“The Jaguar’s reliability record, as everyone must know by now, is not enviable.”
Sorry, I just have to admire a lovely bit of writing there. Not good news for Jag at that time, obviously, but the word choices themselves are fantastic-elegant and understated, just like the subject car.
I also have to marvel at the R&T crew’s ability to craft a reason to basically drive the same high-end cars they drove only a year or two before. And why not?
Of the lot, I’d love to hear the noise the Jag V12 made! Hard for me to imagine why someone would want the top that takes two people to remove, though. I mean, you want to go out for a sporting drive on a nice day, but your spouse is off doing something else and you’re the only one home. Kinda ruins it if you can’t take the top off, it seems. Maybe it’s just the way it was, but I can’t imagine being smitten enough by the convertible concept to go through the hassle.
Which is why you had a hoist and pulley setup in your garage centered over your car. One person operation to remove, reinstallation can be done by one, although two is easier. I remember ads for these kind of setups back then.
I used to put the hard top on/off my MGB by myself. Undo all the latches, sit in the passenger seat, place hands in the center of the roof and push up. Then the tricky part – stepping out the door with the roof balancing above you, stepping a few steps away from the car, then squatting down under the roof until it gently touched the ground. Then crawl out from underneath. Putting it on was pretty much the reverse, except instead of holding it above my head I would balance it across my shoulders, stand up and shuffle over to the open door, step in and lower it best I could into place. Then some minor shuffling around to get everything squared away, latch the latches, and good to go!
As already mentioned, the 1975 Vette with an L82 had 205 hp. The base L48 only had 165 hp,making 1975 a low point for horsepower in a Vette. 1975 was a low point for horsepower from GM and Ford in general, much of it due to the restrictive catalytic converters that were introduced that year.
FWIW, C/D tested a 1975 Vette with an L82. It ran 0-60 in 7.7 seconds and through the 1/4 mile 16.1 sec @ 87.4 mph. Top speed was observed at 129 mph
All of the cars on test were ’74 models (or ’73, in the case of the Dino) — I looked it up, and this article originally ran in the February 1974 issue of Road & Track
I must have scanned this from a Buyers Guide that was dated 1975, or? The compact station wagon comparison had the same issue. I’ve corrected the dates now.
Given the lack of any commentary, I must have thrown these together in haste at the time.
Ate Up With Motor
Posted February 9, 2024 at 11:17 PM
I assumed the actual scans came from a later compilation published in 1975, probably collecting articles from the previous calendar year.
An interesting question – I can supply the answer in the case of the MB. I bought a 1977 450SL early in 2017, and it is very, very similar to the 1975 tested here.Most of what the reviewers said rings true today, though of course the car seems primitive in a world 43 years on.
In June of 2017 I bought a 2017 Mercedes SL550 roadster, a lineal descendant of the 450SL and it occupies the same market niche, though the argument could be made that it is more sporty.
I am not sure what the cost of this would have been in the US, but in Canada where I live, it was roughly $135,000 with an MSRP of $153k- against an inflation adjusted $17,000 1975 dollars figure of $77,500 in the US. I would guess the car in the US would have been $115-$125K so quite a bit above the inflation adjusted cost of the ’75. Now, compare the content, capability and performance of the two cars and you see where some of that price difference lies.
My late father remarried in 1979, a year after being widowed, and within 6 months had purchased for the new wife a new 1980 450SL, which was (with leather and alloys, like the car tested here) $37K. Such a vast increase – more than doubling in 5-6 years – was presumably attributable to more than just inflation and exchange rate fluctuation.
Fascinating- love those reprints. I couldn’t help but notice, though, that the Corvette was the fastest in the 0-60 and 1/4 mile, 2nd in the slalom, cost 2/3rds the price of the closest competitor, and still got panned for being crude and unsophisticated. Some things haven’t changed in the past 40 years (grins).
I do have to add that the loss of the chrome bumpers took away a lot of the charm those sharks had.
The ’74 Vette tested here was crude, with a chassis dating back to 1963, but I agree it did perform well under test conditions on smooth roads. That said, I’d argue a modern Vette is not crude anymore. Ever since the revolutionary C5 Vette, it has been getting progressively better and no longer crude like Vette’s of the past. The current Vette is world class and just an amazing performance machine period. It does everything well and without any major compromise.
