the Buick/Olds V8 would have been handy in US production in the 70s, given that Leyland managed to stretch it from 3.5 to 4.9 litres. As I mentioned previously I think that the thermal properties of aluminium are such that compression ratios don't need to be dropped quite so much to manage detonation with unleaded fuel. So while the iron engines drop to 8.0 the aluminium only goes down to 8.5, giving it a performance and fuel economy edge, added to its light weight could make it the closest thing to a performance engine in the US.
AHC/WI: Successful Chevrolet Corvair
- Thread starter Delta Force
- Start date
So, maybe if GM had taken an existing, efficient engine, and put it the conventional position, but in a body that had some idea of light weight and good use of space.
I would have liked to have seen the Pontiac Tempest with a Buick 215 in place of the slant 4 (1/2 of a 389) and keep with rear transxle, but drop the goofy speedometer/rope drive and use a real driveshaft, in place becoming the GTO in 1964
Would have been a fast, light, cheap sportscar to fight the Mustang
The engine the rotary is being compared to in that article is the Oldsmobile 307, which was probably pretty much equal to the Chevrolet 305. The problem with a single rotor design is gonna be vibration. Rotaries are smoother running than reciprocating engines by design, but a single rotor design is going to have nothing to alleviate its vibrations, whereas a double would be rotating at different points and thus to a considerable extent cancel out the vibration. The better solution to this would be a smaller twin-rotor, but the fuel efficiency issue is going to remain here.
The GM rotary went out the window due to fuel economy issues. Wankel rotary engines struggle to have sufficient fuel economy to work well, particularly since their lack of torque forces them to regularly run at higher RPMs. This is no issue for a sports car (indeed, the torque curve being more potent at higher RPMs could be a help in a high-strung sports car, and the lighter weight and smaller size of such engines could be a huge plus), but in most other applications, especially considering the fuel crisis that struck just as the rotary began to be developed, it had no place. Rotaries could work well if you can get better fuel efficiency out of them, which is why IMO is GM was gonna use the rotary in a Vega or any car they would have been advised to go the Mazda route and use a smaller twin-rotor with forced induction. The higher RPMs of a rotary means that GM could have easily used a crank-driven supercharger instead of a turbocharger, because turbos at the time had all kinds of drivability problems which GM has by then long licked with superchargers. More to the point, with the Vega, its engine design could have been easily improved (and Soichiro Honda himself famously did just that with an Impala with a small-block in it), and the reliability problems the Vega had should have made a point to GM about such improvements, but GM at the time was as stubborn as a large, publicly-traded company could be.
Could the Corvair have survived as a sports car? Sure, but its still hard to justify. The first-generation Camaro was for its time a fairly-good handling car (particularly in Z/28 trim with its better springs, stabilizer bars and shocks, and putting radial tires and independent rear suspension would have probably improved that much further) and it was a massive sales success, not to mention a modern legend as musclecars go. The Corvair might have had a niche as a quick corner-carver, but it would have to be very inexpensive to do that, which would be hard to do with unibody construction. Now, it does have to be said that the Corvette's best sales numbers ever were in the mid-to-late 1970s (despite the fact that those Corvettes were the slowest, most anemic ones ever made aside from maybe the 1953-55 originals), so a small sports car from GM at the time would probably have had a sales future (especially since the British sports cars of the time were by then either outdated, were terribly built or both), getting GM to go in that direction would be devilishly hard. Making the Corvair a sports car in the "age of reality" as GM ads of the time spoke of is an interesting idea, but getting past GM's bureaucracy would be a challenge, no matter how successful its first generations are. The fact that the second-generation Corvair is one of the absolute best shapes produced in Detroit in that era (sharing the honor with the 1963 Chevrolet Corvette, 1969 Chevrolet Camaro and 1970-71 Dodge Challenger) works in its favor, but you need to get it to where it does not threaten the Camaro or Corvette early on.
