Discussion
Jaguar steve said:
Now that would be interesting...
an immaculate series one or two with the V8 and 5 speed 'box and air con that works would be great
Racing Green have had Beecham XK's in their show room before nowan immaculate series one or two with the V8 and 5 speed 'box and air con that works would be great
They are classic XK's with modern XKR running gear
I haven't been in there for some time to see what they have in stock
Talking of Racing Green, the guys who ran the classic Jaguar Dept. left about 18months ago and have setup on their own as Windspeed Motorsport. They are in the middle of project fitting an AJ6 into a XJ Coupe, I think it was a project that started else where and has now bee brought to them to finish off.
I would have thought that the SC AJ16S would make a more interesting toy but I believe this project started off before that was practical.
I would have thought that the SC AJ16S would make a more interesting toy but I believe this project started off before that was practical.
My dad had two brand new 4.2 Mk 1 XJ6's in 1969 and 1971....The latter one being the Daimler version........ (Cost £2200 and £3000)...(The Average weeks wage was around £60).....Engines were bulletproof, although it was/is very important to change the oil and filter at frequent intervals. Timing chains were a weak point IIRC.
The 2.8 version had a reputation for holing pistons even then.
The 2.8 version had a reputation for holing pistons even then.
The 2.8 must have been a real turd to drive. I had not one but two (yeah yeah...!) 3.4 XJ's and they were pretty gutless and not really up to the task of pulling the thing along with any authority. By contrast I had an XK150S and a 1960 Mark 11 which were both 3.4's and much better. It was probably a very good engine 50 years ago but you only have to look at the engines Mercedes and BMW were building during the XJ6 era to see that the XK was hopelessly out of date. They were only bulletproof as long as they weren't driven at high speed for too long. They just weren't designed to do 5000 rpm for long period.
I never liked the XJ40, but the 3.6 engine was very good indeed and probably as good any anything the Germans made. I've never heard any horror stories.
I never liked the XJ40, but the 3.6 engine was very good indeed and probably as good any anything the Germans made. I've never heard any horror stories.
Touring442 said:
They were only bulletproof as long as they weren't driven at high speed for too long. They just weren't designed to do 5000 rpm for long period.
Errr, and how many Le Man's races did they win with the engine?They managed to average over 100MPH for 7 solid days and nights in an XK120.
They were bullet proof when they were built properly. Cost cutting measures did help them.
I believe the testing for the military version of the engine involved very long periods of running at maximum power which resulted in the fitment of self lapping valves for that version.
a8hex said:
Errr, and how many Le Man's races did they win with the engine?
They managed to average over 100MPH for 7 solid days and nights in an XK120.
They were bullet proof when they were built properly. Cost cutting measures did help them.
I believe the testing for the military version of the engine involved very long periods of running at maximum power which resulted in the fitment of self lapping valves for that version.
Yessss.......and the engines that won Le Mans were not exactly plucked from the Browns Lane production line were they? They managed to average over 100MPH for 7 solid days and nights in an XK120.
They were bullet proof when they were built properly. Cost cutting measures did help them.
I believe the testing for the military version of the engine involved very long periods of running at maximum power which resulted in the fitment of self lapping valves for that version.
It was a fine engine for it's time. But that was a long, long time ago and even Jaguar knew it had had it's day by 1968. It's certainly an engine of character and you'd leave it in an E Type or Mark 11, but it seemed such a crude old thing in the XJ which deserved a better engine. Given that you can buy any number of rusted out old XJS/XJ40's for 10 pence and a button, it seems the obvious solution to rob it's lighter, more powerful and vastly more fuel efficient engine. Well it does to me.
Touring442 said:
Yessss.......and the engines that won Le Mans were not exactly plucked from the Browns Lane production line were they?
It was a fine engine for it's time. But that was a long, long time ago and even Jaguar knew it had had it's day by 1968. It's certainly an engine of character and you'd leave it in an E Type or Mark 11, but it seemed such a crude old thing in the XJ which deserved a better engine. Given that you can buy any number of rusted out old XJS/XJ40's for 10 pence and a button, it seems the obvious solution to rob it's lighter, more powerful and vastly more fuel efficient engine. Well it does to me.
Shock horror - Jaguar specially prepare their engines for racing. Well they were still the basic XK engine.It was a fine engine for it's time. But that was a long, long time ago and even Jaguar knew it had had it's day by 1968. It's certainly an engine of character and you'd leave it in an E Type or Mark 11, but it seemed such a crude old thing in the XJ which deserved a better engine. Given that you can buy any number of rusted out old XJS/XJ40's for 10 pence and a button, it seems the obvious solution to rob it's lighter, more powerful and vastly more fuel efficient engine. Well it does to me.
Yes it was obviously dated by the late 1960's but I've never heard an XJ being described as crude and it won plenty of accolades for it's refinement.
The engines built in the Leyland era definately suffered from quality control issues but this wasn't confined to Jaguar or the XK engine. The 3.4 in particular was a poor relation to the earlier 3.4 engines.
You are proposing that it makes sense to buy an old XJS, remove the engine, remove the XK engine from the other car, carry out numerous modifications to enable the later engine to fit, dispose of the old XJS shell and the XK engine and then fit a used engine. This is obvious to you ?
I'm tempted but I think I'll struggle on with the original engine in my car. It was properly rebuilt 20k miles ago and still runs like a sewing machine.