I loved Corvettes even though I never really considered buying one. While shopping for a car one time I looked at a C3 at the used car lot and noticed it had a 4sp. Rounded up a salesman and took it for a drive. Seriously, don’t meet your heroes.
Nice to read a comparo that has nuance and real-world driving considerations. Today’s R&T and C/D are about little more than lap times and complaining that other cars are not Porsches (or in C/D’s case, Nurburgring Camaros).
And how about the value change over time! Of course the Ferrari wins, followed by the Porsche, but the Merc looks like the biggest-dollar loser. I suspect that a groovy guy like our test pilot still has the Vette.
“Today’s R&T and C/D are about little more than lap times and complaining that other cars are not Porsches (or in C/D’s case, Nurburgring Camaros)”
You have a good point here. I would go even further to add that car magazines (at least those that I have access to) are way disconnected to most people’s tastes and expectations about cars. How many testers have complained that cheap small economy cars have “hard plastic panels” and other smart conclusions like that?. What one can expect from a vehicle like that? Connolly leather? And why should I care about road tests on every new special ultra limited edition of every sports car in the market ? Maybe they are targeting 14 years old kids and totally gave up adult readers.
Five exotic open sports cars. Mmm, I’d classify the 450SL as a personal sports coupe but not a “sports” car. I have personal experience with two of these cars and indirect with one. My father owned a 72 911E Targa and a 74 450 SL which are close enough for comparison. These two could be the 1960 Corvette vs. the 1960 Thunderbird in that maybe on the same spectrum but opposite poles.
The Porsche was my idea of a sports car. Taut, quick, and somewhat noisy. Aren’t open sports cars supposed to be noisy by description? So I am OK with that just as I would in an MGB or Fiat 124. The car has that unique sound that only a 911 can have both inside and out. One could hear this car almost 100 yards away as my father came up the long road to our house. Also had that unique rear engine 911 smell.
The 450 SL was a very quiet car on the road. It is more luxury than sports and appeals to a completely different clientele. Being front engine it was more familiar to me on the road. The Porsche was news to me on some certain curves around where I lived. Luckily I stayed on the road, that first time, otherwise I wouldn’t be writing this today. What I recall most was the seating between the two. No bolster on the 450SL and the seat was fairly flat so on hard braking one would slide forward towards the wheel. However, plenty of leg room which the 911 didn’t have considering my 6’1″ height. The shifter would always hit my right knee as my right knee was right into the console. So the 911 was good for a short hop along Skyline Blvd. down the San Mateo Peninsula while the 450SL was the long distance tourer.
As for the Corvette, a friend had a 72, which had more power for going flat out but the handling and suspension would be primitive against those other two foreign makes. Maybe the best America could offer at the time although if I had to choose American then it would have been a properly set up 1966 Shelby GT350.
Some quite-surprising findings in this, but the most notable thing to my eyes is that the 20 y.o. Chev small block, all iron, pushrodded, one carbie and less than 400cc bigger than the 2 y.o. twin cammed, all alloy, four-carb uber-swish Jag, puts out the same power, and on regular fuel too. Just why was it that the sophisticated designs were so incompatible with US emissions stuff? You’d surely think the cruder design would suffer a good deal more. I get that higher compression (because of lower capacity) might create more difficulties till electronic injection etc began to even things out (hence the low comp on all the Euro ones here), but the Chev is 9.0:1 – and the Jag reduced to just 7.8:1. Doesn’t make any obvious sense, but at minimum, it surely shows what an essentially fine thing the GM engine really was. I don’t like the ‘Vette of this era one bit, but it’s also intruiging to see that if it had had the normal suspension, it would’ve given all the Euros here a good haircut – or at least a good shave – on any circuit and in the real world. In a considerably cruder fashion, yes, but a haircut is a haircut.
Of course, if I was an actual buyer in ’74 for this quartet, I’d pay three times the Chev’s price just to see that gorgeous Fazza daily, and daily hear it sing – well, alright, on the days it wanted to, then.
Keep in mind that the Jag V12 was really not designed as a high performance engine. It had that less-than-stellar “Heron” cylinder head with dished pistons, probably rather small valves and rather restrictive and long intake ports. All of this was of course very different from the classic XK engine with its DOHC and hemi heads. This explains why the original non-smogged V12 only produced 272 hp, slightly more than the XK’s 265 hp.
