RE: Jaguar XJ-S V12 | The Brave Pill
Discussion
With regards to the finesse of the various engines.
I went from a series III 4.2 XK engined to a 4.0 AJ6 engined XJ40 Sov back in the day. I tried a few 3.6 XJ40s as they were more in my price bracket at the time but couldn't make myself buy one. The 3.6 engine in the XJ40 sounded and felt like a cement mixer full of nuts and bolts compared to the old XK 4.2 engine it replaced. I just couldn't buy one.
Eventually I found a 1990 (H343 YWD
) 4.0 XJ40 cheap enough for me to afford. The engine in that was sooo much more refined than the earlier 3.6s. I kept that car for 10 years.
A year or so later I also bought a 1990 3.6 XJS. I was hesitant about buying it based on my previous experience of that engine, but in that XJS it seemed way better than how it had been in the XJ40. I suited the car very well and maybe Ford had done some work in it or the car to improve NHV. I sold that car after 18 months as I could see rust under the paint and it blew a piston for no apparent reason.
I tried a V12 XJS at the time, found it underwhelming compared to the 3.6. Was expecting great things, but it seemed barely smoother and certainly it felt no faster. And when you lifted the bonnet , the horrendous plethora of random pipes all over the engine immediately scared me right off!
I went from a series III 4.2 XK engined to a 4.0 AJ6 engined XJ40 Sov back in the day. I tried a few 3.6 XJ40s as they were more in my price bracket at the time but couldn't make myself buy one. The 3.6 engine in the XJ40 sounded and felt like a cement mixer full of nuts and bolts compared to the old XK 4.2 engine it replaced. I just couldn't buy one.
Eventually I found a 1990 (H343 YWD
) 4.0 XJ40 cheap enough for me to afford. The engine in that was sooo much more refined than the earlier 3.6s. I kept that car for 10 years.A year or so later I also bought a 1990 3.6 XJS. I was hesitant about buying it based on my previous experience of that engine, but in that XJS it seemed way better than how it had been in the XJ40. I suited the car very well and maybe Ford had done some work in it or the car to improve NHV. I sold that car after 18 months as I could see rust under the paint and it blew a piston for no apparent reason.
I tried a V12 XJS at the time, found it underwhelming compared to the 3.6. Was expecting great things, but it seemed barely smoother and certainly it felt no faster. And when you lifted the bonnet , the horrendous plethora of random pipes all over the engine immediately scared me right off!
My old boss had a six litre XJS he bought off Tom Walkenshaw. It went like a train but had a tendency to throw up dashboard warning lights when nothing was actually wrong. Conversely no warning lights came on when something actually was wrong....
Some staff members were allowed to drive it. Just after it had been smartened up one slid it into a kerb and pranged the front spoiler. He immediately reported it to the boss who said no problem, I can blame you instead of the dog I ran over last week.
Some staff members were allowed to drive it. Just after it had been smartened up one slid it into a kerb and pranged the front spoiler. He immediately reported it to the boss who said no problem, I can blame you instead of the dog I ran over last week.
alabbasi said:
That's a heck of a statement. The BMW M30 engine was probably the best engine BMW ever made. I know several cars with close to 400k miles on their original engines.
If jaguar made a better engine. They'd have a different reputation today.
It was a good engine, just very out of date by 1987. If jaguar made a better engine. They'd have a different reputation today.
Jaguar steve said:
What effort was that then?
From launch of both cars and up to 1990 the 3.6 AJ6 engine in the XJS was exactly the same as the 3.6 AJ6 engine in the XJ40.
We are talking about the 1986 XJ40 unit compared to the 1983 original. From launch of both cars and up to 1990 the 3.6 AJ6 engine in the XJS was exactly the same as the 3.6 AJ6 engine in the XJ40.
