C8 Corvette

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Jolle
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Re: C8 Corvette

Post by Jolle » Sat Jul 20, 2019 7:35 pm

roon wrote:
Sat Jul 20, 2019 7:23 pm
Jolle wrote:
Sat Jul 20, 2019 7:01 pm
...the LT2 is quite high compared to what the other sports cars use. A LS2 is almost 80cm high while a modern v8 from a European constructor is below 70cm.
Are you factoring in dry sump?
Isn't the base C7 using wet sump? Defies the "we use it for a low CoG" a bit :P Also, a lot of hight comes from the air intake. There is lots of room between the heads and top of the engine, more then enough to stick a few cam shafts in and have proper breathing (and you'll would be needing a 6.2l engine to have 500ps, 4.5 should be enough) But again, this would add several thousands of dollars to the base price.

roon
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Re: C8 Corvette

Post by roon » Sat Jul 20, 2019 7:43 pm

Jolle wrote:
Sat Jul 20, 2019 7:35 pm
Isn't the base C7 using wet sump? Defies the "we use it for a low CoG" a bit
Thread is about the C8. The C8 LT2 engine is dry sumped according to Chevy's press release and presentation.

For the first time ever, the base Stingray will use an engine-mounted dry sump oil system and three scavenge pumps for improved track performance.
Image

Note the reduced height of the oil pan. Crankshaft centerline is below the rear axle.

Jolle
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Location: Dordrecht

Re: C8 Corvette

Post by Jolle » Sat Jul 20, 2019 7:52 pm

roon wrote:
Sat Jul 20, 2019 7:43 pm
Jolle wrote:
Sat Jul 20, 2019 7:35 pm
Isn't the base C7 using wet sump? Defies the "we use it for a low CoG" a bit
Thread is about the C8. The C8 LT2 engine is dry sumped according to Chevy's press release and presentation.

For the first time ever, the base Stingray will use an engine-mounted dry sump oil system and three scavenge pumps for improved track performance.
https://www.slashgear.com/wp-content/up ... 80x640.jpg
Aha, a bit of progress, together with coil springs :P

But still, there is no other advantage over a modern v8 like the Ricardo or Mercedes 4.0's other than cost. They are as light and as compact as this engine. Plus they are more fuel efficient what limits the guzzler tax.

So with a Corvette, you pay more tax :P

roon
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Re: C8 Corvette

Post by roon » Sat Jul 20, 2019 8:02 pm

Jolle wrote:
Sat Jul 20, 2019 7:52 pm
roon wrote:
Sat Jul 20, 2019 7:43 pm
Jolle wrote:
Sat Jul 20, 2019 7:35 pm
Isn't the base C7 using wet sump? Defies the "we use it for a low CoG" a bit
Thread is about the C8. The C8 LT2 engine is dry sumped according to Chevy's press release and presentation.

For the first time ever, the base Stingray will use an engine-mounted dry sump oil system and three scavenge pumps for improved track performance.
https://www.slashgear.com/wp-content/up ... 80x640.jpg
Aha, a bit of progress, together with coil springs :P

But still, there is no other advantage over a modern v8 like the Ricardo or Mercedes 4.0's other than cost. They are as light and as compact as this engine. Plus they are more fuel efficient what limits the guzzler tax.

So with a Corvette, you pay more tax :P
CoG will likely be superior even if total engine height is similar, for the reasons given. I doubt a 4L TT DOHC V8 will be as light as an 6.2L NA OHV V8. They may still export a turbocharged model. The LTA Blackwing TT V8 is manufactured in the same plant as the C8. There is a cold-vee TT powerplant in the works as well which GM supposedly confirmed was depicted in the image below.

roon wrote:
Sat Jul 20, 2019 2:55 am
Image

Maritimer
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Location: Canada

Re: C8 Corvette

Post by Maritimer » Sat Jul 20, 2019 8:11 pm

The engine in the C8.R isnt an LT2, that render is likely the race engine thatll be retuned for future Z06/ZR1 packages.

strad
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Re: C8 Corvette

Post by strad » Sun Jul 21, 2019 3:27 am

Jolle That dinosaur won at Le Mans (beating Ferrari's) a couple of times that I can remember off the top of my head along with the 24 hrs of Daytona. :wink:
Motorsport without danger is like cooking without salt
Sir Stirling Moss

roon
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Re: C8 Corvette

Post by roon » Sun Jul 21, 2019 4:36 am

Makes me wonder. Given the height, mass center advantages, would we see pushrods in F1 given the chance. Can still pull off 4v/cyl, much to the chagrin of our resident Europeans. 12k rpm? Feasible. Air springs? Applicable. Common camshaft? Doable. Given nothing fancy is being done with valve timing and duration due to the regs. 1.6L block. Small valves, tiny pushrods.

Weight of nine(?) timing gears+four camshafts vs twelve pushsticks+twelve forked rockers+one camshaft+two timing gears.
Last edited by roon on Sun Jul 21, 2019 4:46 am, edited 2 times in total.

