Manufacturers lying to consumers to sell products.. ya not possible at all. Rofl 🤣 😂

 

Yet the numbers don't really bear that out. Consider a Cadillac Eldarado with the 500cid engine. In 1970 it went from a rated 400hp with 10:1 compression to 190hp in 1975 with 8.5 compression, and a corresponding loss of 200 ft-lbs. However, in that time the 0-60 and 1/4 mile times only dropped by about 14%, and most of that could be attributed to the compression drop and increased weight due to the 5mph bumpers. If the horsepower really was cut in half, the 0-60 times would have been a lot slower in the detuned version.

What it says to me is that pre-1972 the HP numbers were coming from the Marketing department, not the Engineering department and bore no resemblance to reality. We see that in Jaguar as well, the "265hp" 3.8 litre E Type was really about 180hp at the flywheel. The most powerful production version of the 4.2 was the big valve, European market XJ6 with EFI that produced a real 205hp, not even close to 265hp.

 

There is more than a plenty of dyno time been done on correct factory restored cars/motors from that era, as a lot of folks have wondered what they actually made vs claims.
Lots of such on youtube, you just have to sort of average the results to filter out bias a little. I've found it pretty interesting to see who was sandbagging and who was
overly optimistic after all these years.

Going from 7ish seconds to closer to 12 in 0-60 sounds like a proper smog era hit to me. A young me would have been thrilled at a mere 14% hit.
Prior to losing the lead in fuel and having to meet smog requirements and have all the archaic systems that they came
up with attached, getting 3-400 hp out of a v8 wasn't hard at all for several decades. They drove nice too, plenty smooth in the heavy full frame chassis they were in,
tons of power without the need for huge RPM and the engineering to support it. Pleasant the same way a good v8 is today. Hence the LS showing up everywhere you turn.

 

They very much should have upped the displacement, or something. At least for the smog market, or after a few years when the neighbors were making progress.

Modern EFI has been a godsend for driveability, power, mpg, smog, longevity, all of it. Last year Pop and I put megasquirt on a 63 Corvair Turbo (another really neat motor that makes uninspiring power
these days) and the drivability and useability of the thing is light years over the carb even with just a basic guesstimate fuel map. I've had a lot of carbs and was the "carb guy" for a long time but
if I never see one again it'll be too soon. The Solex 4v Mercedes stuck us with in the USA finally broke me, I put up with one of them daily for two years and finally sold it mostly because of that carb. Noooo more lol...
One of these days I'm going to fuel inject my lawn mower, then I'll be completely carb free.
My first non-carb experience was with bosch CIS and CIS-E, Mercedes hung onto that excellent system for ages, the various other germans taught me the later Jetronic/Motronic
stuff so I've been pretty happy with EFI since I came across it. The early TBI stuff was really simple, we had a Holley Pro-Jection setup on an old motorhome that had a Toranado
FWD v8 drivetrain ages ago, even that thing picked up 2mpg lol.

 

In the late 70's and a bit into the 80's the v12 seemed more reasonable, it's power output
if not fuel mileage, but it had "enough" and a little exotic flair.
I'm talking about in the US where it's 260, basically. Post HE anyway.
Toward the later 80's and certainly by 90 it wasn't comparing so well to what
all else was on offer. They seem to have done very little to upgrade the thing
until right at the end. But it was cheap, relatively speaking.
I suspect if they had gone 6L, or more, three or four years earlier and leveraged
some of the tech available at the time for the injection system and borrowed an OD
trans from GM they might be looked on a little more favorably. Or have sold better.


It would be kind of fun to build just that, actually.
Hmm...

 

The US EFI version from 1975 to 1992 made 260 hp. The HE* with 11.5-1 compression made the same horsepower as the earlier 7.8-1 compression engine. On carbs The earlier V12 made 237 horsepower. (7 more than the 454 did ) But Group 44 with just cams and pistons bumped those carbs up to 450 hp. And using SU’s Huffaker make 470 hp.
Meanwhile in England the 1980 V12 had 10-1 compression and made 322 horsepower. Stone stock. While the 1980 Corvette was making ?
* yes power the same with either 7.8-1 or 11.5-1 compression.
The reason for the HE was to Help Emissions California implemented new smog rules for 1980 and the earlier engine was too dirty smog wise.
If you look at the timing of the earlier engine and then check the timing on the HE you’ll understand why higher compression didn’t make any more power.