Development is the word. In detail;
- Improved balancing tolerances
- Closer bearing tolerances
- Crank damper balances as one with the TDC ring and pulley
- Revised pistons
- Improved chain tensioners
- Larger cam lobe base circles
- Lighter steel cam buckets replacing iron ones
Period tests of the XJ40 commented on how much better it was than the original.
Edited by Touring442 on Sunday 25th August 16:05
Touring442 said:
It was a good engine, just very out of date by 1987.
The M30 had mechanical lifters, I suspect that many out there were running around with valves that were out of adjustment. This is a super easy remedy and once adjusted, they're very smooth engines and run like sewing machines. My 85 745i has a variation of the M30 motor that was turbo'd from the factory. It has close to 300k miles on it. I know several people who've turbo'd those engines to make close to 500hp.As far as 3.6 vs 4.0. My 3.6 with a 5 speed has a 4.0 engine so I can't tell you. I have had cars with the old XK engines are they are course. Kind of like the Mercedes Benz M110 six. My 5 speed XJ-SC is very smooth and very quick and compared to the V12, and super easy to work on.
The most important thing about successful v12 ownership is that you've either got to have deep pockets and a passion for the car, or you enjoy working on challenging cars. It's not enough to just enjoy working on cars because everything is much harder to access and takes longer to perform, by an order of magnitude.
I just did a deal on a building and will need to sell some cars to pay for it. Anyone who wants to do a group test. I'll be selling this XJ-SC 5 speed, along with an 88 BMW M5, 85 745i, 90 300SL-24 5 speed and an 81 280SL 5 speed (probably the 94 6l V12 XJS Convertible too).
Edited by alabbasi on Sunday 25th August 16:20
alabbasi said:
The M30 had mechanical lifters, I suspect that many out there were running around with valves that were out of adjustment. This is a super easy remedy and once adjusted, they're very smooth engines and run like sewing machines. My 85 745i has a variation of the M30 motor that was turbo'd from the factory. It has close to 300k miles on it. I know several people who've turbo'd those engines to make close to 500hp.
The M30 was a great engine in 1968, very good in 1978, out of date by '88. Iron block so it weighs a ton, two valves per cylinder and not wouldn't pass emissions laws for much longer. 1989 saw the 4.0 Lexus V8 which would cut the BMW's head off and **** down its throat. Power, torque, economy and refinement were in another league. Time moves on. Touring442 said:
The M30 was a great engine in 1968, very good in 1978, out of date by '88. Iron block so it weighs a ton, two valves per cylinder and not wouldn't pass emissions laws for much longer. 1989 saw the 4.0 Lexus V8 which would cut the BMW's head off and **** down its throat. Power, torque, economy and refinement were in another league. Time moves on.
Those are motoring magazine statistics and not real world experiences. By the time Lexus came out with the V8, BMW already had a V12. You might as well be comparing the Costworth 2.0 with a Rolls Royce 6.75l. It's apples to oranges. As far as iron block, weight, # of valves, bla bla bla. I've owned and driven a lot of cars and by far the most fun car that I've own was my E12 81 528i with a 5 speed. Might not be the fastest but it was blast in every gear and in every corner.
Today, I'd pick a BMW with the M30 engine over the M60 that replaced it or the Lexus LS400. I think that you'd find that the sentiment is much the same in the Jaguar circles when it comes to the AJ16 vs the early AJV8's that replaced them.
Edited by alabbasi on Sunday 25th August 17:30
alabbasi said:
Those are motoring magazine statistics and not real world experiences. By the time Lexus came out with the V8, BMW already had a V12. You might as well be comparing the Costworth 2.0 with a Rolls Royce 6.75l. It's apples to oranges.
As far as iron block, weight, # of valves, bla bla bla. I've owned and driven a lot of cars and by far the most fun car that I've own was my E12 81 528i with a 5 speed. Might not be the fastest but it was blast in every gear and in every corner.
M70 V12? What you mean that 14 mpg antique with no real power advantage over a 4.0 V8? As far as iron block, weight, # of valves, bla bla bla. I've owned and driven a lot of cars and by far the most fun car that I've own was my E12 81 528i with a 5 speed. Might not be the fastest but it was blast in every gear and in every corner.