Cold Fussion
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Re: C8 Corvette

Post by Cold Fussion » Sun Jul 21, 2019 4:43 am

strad wrote:
Sun Jul 21, 2019 3:27 am
Jolle That dinosaur won at Le Mans (beating Ferrari's) a couple of times that I can remember off the top of my head along with the 24 hrs of Daytona. :wink:
Anything can win the GT class with the right balance of performance.

Tommy Cookers
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Re: C8 Corvette

Post by Tommy Cookers » Sun Jul 21, 2019 8:45 am

Detroit pushrod design gives canted valves
(invented by accident)
kept it going the last 50 years
got the small block doing the work of a big block

Jolle
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Re: C8 Corvette

Post by Jolle » Sun Jul 21, 2019 9:22 am

roon wrote:
Sun Jul 21, 2019 4:36 am
Makes me wonder. Given the height, mass center advantages, would we see pushrods in F1 given the chance. Can still pull off 4v/cyl, much to the chagrin of our resident Europeans. 12k rpm? Feasible. Air springs? Applicable. Common camshaft? Doable. Given nothing fancy is being done with valve timing and duration due to the regs. 1.6L block. Small valves, tiny pushrods.

Weight of nine(?) timing gears+four camshafts vs twelve pushsticks+twelve forked rockers+one camshaft+two timing gears.
No, not a chance.

Look, I see why you guys love the corvette. It looks like a proper sports car and drives like you own the world. And that for a good bang for the buck. But that buck had to be saved in multiple places. The frame is steel instead of aluminium, the body plastic instead of carbon, etc etc. The engine is dirt cheap.

There was a Dutch football player who had an interesting saying: every disadvantage has its advantage.

If a pushrod engine made any sense in a car, or a sports car, there would be others. In Europe at least, the last pushrod in production was the Rover V8 that was based on an American block, it finally was fased out in the early nineties. Every car, from dirt cheap, high tech, from tractor to F1 car ditched pushrod engines. Even Chevy.

So, everybody including GM got it wrong and the LT2 engineers came up with this amazing tech that will change how we look at engines (again) or its just perfect to push it in a certain price point.

“But it won Indy with Mercedes”. Yeah... because they could use a larger capacity.

Maritimer
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Location: Canada

Re: C8 Corvette

Post by Maritimer » Sun Jul 21, 2019 4:56 pm

Pushrods would absolutely work in these motors, overhead cams are only better if you need variable lift/timing or crazy high revs. That's really it. Pushrods can go over 12k with good springs and rods, have outstanding valve lift and major packaging advantages. The heads on the current engines are the same size as the block, you could make a pushrod hemi that would be smaller and flow just as well.

e36jon
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Re: C8 Corvette

Post by e36jon » Sun Jul 21, 2019 5:33 pm

Greetings all

I have my own biases as I currently drive an e36 BMW with dual overhead cams and 4V per cylinder. That said, the most popular engine swap for my car is a small block Chevy, which is lighter, makes a ton more everything, etc...

Here's a really great technical article comparing F1 V8's to NASCAR V8's: http://www.epi-eng.com/piston_engine_te ... _to_f1.htm

I would also point folks at various C7 motor articles looking at the titanium rods and valves of the last mill. Very very trick, and capable of 8k rpm! (My BMW redlines at 6,500 rpm!)

Cheers,

Jon

roon
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Re: C8 Corvette

Post by roon » Sun Jul 21, 2019 6:52 pm

Jolle wrote:
Sun Jul 21, 2019 9:22 am
Look, I see why you guys love the corvette.
I actually don't care much for it. The arguments in this thread seem to defy physics. Thats why I'm responding to them. As is common in this forum, correction is misconstrued as opposition.

Jolle wrote:
Sun Jul 21, 2019 9:22 am
The frame is steel instead of aluminium, the body plastic instead of carbon, etc etc.
The chassis is aluminum. The bodypanels are FRP like most modern automobiles bumpers. The rear crash structure is CF.

Jolle wrote:
Sun Jul 21, 2019 9:22 am
If a pushrod engine made any sense in a car, or a sports car, there would be others. Every car, from dirt cheap, high tech, from tractor to F1 car ditched pushrod engines. Even Chevy.
Camaro still uses one, as do 100s of 1000s of trucks, if not millions. Ford unveiled a new 7.3L pushrod V8 earlier this year.

strad
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Re: C8 Corvette

Post by strad » Sun Jul 21, 2019 7:39 pm

Thanks Roon you beat me to it.
Motorsport without danger is like cooking without salt
Sir Stirling Moss

Tim.Wright
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Re: C8 Corvette

Post by Tim.Wright » Mon Jul 22, 2019 6:29 pm

roon wrote:
Sun Jul 21, 2019 6:52 pm
Jolle wrote:
Sun Jul 21, 2019 9:22 am
The frame is steel instead of aluminium, the body plastic instead of carbon, etc etc.
The chassis is aluminum. The bodypanels are FRP like most modern automobiles bumpers. The rear crash structure is CF.
Looks like an aluminium spaceframe with cast engine and suspension mountings. Similar to what Ferrari are doing.
Not the engineer at Force India