Agreed on that one. The Buick/Rover V8 was a brilliant design for the time, and what IMO might have been an idea is that Leyland would get the ability to use the Rover V8 if they helped GM improve it. Leyland takes that deal, and the Buick/Rover V8 becomes the first example of GM co-operating with the British industry. (Considering at the time GM was selling transmissions to Rolls-Royce and working with Opel and Vauxhall for small cars for Buick to sell in America, this is not as far-fetched as it first seems.) British Leyland's formation would almost certainly scuttle the move, but as both companies would have the engines in use, both would probably continue to use it.
What also would probably help is GM using aluminum-block SB Chevy engines. They were well in existence by then, and GM had the equipment and technical ability to cast aluminum engine blocks. The main reason they did was cost - the same reason most Detroit cars came with carburetors and bias-ply tires until the mid-1980s. If GM's massive engineering corps had put as much effort into improving the basic mechanicals of the cars as they did trinkets and gadgets, they would have an edge on fucking near anyone in the world in car engineering by the 1980s. The Rover V8
Indeed. Why didn't Triumph use that instead of the of developing the notoriously unreliable Stag V8? It could have fitted in the GT6, the TR6, the Dolomite...
Triumph came from the Leyland side of the British Leyland merger, and the only reason that merger happened was because Leyland (which included Rover, Triumph, Land Rover and Standard) was prospering and British Motor Holdings (Austin, Morris, MG, Jaguar, Mini) was nearly bankrupt. The idea was that Leyland's expertise would return BMC to prominence. The result was simply beyond hope right from the start, with every problem imaginable. The Triumph V8 simply was a good base design with too many compromises - poor water pumps, roller link chains for engine timing, different engine block and head materials and poor head stud designs which was just asking for head gasket failures, atrocious quality control on cast components - and the Rover would have probably worked better, by the time the Stag was coming onto the market, the Rover V8 wasn't being produced in big enough quantities to supply Triumph and Rover. (Jaguar had the same issue, which is why Jaguar's fabulous inline-six remained in production until the 1990s.) And to be fair, the Dolomite's power unit wasn't bad for the time and better quality control and a little engineering bravery could have made it great - the 16-valve Dolomite Sprint engine could make 155 hp on pump gas, a spectacular output for a carbureted two-liter inline-four in the early 1970s - but BL, which is probably the single greatest management disaster in the history of transportation (though the Penn Central Railroad in the United States would be a real rival in this regard), simply couldn't do much right because of both its own very poor management and its truly insane levels of labor problems.
The trouble is, rear-engined cars look efficient because you need a lightweight engine for them to handle at all well. That means, for a longitudinal engine (the simplest way, and GM need simplicity) aluminium, air-cooled, flat (lower CG and better air flow than V) and no more that six cylinders max to keep it short. It's not hard to beat the VW - the Corvair is basically a scaled-up Karmann Ghia - but hard to do fast and powerful. Porsche had been refining that for twenty years, and arguably wouldn't get it right (for drivers of average ability) for another twenty. This was GM's first try.
Fair points, but Porsche's efforts show that it can be done. I've always felt that the Corvair would have been best if they moved the engine forward and done a similar transmission setup to the Lamborghini Countach, with the gearbox between the seats and the drive back to rear through the sump. Porsche's engineering efforts, it should be pointed out, didn't focus on the 911 for much of that time - by the late 1970s, they had planned to use the 928 to replace the 911, but it never happened because Porsche's customers preferred the 911, handling quirks and all. GM's engineering corps could have made the Corvair a true rocketship, but that had costs, and that was the problem - the Corvair couldn't, and didn't, pay back those costs.