528i? They were okay, my M535i was faster. :-)
The M30 was old, heavy and had poor fuel efficiency. It was replaced by something better, as was the M10. It happens!
Touring442 said:
528i? They were okay, my M535i was faster. :-)
The M30 was old, heavy and had poor fuel efficiency. It was replaced by something better, as was the M10. It happens!
Yeah my M5 and M6 are faster than your M535i but who cares. It's still the best engine BMW ever built. I'm not sure how the M10 replaced the M30. I'm pretty sure it was around before Charlton Heston played Moses in a movie. Maybe even before Moses himself.The M30 was old, heavy and had poor fuel efficiency. It was replaced by something better, as was the M10. It happens!
alabbasi said:
Those are motoring magazine statistics and not real world experiences. By the time Lexus came out with the V8, BMW already had a V12. You might as well be comparing the Costworth 2.0 with a Rolls Royce 6.75l. It's apples to oranges.
As far as iron block, weight, # of valves, bla bla bla. I've owned and driven a lot of cars and by far the most fun car that I've own was my E12 81 528i with a 5 speed. Might not be the fastest but it was blast in every gear and in every corner.
Today, I'd pick a BMW with the M30 engine over the M60 that replaced it or the Lexus LS400. I think that you'd find that the sentiment is much the same in the Jaguar circles when it comes to the AJ16 vs the early AJV8's that replaced them.
That BMW M70 V12 was disappointing, it didn't match the refinement of the Jaguar V12 that was 15+ years old at the time. I suspect it was more marketing driven than engineering driven given the mad 2 x 6 pot and one to tie them together three ECU setup it used.As far as iron block, weight, # of valves, bla bla bla. I've owned and driven a lot of cars and by far the most fun car that I've own was my E12 81 528i with a 5 speed. Might not be the fastest but it was blast in every gear and in every corner.
Today, I'd pick a BMW with the M30 engine over the M60 that replaced it or the Lexus LS400. I think that you'd find that the sentiment is much the same in the Jaguar circles when it comes to the AJ16 vs the early AJV8's that replaced them.
Edited by alabbasi on Sunday 25th August 17:30
One thing that isn't magazine stats is just how far ahead of every other luxury car powerplant that Lexus V8 was at launch, while avoiding all the durability woes that plagued GM, Jaguar, and BMW with their own quad cam "modern" V8 engines that eventually brought them up to rough parity with the Lexus.
Given the option of running a 1996 AJ16 X300 Jaguar or a 1997 X308 AJV8 at this point I'd go for the AJ16 as it gives a much more "classic" feel, which is what I'd want from a 20 year old Jaguar. In 1997? I'd have been down the dealer to trade in my X300 in a shot.
stickleback123 said:
That BMW M70 V12 was disappointing, it didn't match the refinement of the Jaguar V12 that was 15+ years old at the time. I suspect it was more marketing driven than engineering driven given the mad 2 x 6 pot and one to tie them together three ECU setup it used.
Yep, V12 was new to them and it was a struggle. The V8 that followed was also plagued with much of the same issues as the AJV8 stickleback123 said:
One thing that isn't magazine stats is just how far ahead of every other luxury car powerplant that Lexus V8 was at launch, while avoiding all the durability woes that plagued GM, Jaguar, and BMW with their own quad cam "modern" V8 engines that eventually brought them up to rough parity with the Lexus.
Absolutely, when Toyota introduced that it, they had manufacturing down to a fine art and copied the best from every manufacturer to make a better all around car. It's kind of the same way that Samsung now owns the TV and Cell Phone business when you would have not considered either 20 years ago.It did not take long for everyone else to catch up however. The Mercedes M119 engine is in my opinion a better engine and the W140 is a better car.
stickleback123 said:
Given the option of running a 1996 AJ16 X300 Jaguar or a 1997 X308 AJV8 at this point I'd go for the AJ16 as it gives a much more "classic" feel, which is what I'd want from a 20 year old Jaguar. In 1997? I'd have been down the dealer to trade in my X300 in a shot.
