPC engine will be in the base Vette. Just a couple more months and we'll find out.

[Meldoon]

IMSA apparently limits Corvette engine size to 5.5 liter. So, instead of using the 6.2L LT4 with a supercharger, they use a 5.5 liter normally aspirated engine. Seems to me, removing a supercharger is a more significant change than a crankshaft change. If Pratt and Miller builds a new 5.5 liter engine, with a flat plane crank, I’m not so sure that guarantees a flat plane crank engine for the production cars. I will remain hopeful, but like the wise man said, “Don’t hold your breath, it’ll make you blue...”

[John]

In the Fall, 2017 IHS Markit Engine Forecast predicted three different motor sizes for the C8, e.g., the OHV, 16V, 6.2L motor, and the two 32V, DOHC 4.2L and 5.5L motors. Which one(s) will we get and when? Will any have have a flat plane crank? Might the customer motors remain different from the Corvette factory race car motors?

[Meldoon]

In the Fall, 2017 IHS Markit Engine Forecast predicted three different motor sizes for the C8, e.g., the OHV, 16V, 6.2L motor, and the two 32V, DOHC 4.2L and 5.5L motors. Which one(s) will we get and when? Will any have have a flat plane crank? Might the customer motors remain different from the Corvette factory race car motors?

More WILL be revealed.......

[RoketRdr]

If Pratt and Miller builds a new 5.5 liter engine, with a flat plane crank, I’m not so sure that guarantees a flat plane crank engine for the production cars. I will remain hopeful, but like the wise man said, “Don’t hold your breath, it’ll make you blue...”

Actually it would because as stated IMSA requires the race engines to share the same architecture and design with the production engines. They limit displacement and forced induction but everything else has to be the same. If the production engine has a FPC the race engine must use it as well. IMSA isn't suddenly going to change the rules for Team Corvette especially since they've been intentionally penalizing them and trying to slow them down. If they allow a deviation for the Corvette then they have to allow all other teams to do it as well and that defeats the purpose and spirit of the class.

[John]

Thanks RoketRdr. I really appreciate your post’s information!

[Meldoon]

Actually it would because as stated IMSA requires the race engines to share the same architecture and design with the production engines. They limit displacement and forced induction but everything else has to be the same. If the production engine has a FPC the race engine must use it as well. IMSA isn't suddenly going to change the rules for Team Corvette especially since they've been intentionally penalizing them and trying to slow them down. If they allow a deviation for the Corvette then they have to allow all other teams to do it as well and that defeats the purpose and spirit of the class.

I’m sure you’re right. I can’t find specific regulations about engines so I’ll have to take your word on that. As far as changing rules, or bending them, they seem to do that often enough. They let Porsche move their engine to the other side of the rear axle. They also let BMW run the M8 before it could be purchased. What with Balance of Power being applied, reliability is probably first and foremost. As you pointed out, they are already being penalized for their success.
I wonder what the current race engine would sound like with the shorter exhaust used on the mid engine car.

[JB]

I believe for a proper flat plane crank displacement can not go above 4.2 liters.

i believe fords foray with a 5.2 liter flat plane crank is too large a displacement and caused massive vibrational issues.

[P-Tree]

I believe for a proper flat plane crank displacement can not go above 4.2 liters.

i believe fords foray with a 5.2 liter flat plane crank is too large a displacement and caused massive vibrational issues.

I owned GT350. Engine was solid. You can have an FPC that large. The motor was a gem, it was just in the wrong car.

[Z_Rocks]

The motor was a gem, it was just in the wrong car.

What do you mean? What would be a more suitable car?

[P-Tree]

What do you mean? What would be a more suitable car?

A car that weighs less. GT350 Track Pack is ~3,800 lbs+- a couple hundred for driver and fluids. So full tank of gas and me in it, over 4,000 lbs. Engine makes good power, from 4k up. Because of the FPC, doesn't have the low end torque like a OHV motor does. But, you put that engine in a car that weighs 2,800 - 3,200 lbs, I would probably still have it. I wanted to fall in love, but I couldn't. It's a shame, because the engine, transmission, and suspension were all very good. It was a pig with lip stick. A pretty pig, but a pig none the less. The engine just loves to rev and rev though. Having owned that, and driven a NA V12 car before, is why I'm hoping the Zed Oh Sex is a NA FPC.

[Z_Rocks]

A car that weighs less. GT350 Track Pack is ~3,800 lbs+- a couple hundred for driver and fluids. So full tank of gas and me in it, over 4,000 lbs. Engine makes good power, from 4k up. Because of the FPC, doesn't have the low end torque like a OHV motor does. But, you put that engine in a car that weighs 2,800 - 3,200 lbs, I would probably still have it. I wanted to fall in love, but I couldn't. It's a shame, because the engine, transmission, and suspension were all very good. It was a pig with lip stick. A pretty pig, but a pig none the less. The engine just loves to rev and rev though. Having owned that, and a NA V12 car before, is why I'm hoping the Zed Oh Sex is a NA FPC.

I drove a friend's GT350 in the city (on street with limited room to rev) and noticed very low TQ in low RPM, in fact it felt worst than a Mustang GT. He eventually traded it in for a C7.

So, is the base C8 going to have FPC?

[P-Tree]

I drove a friend's GT350 in the city (on street with limited room to rev) and noticed very low TQ in low RPM, in fact it felt worst than a Mustang GT. He eventually traded it in for a C7.

So, is the base C8 going to have FPC?

Others or more in tuned with the rumor mill and inside sources than me, but everything I've seen is an updated LT1 (LT2) for the base car. OHV, maybe DOHC? But nothing saying a FPC for the base.