The V12 was originally conceived as a DOHV hi-po engine, but late in the game it was drastically dumbed down to do service in large and heavy saloons, hence the completely redesigned SOHC non-hemi cylinder heads.
It’s a classic example of the confused thinking that was starting to permeate the British industry at the time, but then we can argue that the Jag’s future was more in line with MB’s and not serious sporting cars.
As to the Chevy V8, well its cylinder head was brilliant from day one despite its plebian intentions, and it was carefully developed from then on, along with its camshaft profiles, intakes and exhausts. Despite being de-smogged heavily, it could still breathe, for the time being. Unfortunately that would get worse over the next some years. In fact in 1975 the max power from the 5.7 L V8 was down to 205 hp, close to the low point (200hp in ’82) in its long and illustrious career.
The V-12 valves were 1.625 intake, 1.36 exhaust. The Heron heads were selected primarily for better emissions performance, although Jaguar also found that they produced better mid-range torque than a DOHC hemi design, which they also considered.
One question – I don’t know whether this is generally the case, but it seems like American manufacturers have often skimped on shock absorbers, leading to poorly damped suspension. Seems like this is the case here with the Corvette. Could the issues with the suspension be helped by just putting on some high quality shock absorbers? Realizing that the spring rates were still pretty stiff, and that would be harder to fix.
Also, my understanding is that a lot of the choices for engine size in Europe (Japan I don’t know about) were really driven by tax rates that were based on engine capacity – and in some cases such as England that formula solely considered the cylinder diameter and number of cylinders – leading to excessively long-stroke engines.
The small-block Chevy V-8 as I understand it made more power, was lighter, and could be just as economical as the Jaguar 6, but the Jaguar 6 was smaller in displacement, and so taxed at a much lower rate.
Yes, American manufacturers tended to skimp on shocks, and it used to be one of the top recommendations to improve handling by the magazines. Eventually that changed as handling quality became a more competitive factor.
The British tax base don bore size actually ended in 1947, replaced by a flat tax in 1948, so the reason many British engines were undersquare after the war was because the manufacturers had invested in the design and facilities to make them that way. But new designs after 1948 commonly weren’t undersquare; UK Ford’s new “Kent” ohv four was one of the most oversquare engines ever built.
Taxes on displacement in Europe varied by country, so that was not a consistent thing. The one consistent was high fuel prices, so smaller displacement engines were invariably more commone there for that reason alone. Also, European cars rarely had lots of power-robbing accessories like automatics, a/c, etc., so they did ok with their smaller engines.
Since the UK had a flat tax since 1948, your comparison of the XK engine and the Chevy V8 are not relevant. Which explains why American V8s found their way into several British cars, like the Bristol, Jensen and others, and were highly desirable as a consequence.
The XK engine was designed to be built in 2.4 L and 3.4L versions originally, so they only had so much room to grow displacement, 4.2 being the maximum for that design. That’s why they built the V12, as a larger engine for the increasingly heavier sedans.
The shocks on my Dad’s 1979 Chevrolet Impala were limp and weak from new. They lasted all of 30,000 km, when they were replaced by quality gas shocks. It transformed the way the car drove, making it much more buttoned down and controllable.
In those days it was common for new car buyers to change the shocks on their new car. Tires were another place Detroit skimped and were often replaced with the shocks.
Didn’t know that the UK went to a flat tax in 1946! I knew it happened at some point. The Jag engine is still a long-stroke design, is that partly because development began during the war?
Still, all the European makes, but especially Britain as I understand it, would be export-focused, so anything that made their cars less appealing (e.g. large taxable displacement) anywhere would be a consideration, I would think?
In any case, interesting to note that the Chevy V-8 here gets better fuel mileage than the Jag, and not that far from the Mercedes, though it has the benefit of (early) fuel injection.
Harley has usually skimped on good shocks too, probably for similar reasons – they figure most customers won’t care/notice, and those who do will go out and get what they want.
In terms of the development of the XK engine, it’s hard to say whether the outgoing tax had an influence or not. Oversquare engines were simply rather rare at the time. The VW engine was quite unusual in being oversquare when it was designed in 1936, and that turned out to be very advantageous in allowing it to run at max. power indefinitely with less wear and tear.
