Chevrolet to reveal C8 Corvette Z06 today at noon

I have the same non-existent use case for this as I do for the super cars it is chasing. 
 

putting on the nomex.......

heads look pretty compact for DOHC

In reply to Rigante :

No kidding, I couldn't tell it was DOHC from the pics. Had to go look at the specs. Still a small engine.

I assume there's no manual option?

In reply to codrus (Forum Supporter) :

Apparently no option for a front bumper that looks like it was designed by adults, either.

codrus (Forum Supporter) said:

I assume there's no manual option?

 

DSG.

After seeing the NVH mess of the GT350, I'm sure Chevy was adamant in not wanting a direct connection between the cabin and drivetrain.

Speaking of GT350, I also notice that the intake is set up as two four cylinder intake plenums, the way everyone else does an even firing V8, and not a single plenum, which is apparently why Ford needed the weird (for a four cylinder) crank throw arrangement.

The compactness of the valve covers makes me think it uses a cam drive like the High Feature V6, which allowed GM to have fairly small cam sprockets.  Depending on how much of the cam drive was reused, this would also introduce a commonality of parts.  The timing cover scares me from a service perspective: it's apparently also the coolant manifold.  I mean, I guess technically it is on the High Feature, too, but the grandioseness of the cover design makes me wonder if GM is (finally) introducing coolant on the exhaust sides of the engine, where the heat is.

Keith Tanner said:

In reply to Rigante :

No kidding, I couldn't tell it was DOHC from the pics. Had to go look at the specs. Still a small engine.

The cam plugs in the head weren't a dead giveaway?

In reply to Pete. (l33t FS) :

Could be like Toyota's narrow angle heads. Sprocket drives one cam and the second cam is geared to the first.

In reply to ShawnG :

Those doodads on the valve cover are VVT actuator solenoids (everyone has a different term), like a Mercedes or VW or similar.  Here's a cutaway of a Mopar 3.6.

Given the shape of the valve covers, my money's on single chain per bank driving both cams directly.  Like a High Feature.    On a low production engine like this, I bet there is a lot of "go with what you know" happening here, to minimize expense.  I don't think GM has ever made a DOHC engine where one cam was driven by the other, come to think of it.  Not that they CAN'T do it, but why change what works?

From a service perspective, I'm seeing things like bank 2 actuators failing because the oil tank is wrapped around that side of the engine, cooking them.  Actuator replacement on a Mercedes is like a half hour job.  On this, I bet step one is drop engine, so you can peel the oil tank off.

In reply to ShawnG :

Well, maybe now :) The DOHC engines I spend the most time with do not have cam plugs, but all of the variants do have very clear cam drives on the front whilst this one does not. 

Cool.

The newest engine I've played with is the one in my 2013 Escape. I'm more familiar with stuff from 70 years ago than I am with modern engines.

Looks like they kept the flat-plane stroke short enough to avoid a lot of issues.
Wonder how it was decided, computer or test engines?

Having worked with Carbon Fiber professionally (and seen the failures) I have to wonder what the MTBF is for those CF wheels?
Recommended replacement after how many miles?
I would not use them even if they were free.

Funny how GM wants it both ways, king of the hill bragging rights for ICE engineering, then abandon it all for EV's in just a few years. 

Pete. (l33t FS) said:

In reply to ShawnG :

Those doodads on the valve cover are VVT actuator solenoids (everyone has a different term), like a Mercedes or VW or similar.  Here's a cutaway of a Mopar 3.6.

Given the shape of the valve covers, my money's on single chain per bank driving both cams directly.  Like a High Feature.    On a low production engine like this, I bet there is a lot of "go with what you know" happening here, to minimize expense.  I don't think GM has ever made a DOHC engine where one cam was driven by the other, come to think of it.  Not that they CAN'T do it, but why change what works?

 

Looks like the crank is connected to a central cam (used to drive the HPFPs located in the valley), and each bank's cams are then driven from the HPFP central cam:

This is a screen grab from an animation on the official ZO6 reveal website:

*Other interesting tidbits from that site:

-the ports and combustion chambers are CNC machined

-the intake manifold has a lot going on to control/optimize airflow. The 3 valves in between the banks function differently depending on engine rpm and engine control mode:

RossD said:

GM also put the starter in the valley of a V8 once before too.

Is that still the standard bellhousing pattern?

This engine has the starter, alternator and both of the cam-driven high pressure fuel pumps in the valley.

This article has some interesting tidbits and photos of a "cutaway" display of this engine

In reply to STM317 :

Whoa Wow, that intake.

Thanks for the pics!  Lots to process in there.

The C8 styling isn't working for me. And *ducks and covers* I don't think flat-plane V8s sound as good as everyone makes them out to. I'm curious to see if this engine is less of a time bomb than the GT350 engine.

ShawnG said:

Keith Tanner said:

In reply to Rigante :

No kidding, I couldn't tell it was DOHC from the pics. Had to go look at the specs. Still a small engine.

The cam plugs in the head weren't a dead giveaway?

Those look like Cam Position Sensors.

I'm guessing that big, plastic tank on the passenger side is the dry sump oil reservoir?

akylekoz said:

In reply to STM317 :

Whoa Wow, that intake.

And you know that someone's going to put carbs on it...

Is it weird that the alternator isn't vented in any way?  How is it cooled?

ProDarwin said:

Is it weird that the alternator isn't vented in any way?  How is it cooled?

Maybe they took a page out of the BMW playbook and water cooled it?

I miss manuals.

It'll be interesting to see how this flat plane thing holds up long term.

ProDarwin said:

Is it weird that the alternator isn't vented in any way?  How is it cooled?

 

I am assuming water cooled, which is getting to be not uncommon on newer mega-amp alternators.  Practically speaking, in this car, it probably gets no meaningful airflow for the fan to move around.  An alternator fan might just recirculate the same air that it just vented.

Keith Tanner said:

akylekoz said:

In reply to STM317 :

Whoa Wow, that intake.

And you know that someone's going to put carbs on it...

I would totally dual-quad-tunnel-ram this for Tunatruck. It would probably make more power.

akylekoz said:

In reply to STM317 :

Whoa Wow, that intake.

Looks a lot like this but wirh shorter runners. I think I learned something about runner length and plenum volume and how the plenum only has to be loosely related to the trumpets