Chevy abandons the L/S Motor!

What it really means is that all the aftermarket goodies for the mark IV engine will have to be retooled to fit the mark V engine....

Russ
 
wrascal said:
What it really means is that all the aftermarket goodies for the mark IV engine will have to be retooled to fit the mark V engine....

Russ
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I suppose so, but with 17 years of production of the LS engines, there will be a never ending market for the stuff now being made.

Very little of the original engine remains with the new Gen V motor, but the original bore spacing still remains unaltered after all these years.

I like the direct cylinder injection, which has allowed yet another boost in compression. Note the over 2,000 psi fuel pressure to the cylinders! You still need a high pressure fuel pump to get the gas from the tank to the engine. Chevy has put the super high pressure pump right inside the valley to help with the noise - or so they say.

No crate motors available until later toward the end of the year.
 
Maybe its just me, but I never really considered the LS engines, or the new Mark V to be a "small block", in the way I look at these engines. Other than a few basic dimensions, anything from 1997 onward (the LS engines), is so different from the earlier small block engines, that I just don't look at the newer engines as being small blocks. As for the Mark V, the way I see it, its just an evolution of the LS engine.
 
clean8485 said:
Maybe its just me, but I never really considered the LS engines, or the new Mark V to be a "small block", in the way I look at these engines. Other than a few basic dimensions, anything from 1997 onward (the LS engines), is so different from the earlier small block engines, that I just don't look at the newer engines as being small blocks. As for the Mark V, the way I see it, its just an evolution of the LS engine.
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You have a good point there. But since Chevy chooses to call this their Gen V small block, it's good enough for me. I suppose this would be as compared to a big block.

As for the evolution part, you're right. But then every small block since 1955 has seen some sort of evolution.

Kind of like the latest 2015 Vette, introduced this morning in Detroit. Wildly different than the original 1953 6 cylinder car, but still a Corvette.
 
A bit more info...

What exactly makes a small-block a small-block? The design features that haven’t changed since the 1955 Chevy debuted this engine include eight cylinders arranged in a 90-degree V formation, a single-cam pushrod-and-rocker-arm valvetrain, and bore-to-bore spacing of 4.4 inches. Through the first four generations, GM engineers fiddled with induction, exhaust, ignition, valvetrain, and structural details galore to elevate the original 162 hp to the latest Corvette ZR1’s illustrious 638-hp high-water mark—a huge increase in power even before considering the gross versus net horsepower measurement difference.

Compare and Contrast

Key features that carry over from Gen IV to the new LT1 Gen V Corvette V-8 are the bore, stroke, 6.2-liter displacement, camshaft location, and deck height. As before, the deep-skirt aluminum block has cast-in iron bore surfaces, a forged-steel crankshaft, cast aluminum pistons, and forged powder-metal connecting rods. A common aluminum cylinder head is used on both sides of the engine by simply reversing its orientation. A dry-sump lubrication system—available only on today’s Corvette Z06 and ZR1 models—will be optional on the base C7.
 
It is a shame Drifter doesn't still look in here, he was telling me once about the development of some other series Chev Engines they had been working on, now that man could have opened your eyes about which engine does what etc as well as future Chevy engines.
 
I know that different people look at these engines from different perspectives. What I'm trying to say is that when the LS series engines were introduced in 1997, other than the basic layout of the engine, and a few basic dimensions, they share almost nothing with the previous small blocks, that were in production from 1955 to the late '90s. The earlier engines shared great parts interchangeability, which isn't the case between the earlier small block, and the LS engines. There are virtually no interchangeable parts between those engines. The LS series engines have features that the earlier small blocks simply don't have (deep skirt block, 6 bolt mains, coil-on-plug ignition, separte engine valley cover, etc.). Even if you look at a GM Performance Parts catalog, small block engines and components are listed in a completely separate section from LS and LSX engines and components. That's why I said earlier that for me, I tend to look at the later LS and LSX engines as something separate from the earlier small block. Just my opinion.
 
I'm surprised that chevy didn't move toward a 32 valve twin overhead cam design like the ford cobra engine..

Russ
 
wrascal said:
I'm surprised that chevy didn't move toward a 32 valve twin overhead cam design like the ford cobra engine..

Russ
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Russ, I've read a discussion about that from GM. A large part of the reason was that the LS series of engines and now the latest LT series are delivering plenty of power without needing to go to the considerable additional expense and complexity of the Ford modular engine (I presume that's what you're referring to). I haven't checked into the cost or weight of the 32 valve motor, but it will be interesting to see what those numbers are.
In this month's PHR mag they have a shootout between 27 of the best engine builders using the engine of their choice.
The criteria seemed somewhat odd to me, but the Ford 32 valve motors put out 736/644, 720/666 and 775/632 (hp then torque) and were the winners. The LS motors put out 771/677, 748/621, 741/676, 741/656, 675/615.
The 572 cu. in Ford made 870/815 and a big block Chevy made 852/759 and yet they ranked last. I still can't quite figure out how the lower power motors were ranked so highly.
I will say that the 32 valve motor really has a dead flat torque curve. It's already at 500+ at just 3,000 rpm. Mind you, the builders could do whatever they liked to the motors short of power adders like turbo/supercharging or nitrous.
 
wrascal said:
I'm surprised that chevy didn't move toward a 32 valve twin overhead cam design like the ford cobra engine..

Russ
Click to expand...

Maybe they may in the future, like the Caddi was the North Star engine or something like that, I can't recall what it was called now, it was a front wheel drive engine though.
 
As cocobolo has pointed out, the LS engines (and their derivatives) are able to produce really good power without the need for the complexity of a 32 valve OHC design. GM did experiment with a 32 valve engine-the LT5 that was available in the Corvette ZR1 in the early '90s, but it was a complex engine that was expensive to build (they were actually produced for GM by Mercury Marine). Once the LS engines were introduced, it became clear that the LS could produce as much power (and in some cases much more power) than the LT5, so GM stopped producing the LT5.
John, as for the Cadillac Northstar, (and its little brother 4.0LT V8 that GM used in the Olds Aurora and one or two other models), I remember when GM first brought that engine out. I worked at a Cadillac dealer at that time, and I remember GM saying that it was supposed to be "the engine of the future". It was a pretty good engine for its time, but it was fairly complex, and we did have some problems with it, and I think that the Northstar had just run its lifespan for GM. Now, it looks like GM is trying to use the 3.6LT V6 (in some cases with 1 or 2 turbos), as a replacement for the Northstar in some of its vehicles. They're probably trying to develop an engine that will produce similiar power to the Northstar, but with V6 fuel economy, since that seems to be a big issue these days. By the way, GM did use the Northstar V8 in a rear wheel drive vehicle. It was used in the Cadillac XLR, which was produced from about 2004-2006. There was even a supercharged version called the XLR-V. The car was built on the Corvette platform, and didn't sell very well, I think mainly because, compared to the Corvette, it was underpowered, so it was only available for 3 or 4 years, then it was dropped. There are several aftermarket companies in the States that make conversion parts to allow the transverse Northstar engine to be used in a rear wheel drive application. I saw one in a '34 Ford woodie wagon at a car show years ago-it was pretty slick. With a bit of modification, you could use the automatic transmission from an S10 truck that had a 60 degree V6 engine, since the bellhousing bolt patterns are very close. Just a bit of trivia there.
Thanks for putting up with the long-winded post.
 
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