FWIW the 2.4 L version of the XK engine was oversquare, because it was created from the 3.4 by shortening the block and stroke.
I assume you know that very many modern engines are also undersquare? Like the classic Honda fours? And many others. Turns out that undersquare engines are easier to desmog, and their torque curves are advantagous, and their inherent breathing lomitations are readily overcome by 16 valve heads.
Ate Up With Motor
Posted February 9, 2024 at 11:14 PM
In terms of the development of the XK engine, it’s hard to say whether the outgoing tax had an influence or not.
Walter Hassan said it did, although it was not the sole consideration. He said:
“[T]he XK engine was designed at a time when a now-obsolete form of taxation was in vogue, where the tax was related to horsepower. The tax was calculated on the bore size and this, of course, had a paralyzing effect on engine design in Great Britain until 1947, when the law was changed. … The pre- and immediate postwar Jaguar push-rod 6-cyl engine of 3 1/2 liter capacity was, at the time, considered an excellent engine of its type. The crankshaft was undoubtedly a very satisfactory component and, therefore, provided a sound basis around which to design the XK engine. The cylinder proportions were then fixed at 83 mm bore X 106 mm stroke for 3.4 liters.”
(This is from his 1972 SAE paper on the V-12 engine, which provides a detailed and, given the source, presumably authoritative discussion of Jaguar’s thought process with regard to the development of the V-12.)
Thank you! No I guess I hadn’t kept track. But it makes sense that, if one is seeking thermodynamic efficiency and clean combustion, the ideal configuration might be different than the classic (for racing) oversquare design, which is optimized for creating the maximum amount of horsepower for a given displacement and/or weight.
“The Jaguar’s reliability record, as everyone must know by now, is not enviable.”
Sorry, I just have to admire a lovely bit of writing there. Not good news for Jag at that time, obviously, but the word choices themselves are fantastic-elegant and understated, just like the subject car.
I also have to marvel at the R&T crew’s ability to craft a reason to basically drive the same high-end cars they drove only a year or two before. And why not?
Of the lot, I’d love to hear the noise the Jag V12 made! Hard for me to imagine why someone would want the top that takes two people to remove, though. I mean, you want to go out for a sporting drive on a nice day, but your spouse is off doing something else and you’re the only one home. Kinda ruins it if you can’t take the top off, it seems. Maybe it’s just the way it was, but I can’t imagine being smitten enough by the convertible concept to go through the hassle.
Which is why you had a hoist and pulley setup in your garage centered over your car. One person operation to remove, reinstallation can be done by one, although two is easier. I remember ads for these kind of setups back then.
I used to put the hard top on/off my MGB by myself. Undo all the latches, sit in the passenger seat, place hands in the center of the roof and push up. Then the tricky part – stepping out the door with the roof balancing above you, stepping a few steps away from the car, then squatting down under the roof until it gently touched the ground. Then crawl out from underneath. Putting it on was pretty much the reverse, except instead of holding it above my head I would balance it across my shoulders, stand up and shuffle over to the open door, step in and lower it best I could into place. Then some minor shuffling around to get everything squared away, latch the latches, and good to go!
I didn’t think the Corvette made that much horsepower in 1975, I always thought it was 200bhp instead of the 250bhp that they’ve tested.
The Corvette was a 74 model, which was rated at 250 HP. The 75 model was less.
Exactly! Not sure about the others but the Corvette is a ’74 not a ’75. The 1975 Corvette L82 motor was only 205 net horsepower not 250.
0-60 in 7.4 s is pretty good for the ‘malaise era’.
As already mentioned, the 1975 Vette with an L82 had 205 hp. The base L48 only had 165 hp,making 1975 a low point for horsepower in a Vette. 1975 was a low point for horsepower from GM and Ford in general, much of it due to the restrictive catalytic converters that were introduced that year.
FWIW, C/D tested a 1975 Vette with an L82. It ran 0-60 in 7.7 seconds and through the 1/4 mile 16.1 sec @ 87.4 mph. Top speed was observed at 129 mph
You can also tell it’s a ‘74 by the seam in the rear end cap/bumper
All of the cars on test were ’74 models (or ’73, in the case of the Dino) — I looked it up, and this article originally ran in the February 1974 issue of Road & Track
I must have scanned this from a Buyers Guide that was dated 1975, or? The compact station wagon comparison had the same issue. I’ve corrected the dates now.
