New gen v small block lt1

[Michael J.]

Re: New gen v small block lt1

Duke, don't you find it odd they are just dumping the LS7 and LS9 engines for this one? I could see replacing the LS3, but it too is not that old or antiquated, but why dump those high performance engines with nothing to replace it with for perhaps many years?

[Terry M.]

Re: New gen v small block lt1

Duke, don't you find it odd they are just dumping the LS7 and LS9 engines for this one? I could see replacing the LS3, but it too is not that old or antiquated, but why dump those high performance engines with nothing to replace it with for perhaps many years?

My guess: CAFE

[Duke W.]

Re: New gen v small block lt1

Since the new LT1 is a complete redesign despite not looking that much different on the outside from the LS, all new tooling will be required, and it's not practical to keep manufacturing the old design alongside the new design. For one thing they don't have the space, and this new more fuel-efficient engine is required to meet near term truck CAFE requirements.

When the LS-series was introduced there was just one Corvette version rated at 345 HP. As the years passed the base engine was upgraded several times to the current 430 HP and the LS6, LS7 ,and LS9 were added. I expect the same evolution to apply to the new LT-series.

Since LT1 bore spacing remains at the traditional the 4.4", larger displacements, like 7.0L, will likely be possible, but whether or not larger displacement or boosted versions will ever develop is a function of future fuel economy regulations and Corvette sales volume.

But consider that this new base engine has nearly five percent more peak power than the current LS3. GM is also saying that it makes as much low end torque as the LS7, and the C7 is expected to be a little lighter. Further, they said to expect a C7 0-60 time of less than 4.0 seconds. Road tests say 3.9 for the Z06, and the current base engine is about 4.3 What more do you want?

If you want bragging rights that your Corvette has a top speed of over 200 MPH, well, you better start looking for a ZL-1 as the new C7 will probably only make something between the current base engine's 190 and the Z06' 197, but that's a way from the ZL1's 205 MPH.

Corvette's and other sports cars in the same performance category are so fast, it's ridiculous. I have a buddy who is obsessed with 0-60. He owns a Ferrari and a Porsche, so I asked him: When was the last time you did 0-60 in one of your cars, and I mean a high rev clutch drop - essentially a drag racing start - like what the magazine road test do. All I got in return was a blank stare. He'd never attempted this with any of his cars - at least in the last 30 years.

Beyond this, 2WD cars at the Corvette's performance level are traction limited up to about 30 MPH, so 0-60 is more a measure of tractive effort than acceleration, and AWD has a huge advantage.

A much more practical and real-world useable measure of performance is 30 to 80. This eliminates the traction issue and abusive launches that are required to get good 0-60 times, which most guys would never attempt with their own cars, anyway; but 30-80 represents something that can be done on almost any freeway onramp or coming out of a tight turn on a twisty road. You can extract this data from the acceleration times of magazine road tests which usually list 0-xx times from 30 to over 100 MPH.

Duke

[Joe L.]

Re: New gen v small block lt1

Since the new LT1 is a complete redesign despite not looking that much different on the outside from the LS, all new tooling will be required, and it's not practical to keep manufacturing the old design alongside the new design. For one thing they don't have the space, and this new more fuel-efficient engine is required to meet near term truck CAFE requirements.

When the LS-series was introduced there was just one Corvette version rated at 345 HP. As the years passed the base engine was upgraded several times to the current 430 HP and the LS6, LS7 ,and LS9 were added. I expect the same evolution to apply to the new LT-series.

Since LT1 bore spacing remains at the traditional the 4.4", larger displacements, like 7.0L, will likely be possible, but whether or not larger displacement or boosted versions will ever develop is a function of future fuel economy regulations and Corvette sales volume.

But consider that this new base engine has nearly five percent more peak power than the current LS3. GM is also saying that it makes as much low end torque as the LS7, and the C7 is expected to be a little lighter. Further, they said to expect a C7 0-60 time of less than 4.0 seconds. Road tests say 3.9 for the Z06, and the current base engine is about 4.3 What more do you want?

If you want bragging rights that your Corvette has a top speed of over 200 MPH, well, you better start looking for a ZL-1 as the new C7 will probably only make something between the current base engine's 190 and the Z06' 197, but that's a way from the ZL1's 205 MPH.

Corvette's and other sports cars in the same performance category are so fast, it's ridiculous. I have a buddy who is obsessed with 0-60. He owns a Ferrari and a Porsche, so I asked him: When was the last time you did 0-60 in one of your cars, and I mean a high rev clutch drop - essentially a drag racing start - like what the magazine road test do. All I got in return was a blank stare. He'd never attempted this with any of his cars - at least in the last 30 years.

Beyond this, 2WD cars at the Corvette's performance level are traction limited up to about 30 MPH, so 0-60 is more a measure of tractive effort than acceleration, and AWD has a huge advantage.

A much more practical and real-world useable measure of performance is 30 to 80. This eliminates the traction issue and abusive launches that are required to get good 0-60 times, which most guys would never attempt on their own cars, anyway; but 30-80 represents something that can be done on almost any freeway onramp. You can extract this data from the acceleration times of magazine road tests which usually list 0-xx times from 30 to over 100 MPH.

Duke

Duke-----

I would have expected a completely new engine based on a smaller architecture if GM thought there was a long-term future for gasoline V-8 engines. I think this design is "interim". Also, the fact that it's being manufactured at Tonawanda implies, at least for the moment, that it's either a "niche" engine or that manufacturing will eventually be transferred out of there or shared with other engine plants. GM has four engine plants now manufacturing the LS series engines and I would have expected one of those to be the initial manufacturing source for the new engine. In any event, I expect that they will continue to manufacture the LS engines for some period of time for trucks.

I agree that horsepower levels have gotten ridiculous. As I've said before, about the most that can be used on the street in any manner that even slightly resembles legality and sanity is 300 HP.