 

The factory 6.0 cars do have a GM OD transmission. The reason they didn't do it sooner was there wasn't a 4 speed that could handle the V12's power and torque. Neither the Ford AOD or the the GM 200R4 or 700R4 or any of the ZF models could do it reliably and with the needed refinement.

Jaguar engineering was really stretched in the 80's designing and building the XJ40 sedan. That was their make or break car and it was using up all the available resources. They also designed a completely new engine (the AJ6) in that time and it was becoming the volume seller in both the sedans and XJS in the later 80's and 90's.

Jaguar produced a new car and a new engine with about 250 Engineers. It took 6000 Engineers for Lexus to do their first car. It's amazing what Jaguar was able to do with so little, but you can see why the V12 was left alone - sales were picking up considerably through the 80's, it worked well and there was no real pressing reason for change. Lincoln and Cadillac mainstream models were not offering much over 150hp and Jaguar had a V12 doing 262hp. Even a Ferrari 308 was barely over 200hp. They didn't need anything more to win an 80's horsepower race.

 

Jaguar was using GM transmissions. When GM came out with an overdrive automatic Jaguar used them.
If you look Jaguar was always ahead of GM on EFI technology. EFI was First introduced in 1975 and about every 2 or three years it was updated AJ6 engineering breaks down which version was used which years. When OBD2 became the Standard Jaguar had it even though they had been bought by Ford and had manufactured their last V12.
The 6.0 liter was intended to be used earlier but delayed by Ford. Actually Sir William Lyons had designed the V12 to go out to over 500 cu in. Which is what delayed its introduction.
First conceived in 1954 by the early 1960’s they were building prototypes at 5 liters and they made 502 horsepower. Once Ford went after Ferrari Jaguar left Ford and Ferrari fight it out.

 

That light weight 6 with 4 valves per cylinder is competitive power to weight with the V12. If you don’t lift the hood it’s hard to tell. Plus it’s a lot more fuel efficient. Well I need to be more careful. It’s competitive with the 5.3 not the 6.0
Plus there is a factory optional supercharger available for that 6 cylinder that really will beat the 6.0 lite. Oh and the V12 was originally designed by just 2 engineers. Both versions. The early 5.0 liter Quad cam version that made 502 horsepower
and the later SOHC version that original came out as 5.3 and was designed to go over 8 liters.

 

Little to no HP but plenty torque to be a good time. The HE was a big step in the right direction and commendable, for the day,
that they got it to work with so much compression.
That's another revalant-ish point, hp is functionally irrelevant, especially to Americans (whether we know it or not).
It's torque, preferably starting down low, that most everyone wanted for ages (and no small number now).
Which is sort of the opposite direction of going with a many cylinder'd, high revving engine.
It was a European mindset, and I've enjoyed/tolerated no few of them over the years that did just that.
There in the 80's BMW figured out that while the M20 was a lovely motor, it was an annoyance to drive in a lot of cases
since nothing interesting happened till 3500rpm or so and the rather large buying audience of yuppies wanted to just stick
their loafers in it at will and accelerate, which only happens when you have gobs of torque at any given time/rpm available.
And it was all but hopeless at stoplight drag races, which is something
else near and dear to the American buying public's heart. At least back then.
They developed a low revving E(efficiency) "torque" motor that at once got really great MPG and felt like it was a liter larger than the venerable
M20 in normal use. As long as you didn't really expect it to rev out and make power.
We are mighty short on autobahns, or good roads at all, over here despite the land area unless you're lucky, so high revving stuff has always
been a hard sell to the numbers of people you'd need to sell cars to over here to turn a profit.
I still see what are now retro-reviews where young car people call the xjs slow, or are at least surprised it's as anti-climactic with a v12.
They usually comment on the sound and feel, the jet-engine-ness, which is certainly a thing, and that it gets out of it's way ok, but there's nothing there to wow them.
Torque would. But that's not really it's game. So 40 years later it still feels underpowered, weight isn't helping, still, and the brave, proud and
few are still looking for ways to make it faster, and there just aren't any that are economically in keeping with what the cars are worth.
These cars, as beautiful and elegant and mechanically fascinating and unique as they are, especially with the low production, should be
worth a TON of money. But they aren't(at least in the USA), and I think the learning curve, repair grief and lack of payoff for the effort keeps them cheap by
and large. I think they are wonderful or I wouldn't own one, but I can see why most people don't, even car enthusiasts.
Automotive folks are a fickle lot.


