I have always wondered what would be the pros and cons of a small displacement V8. Maybe something like 4.0L? Couldn't a 4.0L small block be just as powerful/efficiant as a 3.6L V6, but cheaper and more packageable?

 

Having followed this sort of thing for a while, the answer appears to be no.

The problem is that the V8 has more friction for a given displacement.

 

I am not sure...I mean..wouldn't some drivetrain drag be saved with 1 cam vs. 4? Additionally, don't a lot of race cars run really small V12's? Not to mention a V8 is better balanced than a V6.

 

More cylinders with the same displacement generally gives more power, because you can rev higher. Of course, that assumes the rest of the engine lets you rev that high.

If it was a great idea, you'd see a bunch of small V8s out there.

 

I remember reading a long time ago that Dodge used that thinking with the Viper. Ten smaller cylinders vs. eight bigger ones in the Corvette. I don't think the theory ever really panned out well enough. I don't remember the viper ever showing significant power or fuel economy. Havn't looked it up though.

 

Formula 1 once ran V12s and even V10s. Currently they're running V8s however I believe they're discussing going back to V6s for next season to save costs.

Less cylinders, means less moving parts and in general means less wear. If you simply downsize the V8 to 4L or whatever, you're going also drop in power. To make up for that you can run higher rpms, but that means more wear, higher quality parts, tighter construction tolerances which means more $. By switching to a turbocharged V6 you're making similar power, plus you also get the advantage of taking wasted energy and plumbing it back into the engine. The result is a greener engine with more power, more efficiency (work efficiency not necessarily fuel efficiency), less materials, and eventually less $. Smaller engines with power adders are our future I'm afraid, at least until we run out of oil.

 

I don't think having a 4.0L V8 would be a good idea for the next gen Camaro - it's basically not going to have much more power or get better fuel economy than you can get from a the current 3.6L LLT V6.

This is why - I suggest that if GM decides to put a small block V8 in the 6th Gen Camaro - it should be in at least 4.8L. Because - it would basically be the current 3.6L LLT V6, with two extra cylinders. Also there would be a noticiable increase in power over the 3.6L.

 

But the 3.6 is a 60 degree V6 and that would make for a very unbalanced V8 and odd. A better idea would be to make a V8 share parts with one of the I4 engines (imagine a turbocharged 4.0L LNF based V8 making ~500 hp ). But then it wouldn't be a small block and lose all packaging savings that comes with the layout.

 

Okay if GM bases the new V8s off the Ecotec I4s. Then they should go with the 2.4L - which would be 4.8L , with DI - it could easily make about 400-420hp. And that engine could be stroked to be about 5.4-5.7L range.

 

The current V8s are already in that range...

 

Why would they need to be so large? What is obsession with size?

 

Why not? If Alpha is going to come in at the golden weight number, then a 5.7 could be a "top dog" engine. Remember 12 years ago the "old" Gen III 5.7 was knocking down 30 mpg's(with easier breathing) with a weight similar to what Alpha is supposed to be. Some 4th gens were in the 3700-3800 range, so Alpha should be lighter.

 

Because bigger displacement generally means more weight. If the weight is down then you don't need huge power numbers to get equal performance. Lets move beyond needing the bigger numbers and look at the performance possibilities a smaller, lighter platform can develop.

 

According to GM's press reports over that last 3 years.

Here's what we can gather about the Next Gen V8s which is dubbed "Ultra".
It is said to be of a DOHC design and will be much more fuel efficent than the LS series is. these "ultra" V8's will be the powerplants for the C7 Corvette, next gen Cadillac V-series, and 6th gen Camaro, as well as the large trucks.

The size is suggested to be between 302-350 ci. The new V8 are now slated to make there first appearence in the 2013 Corvette.

 

Ultra is dead guys.

The V8 you'll see will be a very familiar looking successor to the current Gen IV smallblock. And GM will make hundreds of thousands of these Gen V smallblocks every year. You'll see them in trucks, Corvette, Camaro, ATS-V and CTS-V.