Given the lack of any commentary, I must have thrown these together in haste at the time.
I assumed the actual scans came from a later compilation published in 1975, probably collecting articles from the previous calendar year.
So the SL was slightly more expensive than the 246…didn’t expect that.
Stupid inflation, $64,012 just barely gets you in a new Corvette alone now!
I wonder if you could still get an open-top Corvette, Porsche, Mercedes, Ferrari, and Jaguar for $640, 120 today.
An interesting question – I can supply the answer in the case of the MB. I bought a 1977 450SL early in 2017, and it is very, very similar to the 1975 tested here.Most of what the reviewers said rings true today, though of course the car seems primitive in a world 43 years on.
In June of 2017 I bought a 2017 Mercedes SL550 roadster, a lineal descendant of the 450SL and it occupies the same market niche, though the argument could be made that it is more sporty.
I am not sure what the cost of this would have been in the US, but in Canada where I live, it was roughly $135,000 with an MSRP of $153k- against an inflation adjusted $17,000 1975 dollars figure of $77,500 in the US. I would guess the car in the US would have been $115-$125K so quite a bit above the inflation adjusted cost of the ’75. Now, compare the content, capability and performance of the two cars and you see where some of that price difference lies.
My late father remarried in 1979, a year after being widowed, and within 6 months had purchased for the new wife a new 1980 450SL, which was (with leather and alloys, like the car tested here) $37K. Such a vast increase – more than doubling in 5-6 years – was presumably attributable to more than just inflation and exchange rate fluctuation.
Concerning inflation and the generally undesirable impacts it has, care to consider what incomes were like in 1975? Incomes tend to inflate as well.
Fascinating- love those reprints. I couldn’t help but notice, though, that the Corvette was the fastest in the 0-60 and 1/4 mile, 2nd in the slalom, cost 2/3rds the price of the closest competitor, and still got panned for being crude and unsophisticated. Some things haven’t changed in the past 40 years (grins).
I do have to add that the loss of the chrome bumpers took away a lot of the charm those sharks had.
The ’74 Vette tested here was crude, with a chassis dating back to 1963, but I agree it did perform well under test conditions on smooth roads. That said, I’d argue a modern Vette is not crude anymore. Ever since the revolutionary C5 Vette, it has been getting progressively better and no longer crude like Vette’s of the past. The current Vette is world class and just an amazing performance machine period. It does everything well and without any major compromise.
I loved Corvettes even though I never really considered buying one. While shopping for a car one time I looked at a C3 at the used car lot and noticed it had a 4sp. Rounded up a salesman and took it for a drive. Seriously, don’t meet your heroes.
Nice to read a comparo that has nuance and real-world driving considerations. Today’s R&T and C/D are about little more than lap times and complaining that other cars are not Porsches (or in C/D’s case, Nurburgring Camaros).
And how about the value change over time! Of course the Ferrari wins, followed by the Porsche, but the Merc looks like the biggest-dollar loser. I suspect that a groovy guy like our test pilot still has the Vette.
“Today’s R&T and C/D are about little more than lap times and complaining that other cars are not Porsches (or in C/D’s case, Nurburgring Camaros)”
You have a good point here. I would go even further to add that car magazines (at least those that I have access to) are way disconnected to most people’s tastes and expectations about cars. How many testers have complained that cheap small economy cars have “hard plastic panels” and other smart conclusions like that?. What one can expect from a vehicle like that? Connolly leather? And why should I care about road tests on every new special ultra limited edition of every sports car in the market ? Maybe they are targeting 14 years old kids and totally gave up adult readers.
Five exotic open sports cars. Mmm, I’d classify the 450SL as a personal sports coupe but not a “sports” car. I have personal experience with two of these cars and indirect with one. My father owned a 72 911E Targa and a 74 450 SL which are close enough for comparison. These two could be the 1960 Corvette vs. the 1960 Thunderbird in that maybe on the same spectrum but opposite poles.
The Porsche was my idea of a sports car. Taut, quick, and somewhat noisy. Aren’t open sports cars supposed to be noisy by description? So I am OK with that just as I would in an MGB or Fiat 124. The car has that unique sound that only a 911 can have both inside and out. One could hear this car almost 100 yards away as my father came up the long road to our house. Also had that unique rear engine 911 smell.