Absolutely, that's progress. We're discussing these cars today and not when they were new. In 1993 the Cadillac NorthStar engine was a thing of glory but I think that I would have regretted it if I bought a Cadillac DTS in 1993. In the case of the BMW M30 (or their variants) vs Jaguar AJ6, I'm comparing cars that I currently own. While on paper, more valves and an alloy head may make the Jaguar engine look better. From an owners perspective, I can debate this quite comfortably because a BMW M30 engine in a BMW chassis from the 70's and 80's is probably the most engaging car that you can own, and I say this as a Mercedes Benz guy.
Edited by alabbasi on Sunday 25th August 18:04
alabbasi said:
In the case of the BMW M30 (or their variants) vs Jaguar AJ6, I'm comparing cars that I currently own. While on paper, more valves and an alloy head may make the Jaguar engine look better. From an owners perspective, I can debate this quite comfortably because a BMW M30 engine in a BMW chassis from the 70's and 80's is probably the most engaging car that you can own, and I say this as a Mercedes Benz guy.
I agree that the M30 is a more enjoyable engine. The AJ6/16 seems to combine a head designed for high rev excitement with the bottom end of a boat engine, and exhaust manifolds that'd make even old skinflint Lyons blush. I'm not sure what the story behind the development was, but doubtless it was fraught and underfunded throughout to create such a disappointing engine from such promising ingredients. It lead a short life by Jaguar engine standards too.The entire engine was aluminium btw, not just the heads. I think they must have put slugs of depleted uranium in the casting for a laugh though, having had to move one.
alabbasi said:
Touring442 said:
528i? They were okay, my M535i was faster. :-)
The M30 was old, heavy and had poor fuel efficiency. It was replaced by something better, as was the M10. It happens!
Yeah my M5 and M6 are faster than your M535i but who cares. It's still the best engine BMW ever built. I'm not sure how the M10 replaced the M30. I'm pretty sure it was around before Charlton Heston played Moses in a movie. Maybe even before Moses himself.The M30 was old, heavy and had poor fuel efficiency. It was replaced by something better, as was the M10. It happens!
The M10 was the four cylinder from which the M30 sprang, but you knew that....?
I don't have an M535i btw. That was 20 years ago.
Mind you, compared with some of the s
t they've been making in the last 10-20 years the M30 is a gem. It is at least reliable and tolerant of neglect. I think I've had most now, 2.5 in E12 and E28, carb and injection 2.8's and 3.0 (E3 and E9) and a 3.3 in an E3. The best was probably the original 3.5, 3453 cc short stroke/big bore with L Jetronic. They were so eager to go and the later E34 type stuff was really flat in comparison.
I've not driven an AJ6 for a long time now, a 1987 Daimler. It seemed a nice unit if not as gutsy and characterful as a Series III 4.2 XK.
t they've been making in the last 10-20 years the M30 is a gem. It is at least reliable and tolerant of neglect. I think I've had most now, 2.5 in E12 and E28, carb and injection 2.8's and 3.0 (E3 and E9) and a 3.3 in an E3. The best was probably the original 3.5, 3453 cc short stroke/big bore with L Jetronic. They were so eager to go and the later E34 type stuff was really flat in comparison.I've not driven an AJ6 for a long time now, a 1987 Daimler. It seemed a nice unit if not as gutsy and characterful as a Series III 4.2 XK.
stickleback123 said:
I agree that the M30 is a more enjoyable engine. The AJ6/16 seems to combine a head designed for high rev excitement with the bottom end of a boat engine, and exhaust manifolds that'd make even old skinflint Lyons blush
While you would expect that a multi valve engine would like to rev, I don't think that the character of the AJ6 is rev happy. I believe that the red line is at 5500RPM. By contrast, my 90 300SL with the M104 straight six will red line at 7000RPM. I do like the manifold. I think that the US XK engines suffered from smog. They had something like a 7:1 compression ratio and made about 160hp. Touring442 said:
So was the 4.0 M60 V8 once the Nikasil dramas were sorted. 286 bhp and 30+ mpg on a run. Progress!.....I don't have an M535i btw. That was 20 years ago.