The problem with the Saab/Triumph idea wouldn't be engineering, it would be politics. Remember why BL's products had such poor quality across the board - their industrial unrest was so bad that its a wonder they could get anything done at all. Britain's unions in the 1970s really did rule the nation, not its government, and one of the results of that was that BL was unmanageable and found any form of quality control nearly impossible. The flaws and failures in the cars of the time beggars belief - the poor Triumph V8 design, cars with wood trim that hadn't been sanded which gave their owners splinters, trim pieces falling off, cars delivered with no window glass, atrocious paintwork, at least a few Triumph TR7s where the back axle fell out of the damn car - and the fact that the lines duplicated all over the place. Really, what would have worked there would have been for BMC to crash and for Leyland to pick up the pieces, but Britain's industrial unrest at the time would have been made worse by this. Really, any Triumph/Saab collaboration would have almost invariably fallen apart on the British side, even if the Swedes would probably have done an excellent job. (I'm having visions of that V8 also finding its way into other cars with the same chassis as the Saab 9000, namely the Alfa Romeo 164....)
Getting back to the Corvair, the sports car angle could work, but it would ultimately probably have to ditch the rear-engine layout. I can see it being a transverse mid-engine layout, as GM's cars went more and more in this direction in the 1970s and its no more difficult to install such a drivetrain than it is to put an engine in a front-engine/front-drive conventional sedan. (This is part of the reason the Fiero worked - it used what amounted to a J-body drivetrain and X-body suspension in it.) The Corvair in such a way would be an interesting complement to the Corvette, but amongst the horsepower wars of the Muscle Car era, the Corvair would have been hopelessly outclassed unless you managed to jam a V8 in it, which would pretty much require a bespoke chassis to be designed, a hard sell in the late 1960s. It would either be that or go front-engined, probably using a modified Vega chassis, but is that really a Corvair?
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True on this front, but using better cylinder head designs could have made this work better still. GM has sufficient pull with oil companies to push for better-quality fuel at the time, why nobody there did this is something I've never understood. (Being that GM had built tens of thousands of heavy trucks and thousands of diesel locomotives with mechanical superchargers by then, too, why that didn't get used is also a mystery to me.) Using aluminum blocks was expensive, sure, but if you could do it (and GM could), having the edge in power on your rivals is a huge selling point, is it not?
True, but it wouldn't have had the Mustang's styling, and the 1964 Tempest with the 389 in it WAS the first Pontiac GTO. The transaxle design would have been an additional cost for GM (most Detroit cars at the time attached the engine and transmission together before putting it in the car), which is one of the reasons it wasn't likely to happen.
Fuel injection in the late 1960s isn't necessarily ASB; it's already been done by Mercedes Benz in a reasonably high volume production engine (the M100) as well as a balls-to-the-wall tour de force (the M198). Sure, they took advantage of their experience with diesel engines, but it's not like GM is lacking in said experience; they could just transfer over a department or two from Detroit Diesel to work things out. That being said, mechanical fuel injection in a flat-6 engine poses unique challenges; two injection pumps will probably be necessary and synchronizing them is going to be a bitch.
Delta Force
Banned
There were some interesting mid-engine vehicles designed by General Motors in the 1960s and 1970s. The XP-882 was a mid-engine vehicle designed in 1969 with a V-8 engine the Reynolds Aluminum Car being built to a similar design. The XP-882 design eventually evolved into the XP-895 and XP-897GT designs, which respectively featured four and two rotor Wankel engines. The final design was the V-8 powered Aerovette, which was actually approved for production. In 1976 the Aerovette was approved for production starting in 1980, but the project was later canceled.
The reason why it is of interest for this thread is because the design is mid-engined and also greatly resembles the Monza and Monza GT Corvair concept cars.
The reason why it is of interest for this thread is because the design is mid-engined and also greatly resembles the Monza and Monza GT Corvair concept cars.
Delta Force
Banned
Since there would have to not be an energy crisis anyways for a Wankel anything to work, and an American sports car of the era wouldn't use a V-6, there would have to be some kind of market differentiation to prevent cannibalization of sales between the Corvair and Corvette. Any thoughts on what might have worked? What about a V-12 or V-16 like the one General Motors was developing for Cadillac in the 1960s?
I would say that the best bet engine-wise to get real differentiation would be a V6 with forced induction, either a short-stroke, fast-revving unit with a Roots-type supercharger or a turbocharged one, assuming GM's engineers can make a turbocharged performance car without the engine difficulties and/or turbo lag lots of high-performance turbo cars of the 1970s (BMW 2002 Turbo, Saab 900 Turbo, Audi Quattro, Toyota Celica Supra) suffered from. That's a tall order, but GM's engineering staff could do some pretty awesome things when they needed to.
