Must have been too complicated for the American market...... stir.
Apparently, but probably not quite in the way you think, Andy
Here's an excerpt I found on another website from a book by retired Corvette Chief Engineer, Dave McLellan called "Corvette From the Inside"
"Why the Gen III Doomed the LT5
The contrast between the Gen III [LS1/LS6 engine] and the LT5 engine is striking. The LT5 is both taller and wider, as a result of its double overhead-cam cylinder heads and its complex intake manifold. It became apparent that the next generation Corvette, if it were designed solely around the Gen III small block, could be significantly smaller and lighter than if it had to accommodate the LT5 engine.
Studies based on a large population of modern cars have given us the standard relationship between engine weight and total vehicle weight. Increasing an engine's weight by one pound means that the total car's weight will likely increase by two pounds. We estimated that taking 80 lbs out of the Corvette's engine would allow us to remove another 80 lbs from the chassis. In the case of the Gen III, reducing the engine's length would also contribute significant savings. Weight reduction of this magnitude is only possible when you're designing a car from scratch.
The planned future LT5 engine, with its even more complex valve train, would have been 205 lbs heavier than the aluminum Gen III. Thus a Corvette designed around the Gen III aluminum engine would weigh around 405 pounds less than the same car designed to use the LT5. As a result, the LT5 engine would have had to generate 55 hp more than the Gen III, simply to compensate for the heavier car. With the Gen III generating 405 net hp and the future LT5 estimated at 475 net hp, the effective power gain would have been a mere 15 horsepower. And, given an estimated $25,000 price premium for the LT5 engine, the cost of this small increment of power is astronomical.
The Corvette had reached a crossroads. We could design the C5 around the LT5 engine or we could design a smaller, lighter car that was fitted like a glove around the Gen III small block. By opting for the smaller package, we could achieve ZR-1 performance at the price of a standard Corvette. This was too important an opportunity to ignore. As we explored it further, we convinced ourselves and Chevrolet that this was the right strategy for the next generation Corvette. This, however left us with the conundrum that the far-superior Gen III might seem, to the consumer, to be low tech.
The Gen III uses computer management to control fuel and timing, providing smoothness, high power, and efficiency -- a very high-tech feature, but earlier forms of control -- such as the four-valve combustion chamber -- were what the public perceived as modern technology. We knew that the Gen III LS1 would do just fine without these older features, as they came at such a high price, in terms of size, weight, and complexity. Like the consumer, we had been accepting the notion that complexity was good. Yet, here was one case where just the opposite was occurring. The simple solution was almost as powerful, and it was smaller, lighter, cheaper, and more fuel-efficient. Whether it was considered high-tech or not, the Gen III was the better engine. So, in the end, the only logical choice was to back the Gen III small block as the Corvette's engine of the future -- even if its roots dated back almost 50 years."
Sounds "almost" convincing
but the only part I buy is that the GenIII was smaller and lighter. The rest of it, IMO, is simply an exercise in putting lipstick on the pig, and justifying a decision with benefit of hindsight.
"The General" went through a period in the 90's where their corporate arrogance was simply astounding; their attitude was that if they didn't invent it, then it simply wasn't any good. This was the beginning of the end for GM. This engine was designed by Lotus, not Chevy's engineers (strike 1), it was built by Mercury, not GM (strike 2), and the cost was probably over double what the GenIII (LSx) would cost to build in house (strike 3). Add to that the hand wringing bean counters who were probably moaning about what a complicated engine it was for the dealers to work on, and the potential for "in warranty" repairs, etc. and it's not surprising that Chevy bailed in favor of the GenIII, a "new" engine, but still based on the technology that has served them well for the last 50 years.