The 450 SL was a very quiet car on the road. It is more luxury than sports and appeals to a completely different clientele. Being front engine it was more familiar to me on the road. The Porsche was news to me on some certain curves around where I lived. Luckily I stayed on the road, that first time, otherwise I wouldn’t be writing this today. What I recall most was the seating between the two. No bolster on the 450SL and the seat was fairly flat so on hard braking one would slide forward towards the wheel. However, plenty of leg room which the 911 didn’t have considering my 6’1″ height. The shifter would always hit my right knee as my right knee was right into the console. So the 911 was good for a short hop along Skyline Blvd. down the San Mateo Peninsula while the 450SL was the long distance tourer.
As for the Corvette, a friend had a 72, which had more power for going flat out but the handling and suspension would be primitive against those other two foreign makes. Maybe the best America could offer at the time although if I had to choose American then it would have been a properly set up 1966 Shelby GT350.
Imagine if they knew THIS was gonna be available 40 years later – with a 0-60 in the low 6’s and 35mpg.
You get the impession that the reviewer believes that the Ferrari actually is more reliable than the Mercedes!
Interesting in deed…!
Some quite-surprising findings in this, but the most notable thing to my eyes is that the 20 y.o. Chev small block, all iron, pushrodded, one carbie and less than 400cc bigger than the 2 y.o. twin cammed, all alloy, four-carb uber-swish Jag, puts out the same power, and on regular fuel too. Just why was it that the sophisticated designs were so incompatible with US emissions stuff? You’d surely think the cruder design would suffer a good deal more. I get that higher compression (because of lower capacity) might create more difficulties till electronic injection etc began to even things out (hence the low comp on all the Euro ones here), but the Chev is 9.0:1 – and the Jag reduced to just 7.8:1. Doesn’t make any obvious sense, but at minimum, it surely shows what an essentially fine thing the GM engine really was. I don’t like the ‘Vette of this era one bit, but it’s also intruiging to see that if it had had the normal suspension, it would’ve given all the Euros here a good haircut – or at least a good shave – on any circuit and in the real world. In a considerably cruder fashion, yes, but a haircut is a haircut.
Of course, if I was an actual buyer in ’74 for this quartet, I’d pay three times the Chev’s price just to see that gorgeous Fazza daily, and daily hear it sing – well, alright, on the days it wanted to, then.
Keep in mind that the Jag V12 was really not designed as a high performance engine. It had that less-than-stellar “Heron” cylinder head with dished pistons, probably rather small valves and rather restrictive and long intake ports. All of this was of course very different from the classic XK engine with its DOHC and hemi heads. This explains why the original non-smogged V12 only produced 272 hp, slightly more than the XK’s 265 hp.
The V12 was originally conceived as a DOHV hi-po engine, but late in the game it was drastically dumbed down to do service in large and heavy saloons, hence the completely redesigned SOHC non-hemi cylinder heads.
It’s a classic example of the confused thinking that was starting to permeate the British industry at the time, but then we can argue that the Jag’s future was more in line with MB’s and not serious sporting cars.
As to the Chevy V8, well its cylinder head was brilliant from day one despite its plebian intentions, and it was carefully developed from then on, along with its camshaft profiles, intakes and exhausts. Despite being de-smogged heavily, it could still breathe, for the time being. Unfortunately that would get worse over the next some years. In fact in 1975 the max power from the 5.7 L V8 was down to 205 hp, close to the low point (200hp in ’82) in its long and illustrious career.
The V-12 valves were 1.625 intake, 1.36 exhaust. The Heron heads were selected primarily for better emissions performance, although Jaguar also found that they produced better mid-range torque than a DOHC hemi design, which they also considered.
One question – I don’t know whether this is generally the case, but it seems like American manufacturers have often skimped on shock absorbers, leading to poorly damped suspension. Seems like this is the case here with the Corvette. Could the issues with the suspension be helped by just putting on some high quality shock absorbers? Realizing that the spring rates were still pretty stiff, and that would be harder to fix.
Also, my understanding is that a lot of the choices for engine size in Europe (Japan I don’t know about) were really driven by tax rates that were based on engine capacity – and in some cases such as England that formula solely considered the cylinder diameter and number of cylinders – leading to excessively long-stroke engines.