A V12 Corvette would be one possibility, but that costs a sizable chunk of money, and even if GM cheaped out and made a V12 from two existing V6s or inline-6s its likely to have reliability problems, and since GM didn't start going to aluminum blocks until the late 1980s, I shudder to think of what kind of handling a V12 Stingray would have with all that weight up front. I'm not quite sure that this would even be a good idea if GM did have the moxie to pull it off - why would one build a big V12 for one car?
Delta Force
Banned
What about using a new boxer engine? The Corvair originally used a boxer six with aluminum cylinders.
The V-12 would come from Cadillac, which was considering producing a clean sheet engine in the 1960s and 1970s. There were also some proposals for a V-16, although they usually involved bolting two V-8 engines together. A V-12 Corvette would only work with the engine in large scale production at General Motors, such as at Cadillac.
That could work, but Boxers are often more difficult to work on and their physical size also becomes an issue, as you can't mount an engine above suspension components (which you can do with a V-design engine, and nearly all big-block American cars of the era did) without putting the center of gravity very high up. (Ferrari did this with the Berlinetta Boxer and didn't like the result, which is part of the reason the succeeding Testarossa was over six feet wide in the rear.) This means either the Corvair needs to have entirely in front of or entirely behind the rear wheels, the former causing potential packaging issues and the latter quite likely making for an evil handling car without proper suspension tuning.
The problem with this is that the big Cadillac V8s got all the way up to 500 cubic inches, which is 8.2 liters. What you could do here is have Cadillac go with the V12 instead of its 472ci and 500ci V8s, but these engines are still much too big for the Corvette unless you can make them have sufficient design flexibility that a long-stroke torque beast for the Cadillacs of the time can be used in the same block as the Corvette. I can only see that working if you use Corvette engines with very short strokes.
For example, assume this V12 uses a 3.625-inch cylinder bore. Using a 3.75-inch stroke on this engine gives you a displacement of 464 cubic inches, about the same as the Big Cadillac engines where they started. A 4.0-inch stroke on the same block gives you 495 cubic inches, while using a huge stroke like 4.25 inches (the Cadillac 500 V8 is a 4.3-inch stroke) gives you 526 cubic inches. Any one of these would give you enough torque to rotate the Earth, but such a massively undersquare engine invariably would have a relatively low RPM limit, and you run into potential issues with connecting rod and crankshaft clearance. Now, if you take this same block and put a short 3.0-inch stroke crankshaft in it, you get a 372 cubic inch motor which, being considerably oversquare as it is, you would get an engine that would rev far quicker than any Detroit V8 could ever dream of, doubly so if you use overhead camshafts or solid lifter camshafts, though the former will add weight and complexity and the latter will have much increased engine wear. Whether its worth the gamble is an open question, but there is no way making this thing with a cast-iron engine block makes any sense, particularly the Corvette version (as the iron block increases heat losses, not to mention the huge weight and size of the engine). An aluminum block would be a must, and with the Corvette version cooling would also be important, though the higher RPMs of such an engine would probably allow for shorter gears in the transmission and/or the differential, which could be beneficial for acceleration and throttle response though probably not for fuel efficiency.
Delta Force
Banned
One of the advantages of a boxer engine is supposed to be a lower center of gravity. Is that only the case for rear mounted engines, such as Porsches? Why can't they be mounted over the suspension?
As for the V-12, Cadillac was targeting around 500 cubic inches displacement. That would be rather large and a car with it probably wouldn't be able to out manuver a Ferrari or Jaguar, but it would likely be able to beat them and American muscle cars in straight line acceleration.
As for the V-12, Cadillac was targeting around 500 cubic inches displacement. That would be rather large and a car with it probably wouldn't be able to out manuver a Ferrari or Jaguar, but it would likely be able to beat them and American muscle cars in straight line acceleration.