C5Driver

johnglenntwo

At least give us that 3,600lb ATS V8 4.2TT!
This is a Corvette site, and it takes something more than your status quo run of mill sled to excite us!

sunsalem

Nysschen said this because it's likely true.
Corvette will get the 5+L version.

JoesC5

The bore centers can not be changed, so what will be the bore diameter and the length of the crankshaft stroke of 5+L version of the Caddy 4.2L engine that you believe will be in the ME Corvette.

TRT SR

Well, Tadge said no mid engine vette and now this....maybe there won't be and this car we have been seeing is going to be a Cadillac exclusive

Chicago1

I keep thinking that. Seems caddy wants to break away and do its own thing and be the Halo brand. I think alot of people are going to be dissapointed when they finally releas it.

ByByBMW

The further we go into the rumors, the less I think we know. At least it seems that way with the hundreds, if not thousands of guesses, speculations, linked articles, pictures and hearsay that are getting posted.
While I understand that's what the C8 section is all about, it's dizzying how much hoopla is being published.
My speculation? The camo'd car we have seen pictures of will be the Caddy ME with the 4.2L TT. You heard it here first.

C7pimp

You're not the first to say this, and you're wrong.

Cadillac may do a ME, who knows? But what we see is for the Corvette brand. I can guarantee it.

ByByBMW

Darn it, I tried.

And how do we know you know?

johnglenntwo

Corvette Racing was more successful than Cadillac, but, they have only been winning half as much with the C7R....SLATED!

JerryC5

There is a lot of hype, but that's the way to bolster sales. I'm happy Cadillac is getting a performance engine, and I know that when the C8 gets released, I will be ordering one, no matter which engine it has.

johnglenntwo

It has pissed-off the competition! ME, and OHV (CoG/RPM's, moving parts; cheaper to try)!

Speednet

Because he's seen the real thing. C7P already said in the render threads that he has seen two photos of the car in all its glory (not camouflaged).

C5Driver

Folks lets remember that red painted front clip in the plant paint shop. I don't see ANY Cadillac at all in its design. Im guessing we will see two cars off of that mid engine platform to help cut costs and losses in case its a flop.

Jinx

This is a good point.

The LS7 had 111.76mm bore spacing and 104.775mm bore diameter.
The LTA has 96mm bore spacing and 86mm bore diameter.

If you pushed the LTA cylinders as close together as the LS7 cylinders, you could get a 92.985mm bore diameter, which at the same 90.2mm stroke as the LTA is exactly 4.9L displacement. If you could square it up you'd get just over 5L.

I expect if GM wants a DOHC engine to fill the LT4 slot they might use common design principles but nothing else from the LTA.

JoesC5

The LS7 wasn't built for 20 PSI boost, so decreasing the land from the LTA's .390" to the LS7's .275" is not feasible.

The LT5(4.060" X 3.625" and 4.4" bore centers) is built for boost(and less than 20 pounds, actually 9.71 psi) and has a .340" land between the cylinders.

The 4.2L Caddy engine has 3.39" bore and a 3.55" stroke and 3.78" bore centers(with a .390" land between centers).

Boring the 4.2L is out of the question with 20 pounds of boost.

That leaves increasing the stroke. To get 5.5L of displacement with a 3.39" bore would require a 4.609" stroke.

4.609" stroke is crazy talk. The deck height would have to be raised, making the engine taller, and making the deck height taller would not be using the LTA block, etc.

If they did bore the 4.2L 3.39" out .050" to 3.44" to have the same land as the LT5, it would still take a 4.476 " stroke to achieve a 5.5 liter displacement and a 4.476" stroke is still crazy talk. And those thinner cylinder walls might not take to kindly to 20 pounds of boost.

The 4.2L LTA engine was designed around getting the most efficient use of packaging thus they made the block much smaller than the LT5 block.

If GM plans to have a 5.5L DOHC engine, then they would probably use a 6.2L block(but not a LT1 block) so they can use the existing transfer lines, etc for the machining etc, with a slightly smaller bore or possible a slightly shorter stoke or a combination of the two. I would bet they would go with a slightly smaller bore, thus increasing the thickness of the iron liners, making high boost more practical. Using the same stroke of the present 6.2L engine, but with a slightly smaller bore, would allow them to use the crankshaft and rods out of the LT5's parts bin. I really doubt they would come out with a new block with slightly less bore centers just to drop down to 5.5 liters displacement from 6.2L.

As a side note, the Northstar engine in the XLR was 4.6L and they decreased the bore .080", to increase the land for improved head gasket sealing, and to increase the wall thickness for improved strength with the 4.4L XLR-V(supercharged) engine. And the XLR-V had nowhere near 20 pounds of boost(actually it had 12 psi boost). The Northstar had a 4.00" bore spacing(.220" more than the 4.2L LTA engine) and it was reported to be able to be opened up to 5.4L(but never was in a production vehicle)

JerriVette

Go Tom 57.42 for some insights on the corvette c8 and the Cadillac motor

http://www.autoline.tv/journal/?cat=1513

Bikerjulio

I liked the comments in general, especially on the base price. IDK if my salesman has any special insight, but he said exactly the same thing (number), to me a month or more ago.

jma242

That camo car is definitely the C8 IMO.

Modern Corvettes have been benched by GM against Porsche for awhile now. Usually the 911. That is their primary competition in the US market. This mid-engine camo cars have been photographed with a red Turbo S.

I have a feeling we are going to see a C8 model to compete with the various models Porsche offers, from the 718 all the way up to the Turbo models.

JerriVette

The 718 is a four cylinder...