But to your point past my ramble: exactly.
It was plenty favorable in the late 70's and into the 80's.
But it did not exist in a vacuum despite how it seems to have been treated,
everyone else in the world was moving right along.
By 84, to borrow your example, the Corvette was doing the same performance
with 60 less hp, because of lightness and an engineering budget. And that wonky
crossram injected 84 350 felt strong doing things we usually do with cars, because of torque.
Few years later the LT1 came along, and everyone in Europe and Asia
figured out 4 cams on a v8 is a good recipe for grown-ups, or two on a six with a turbo for the kids.

And that's perfectly okay. I'm not privy to any of the internal goings on and business goals and such of the time, I've no doubt they
could well have tacked another 50hp onto the thing every other year if they'd wanted, technology was progressing pretty hard back then.

I really don't know why it didn't sell any better or wasn't any more well received when it was young, despite thinking it should have had more
power. But it did not.

 

I've read how small their staff was, it shows in some areas lol...
It was probably a good call putting the effort into the xj40.

 

The few XKR with the blower six I've been around were very pleasant, as was the later 8 even if it did reek of ford-esque-ness.

 

the Jaguar V8 version was already in Pre-production when Ford came into the picture. While I’m sure some of the plastics were the result of Fords input.
Ford’s cost accounts did have a major impact on our V12. There were two batches of the 6.0 liter made. Yeh! for cost reasons Engines were batch made. The first batch the crankshaft and rods was forged of EN 30 Steel and then heat treated after all the machining was done. The 2nd batch used Fords Sintered Iron process out of Germany.
For those keeping track that occurred in 1995. That is sometime late in 1994 the crankshafts and rods stopped being forgings and became typical Sintered Iron. Luckily Jaguar engineers way overbuilt the engine and there has never been any problems with Jaguar’s in that regard. We racers prefer the 93&94 versions but the later ones are fine for ordinary mortals. Big silly grin

 

Sintered iron rods were pretty common by then, the v8 in the Porsche 928 used them to good effect early on(late 70's maybe?), and it wasn't because they couldn't afford anything else I'd be willing to bet. They aren't necessarily a downgrade compared to forged, especially if the forging design and process was an older one
and the sintered iron was well engineered from modern experience. Often times you can find a cheaper way to get the same or adequate performance from a thing via technology for mass production vs the brute force approach of just using the strongest heaviest thing available. If you can afford it.
If such start breaking chronically it's usually a sign an error was made. If not, success.

 

Once I see NASCAR, INDY CAR NHRA or Formula1 start to use Sintered Iron I’ll accept your statement. Personally I’ve built offset ground Jaguar V12 crankshaft forged from EN 40 steel and hardened without a problem or consequences.
However I did mention Sintered Iron is perfectly acceptable for typical street usage. And it is better than cast Iron.

 

Typical street usage no doubt qualifies what relatively few 6L v12's were produced. Can't blame someone for trying to make a buck if there were no ill effects.

 

I believe the first batch was something like 3500 engines and the second batch was only 1500. Really performance wise the 6 cylinder wasn’t that much inferior to the V12. The difference in weight offset the slight power advantage. Plus it didn’t terrify mechanics as much.

 

I know there were certainly rough times but it's a credit to Jaguar that they managed to stay in business with so relatively few sales and modest prices.

 

Sounds like things are really marginal now. I heard that global sales is under 5000 cars a month.
They are going to eliminate up to 50 UK dealers leaving only 20 and price themselves around Bentley prices to survive.
I’ve been a life long racer of Jaguars. I’m sad to see it coming to this.

 

Right now Jaguar are scheduled to stop producing I.C. cars in late 2023/early 2024. Many fewer that 5000 per month are being made, and the few that are seem to be electric or hybrid suv type models.
The company has just parted ways with yet another chief, and a stand-in is holding the fort. The announced plan from the outed chief was all electric from 2025, which is why output now is so low.
AFAIK, no plans for market positioning have been announced, but Jaguar as a brand is not highly rated or highly recognised by the under 55 age group. As an example, when I joined the JEC fulfilling a lifetime ambition to have an XJS and aged 50, I was bang on the average age of the club membership. 25 years later the average age of members has nearly kept up with mine!

Basically, and sadly, the company has lost its way and does not really know what to do. In its heyday it did things no other company could, at a price no other company could match. The company, to survive commercially, has to somehow differentiate itself again; what that might be I have no idea; but competing head-on with BMW and Mercedes Benz will not work and has not worked for the last 15 to 20 years.