The small-block Chevy V-8 as I understand it made more power, was lighter, and could be just as economical as the Jaguar 6, but the Jaguar 6 was smaller in displacement, and so taxed at a much lower rate.
Yes, American manufacturers tended to skimp on shocks, and it used to be one of the top recommendations to improve handling by the magazines. Eventually that changed as handling quality became a more competitive factor.
The British tax base don bore size actually ended in 1947, replaced by a flat tax in 1948, so the reason many British engines were undersquare after the war was because the manufacturers had invested in the design and facilities to make them that way. But new designs after 1948 commonly weren’t undersquare; UK Ford’s new “Kent” ohv four was one of the most oversquare engines ever built.
Taxes on displacement in Europe varied by country, so that was not a consistent thing. The one consistent was high fuel prices, so smaller displacement engines were invariably more commone there for that reason alone. Also, European cars rarely had lots of power-robbing accessories like automatics, a/c, etc., so they did ok with their smaller engines.
Since the UK had a flat tax since 1948, your comparison of the XK engine and the Chevy V8 are not relevant. Which explains why American V8s found their way into several British cars, like the Bristol, Jensen and others, and were highly desirable as a consequence.
The XK engine was designed to be built in 2.4 L and 3.4L versions originally, so they only had so much room to grow displacement, 4.2 being the maximum for that design. That’s why they built the V12, as a larger engine for the increasingly heavier sedans.
The shocks on my Dad’s 1979 Chevrolet Impala were limp and weak from new. They lasted all of 30,000 km, when they were replaced by quality gas shocks. It transformed the way the car drove, making it much more buttoned down and controllable.
In those days it was common for new car buyers to change the shocks on their new car. Tires were another place Detroit skimped and were often replaced with the shocks.
Thank you!
Didn’t know that the UK went to a flat tax in 1946! I knew it happened at some point. The Jag engine is still a long-stroke design, is that partly because development began during the war?
Still, all the European makes, but especially Britain as I understand it, would be export-focused, so anything that made their cars less appealing (e.g. large taxable displacement) anywhere would be a consideration, I would think?
In any case, interesting to note that the Chevy V-8 here gets better fuel mileage than the Jag, and not that far from the Mercedes, though it has the benefit of (early) fuel injection.
Harley has usually skimped on good shocks too, probably for similar reasons – they figure most customers won’t care/notice, and those who do will go out and get what they want.
It was in 1948 that they went to a flat tax.
In terms of the development of the XK engine, it’s hard to say whether the outgoing tax had an influence or not. Oversquare engines were simply rather rare at the time. The VW engine was quite unusual in being oversquare when it was designed in 1936, and that turned out to be very advantageous in allowing it to run at max. power indefinitely with less wear and tear.
FWIW the 2.4 L version of the XK engine was oversquare, because it was created from the 3.4 by shortening the block and stroke.
I assume you know that very many modern engines are also undersquare? Like the classic Honda fours? And many others. Turns out that undersquare engines are easier to desmog, and their torque curves are advantagous, and their inherent breathing lomitations are readily overcome by 16 valve heads.
Walter Hassan said it did, although it was not the sole consideration. He said:
“[T]he XK engine was designed at a time when a now-obsolete form of taxation was in vogue, where the tax was related to horsepower. The tax was calculated on the bore size and this, of course, had a paralyzing effect on engine design in Great Britain until 1947, when the law was changed. … The pre- and immediate postwar Jaguar push-rod 6-cyl engine of 3 1/2 liter capacity was, at the time, considered an excellent engine of its type. The crankshaft was undoubtedly a very satisfactory component and, therefore, provided a sound basis around which to design the XK engine. The cylinder proportions were then fixed at 83 mm bore X 106 mm stroke for 3.4 liters.”
(This is from his 1972 SAE paper on the V-12 engine, which provides a detailed and, given the source, presumably authoritative discussion of Jaguar’s thought process with regard to the development of the V-12.)
Thank you! No I guess I hadn’t kept track. But it makes sense that, if one is seeking thermodynamic efficiency and clean combustion, the ideal configuration might be different than the classic (for racing) oversquare design, which is optimized for creating the maximum amount of horsepower for a given displacement and/or weight.
I’d still take the Corvette. And a set of Konis.