DebRedZR1

Doubt it. I don’t have to have been there to know what the #facts were.

ColdPIzza

Show the picture you have of the panels. I remember when you posted them at the time and they were clearly not damaged panels.

Your friend very well may have seen a mule testing, but not one that crashed. It didnt happen.

BIG Dave

How much “newer” is a DOHC? The OHV was patented by Buick in 1902, and (please correct me if I’m wrong) the DOHC first appeared in a 1912 Peugeot. They’re both over 100 year old designs! (AFAIK)

Oneslackr

You're correct. I've posted this article before about the 1912 DOHC Peugeot. For anyone that might be interersted:

http://theoldmotor.com/?p=62241

Quote from the above article:

RapidC84B

We were all waiting to get in the paddock and then all had to wait nearly 3 hours and got in around 8 pm. Something happened and they were delayed leaving. They overlooked the piece we found.

I have no tangible proof the car was a Z06. I was told the car was clearly twin turbo when testing and that it crashed late in the day hence the delayed leave. Can't say more w/o messing with my source.

ColdPIzza

Oh goodie....another reliable "friend ". Those are always the best!

The panels you posted back then because your "friend" claimed they came from said crashed car were 1) not damaged panels, and 2) not from a C8.

But have at it. Makes for a great forum story.

Quinten33

Thanks for the scoop




It’s the CT5 prototype’s fake hood scoop.

proexpert

This section is entertainment. You guys are funny.

sunsalem

It's a cost-cutting measure.

If GM did that, it would imply the C8 is a revolutionary Corvette....oh wait.

68roadster

Well some people on this forum think the base C8 is planned to take down Ferrari and cost >150,000

quick04Z06

In reality, cam-in-block engines are newer than OHC engines and they offer a number of weight and packaging advantages over DOHC engines, but the non-engineering public thinks OHC is “cooler” and “more relevant”, so from a marketing perspective, I agree with you; however, to keep the base C8 reasonably priced, using an LT engine gives great corporate economy of scale and the LT engines are strong and reliable and GM has kept them completely up-to-date technologically.

I suspect the higher-end C8s will have all the bells-and -whistles—dohc, TT, hybrid. all wheel drive, probably 4-wheel steering, low speed front lift, active aero—and will cost a lot more but will be the tech leaders GM wants them to be. But we can all buy and brag about them to our Euro sportscar friends....after we blow by them at the track. 😜

P.S. If GM really wants to throw a touchdown here, what they should do is ditch double overhead cams, 4V, and have direct pneumatic 4 valve actuation like Renault developed for F1 several years ago and put this on an ultra high-end “super” Zora. The pneumatic valve actuation enabled these engines to turn around 22,000 RPM before the FIA decided they needed to cut costs and reduce RPM range. That would be a technological bragging point that no other street car in the world has, as far as I know. Build a 10,000 rpm street engine!

ClothSeats

There are two important advantages of DOHC compared to OHV:
1. There are no pushrods with the DOHC design. This allows for straight intake and exhaust ports because they don't have to make a dogleg around the pushrods. Straight ports are better for airflow and higher RPM.
2. DOHC allows for four valves per cylinder. These valves are smaller and therefore have less mass, and can achieve higher RPM without floating. Also contributing to the reduced reciprocating valvetrain mass is no pushrods or rocker arms.

Here is another comment about OHV engines. I admire the LS7 engine because of all the power it generates without a turbocharger. The engineers really had to cramp everything into a small package with siamesed cylinders and valve seats. Those things seem to have worked, but valve breakage is an issue. Being an OHV engine, it only has two valves per cylinder, and they are huge. I have to believe that the large diameter of those valves is part of the reason for the breakage problems. Any little piece of carbon that finds itself between the valve and the seat will act to bend the valve when it closes. This is like using a lever against the valve, and all the force gets concentrated at the point where the valve joins with the valve stem. Smaller valves, such as those found in a DOHC engine, will experience far less leverage against the valve when a piece of carbon is trapped.

Supermassive

I always get a kick out of the weenies that see the LT1 and think it is somehow less advanced than DOHC engines. There is literally no tech found on DOHC engines that is not present in the LT1. The only advantage to DOHC over OHV is the creation of a high revving engine that sacrifices torque for top end HP. I am holding out for the Z06 variant to see if I will want the GS version based on looks. I want a Katech Street Attack 427 or whatever equivalent they make out of the LT2...because 700hp and 620 ftlbs of torque out of a NA engine is just about perfect. Turbos can be fun but they add weight and complexity, sure the Z06 version may make even more than 700hp but the noise that comes out of an LT1 is so much more menacing than high strung DOHC with turbos.

I mean how can anyone hate this?

PurpleLion

Better yet, implement solenoid activated valves using a 4 valve head that can be programmed to mimic any type of tune. Electric valves could be programmed for low speed, high torque operation like the current LT-1 or high speed 4 valve operation like a current Ferrari, etc.

Oneslackr

Start at the 9:00 mark to hear the car.

Jinx

The future isn't high-rpm. Maybe exotics can keep building engines that scream, for as long as their well-heeled buyers insist on them, but the industry is headed elsewhere.

Skullbussa

Not with a pushrod V8 it's not.

If you want to play with the big boys you need to develop a turbo motor that can put down 500+ to the tire, all day long (no supercharger), meets modern emissions standards, likes to freely rev, sounds good, and gets respectable fuel economy. If the motor can be shared across applications (other cars/trucks) so much the better. This was Ford's big mistake with the Voodoo engine in the GT350, it was entirely bespoke, a bit fragile due to vibration issues, but I would take one of those engines over the LS7 in my C6 Z06 ANY day of the week.

GM knows all of this which is why they're investing in that technology for the alleged C8 Z06. I can't wait to see the tuning potential of that car.

RapidC84B

C5/6/7Rs have no issue beating Ferraris with pushrods.

atterbud

Outside of a few race series in the US and Australia that intentionally limit development to reduce costs, race engines have been DOHC since the 1960's. Now some have moved on to electronically controlled pneumatically activated valves and that technology will eventually trickle into road engines (I believe Koenigsegg have patented the technology in Europe), but I doubt that the combined genius of race engine design engineers is going to have a eureka moment any time soon that they have all gone in the wrong direction this past 50 years!

Outside of the US, engine efficiency is as important as power and torque and this is where the DOHC outstrips the OHV every time.

jvp

By "efficiency" you mean specific output, which technically isn't engine efficiency. It's: specific output. :-) And you're correct in that outside of our country, specific output is far more interesting. Places such as a lot of European countries (or all of them?) where folks get taxed on engine displacement. In places like that, having a higher specific output is more useful to keep costs in check. We don't have to worry about that here in the US and are free to have engines of any size we like. What we do have to keep in mind is FE and emissions; which can be tied into displacement in some cases.

It doesn't make an OHV engine any less capable or interesting or powerful or... anything like that. I think the Corvette has, thus far, done a fantastic job of proving just that. :-)