I don't know about that. I have a 2003 540i/6 with about 120k miles and blown timing chain guides. Sometimes adding complexity does not make things better. GM seems to do a really good job of proving this year in year out with the LS engines.You should have kept the M535i, I might have bought it from you.
Edited by alabbasi on Sunday 25th August 20:05
Touring442 said:
Jaguar steve said:
What effort was that then?
From launch of both cars and up to 1990 the 3.6 AJ6 engine in the XJS was exactly the same as the 3.6 AJ6 engine in the XJ40.
We are talking about the 1986 XJ40 unit compared to the 1983 original. From launch of both cars and up to 1990 the 3.6 AJ6 engine in the XJS was exactly the same as the 3.6 AJ6 engine in the XJ40.
Development is the word. In detail;
- Improved balancing tolerances
- Closer bearing tolerances
- Crank damper balances as one with the TDC ring and pulley
- Revised pistons
- Improved chain tensioners
- Larger cam lobe base circles
- Lighter steel cam buckets replacing iron ones
Period tests of the XJ40 commented on how much better it was than the original.
Edited by Touring442 on Sunday 25th August 16:05
I bought to replace the 40 but there's no way either came close to the wonderful zingy refinement of any contemporary BMW 6.
The replacement Jaguar V8 exists on a whole different planet in terms of power delivery and refinement.
alabbasi said:
I don't know about that. I have a 2003 540i/6 with about 120k miles and blown timing chain guides. Sometimes adding complexity does not make things better. GM seems to do a really good job of proving this year in year out with the LS engines.
The M62 was a step back. They went from duplex to simplex chain, crap guides to replace an idler gear and they ran them very hot for emissions. The 4.0 M60 was much better. The 2.5 M50 was BMW's finest engine, so reliable and they often did a solid 200 bhp once run in. The 3.0 M60 had the same 218 bhp as an M30 3.5 but not the torque.I spent three sweary hours replacing M30 exhaust manifold gaskets today. What fun! Did anyone say snapped studs?
Jaguar steve said:
Touring442 said:
Jaguar steve said:
What effort was that then?
From launch of both cars and up to 1990 the 3.6 AJ6 engine in the XJS was exactly the same as the 3.6 AJ6 engine in the XJ40.
We are talking about the 1986 XJ40 unit compared to the 1983 original. From launch of both cars and up to 1990 the 3.6 AJ6 engine in the XJS was exactly the same as the 3.6 AJ6 engine in the XJ40.
Development is the word. In detail;
- Improved balancing tolerances
- Closer bearing tolerances
- Crank damper balances as one with the TDC ring and pulley
- Revised pistons
- Improved chain tensioners
- Larger cam lobe base circles
- Lighter steel cam buckets replacing iron ones
Period tests of the XJ40 commented on how much better it was than the original.
Edited by Touring442 on Sunday 25th August 16:05
I bought to replace the 40 but there's no way either came close to the wonderful zingy refinement of any contemporary BMW 6.
The replacement Jaguar V8 exists on a whole different planet in terms of power delivery and refinement.
The improvements in refinement, power, torque, weight, power curve, warmup time, weight, and economy of the V8 are objective facts, not opinion. You don’t develop an engine based on what the team reckon is better, it’s all specified and measured against that specification.
If someone chooses to prefer an objectively worse powerplant for sentimental reasons that’s a different matter.
If someone chooses to prefer an objectively worse powerplant for sentimental reasons that’s a different matter.
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