Edited by mph on Friday 27th May 06:07
Touring442 said:
It can't be that hard - the 3.6 was used in the XJ-S for years, and that was based on a Series 2 XJ6 floorpan. Anything's got to be better than the XK engine which should have been axed after the end of the Mark 11.
I'm curious, why don't you like the engine? Just the reliability?I've had a HEV12 XJS, X308 XJR, I have an XJ6 and my friend had a 3.2 X300 XJ6 so I've got experience with most engines types Jaguar made.
Leaving aside reliability (I must admit I was under the impression the XK was bulletproof before this thread!) the XK engine is lovely. It's very smooth (with perhaps only the V12 to challenge it) makes a lovely noise (a sort of cultured whirring with a hint of intake under load, but silent at speed, to be fair they all sound lovely) and pulls amazingly well from no revs.
Everyone who has driven my XJ6 has been very impressed with how responsive it is. I have only had it to 4,000 or so rpm so far (the car is going very quickly at this point!) but it seems to rev well, and the noise just gets better. It really doesn't feel much if any slower then my V12 did.
I was genuinely surprised at how nice the engine is. It still surprises me every time I drive the car.
IMHO it's delivers a much nicer experience then the X300 3.2, which needs revving. That engine would be great in a sports car, but the XK suits the XJ6 much better. Obviously the AJ16 is more efficient and objectively the better engine.
I find this thread interesting as I'm rebuilding a 4.0 XJS currently
using the AJ6. Personally, I think I'd have preferred the 4.2 XK.
One of the concepts I have been trying to work to with this particular
car is to simplify as much as possible. Because to me, with an older hobby
car the simpler the better. To that end, so far I've ditched
the aircon in it's entirety, electric seats, mirrors, central locking,
CD changer, electric ariel and the auto has been ditched for a Getrag
from a 3.6.
I,ve kept the power rack, the ABS ( which ultimately may go too ) and the
electric windows as there is no manual system for the XJS, or that would
go as well.
I would have liked to ditch the EFI, but I can't find an aftermarket
inlet manifold to fit triple sidedrafts to the AJ6, which is available
for the XK engine. Also as the AJ6 exhausts on the opposite side to the
XK, that has been another constraint.
I actually considered going the other way to what has been suggested
here and replace the AJ6 with a 4.2 XK. That must seem retrograde to
the point of being bizarre to some people, but to achieve what I want
( simple power ) it is an option.
The AJ6 is a good inline 6 engine, but it's electronically controlled, and
whether it's 24v twincam offers any significant advantage over a
good tuned XK is debatable.
using the AJ6. Personally, I think I'd have preferred the 4.2 XK.
One of the concepts I have been trying to work to with this particular
car is to simplify as much as possible. Because to me, with an older hobby
car the simpler the better. To that end, so far I've ditched
the aircon in it's entirety, electric seats, mirrors, central locking,
CD changer, electric ariel and the auto has been ditched for a Getrag
from a 3.6.
I,ve kept the power rack, the ABS ( which ultimately may go too ) and the
electric windows as there is no manual system for the XJS, or that would
go as well.
I would have liked to ditch the EFI, but I can't find an aftermarket
inlet manifold to fit triple sidedrafts to the AJ6, which is available
for the XK engine. Also as the AJ6 exhausts on the opposite side to the
XK, that has been another constraint.
I actually considered going the other way to what has been suggested
here and replace the AJ6 with a 4.2 XK. That must seem retrograde to
the point of being bizarre to some people, but to achieve what I want
( simple power ) it is an option.
The AJ6 is a good inline 6 engine, but it's electronically controlled, and
whether it's 24v twincam offers any significant advantage over a
good tuned XK is debatable.
Edited by mikele pirelli on Friday 27th May 10:28
mph said:
Shock horror - Jaguar specially prepare their engines for racing. Well they were still the basic XK engine.
Yes it was obviously dated by the late 1960's but I've never heard an XJ being described as crude and it won plenty of accolades for it's refinement.
The engines built in the Leyland era definately suffered from quality control issues but this wasn't confined to Jaguar or the XK engine. The 3.4 in particular was a poor relation to the earlier 3.4 engines.
You are proposing that it makes sense to buy an old XJS, remove the engine, remove the XK engine from the other car, carry out numerous modifications to enable the later engine to fit, dispose of the old XJS shell and the XK engine and then fit a used engine. This is obvious to you ?
You misunderstand.Yes it was obviously dated by the late 1960's but I've never heard an XJ being described as crude and it won plenty of accolades for it's refinement.
The engines built in the Leyland era definately suffered from quality control issues but this wasn't confined to Jaguar or the XK engine. The 3.4 in particular was a poor relation to the earlier 3.4 engines.
You are proposing that it makes sense to buy an old XJS, remove the engine, remove the XK engine from the other car, carry out numerous modifications to enable the later engine to fit, dispose of the old XJS shell and the XK engine and then fit a used engine. This is obvious to you ?
Yes, of course the C and D Type engines were specially prepared. To prove that point, drive yours at 5-6000 rpm constantly and see how long it lasts before it goes bang. I don't think it will q-u-i-t-e make 24 hours.
It won accoladers for refinement 40-50 years ago. At low engine speeds it's not bad but they really don't sound too happy at 5000 rpm. Compared to other straight six engines around 40 years ago, it wasn't that good because it was old and out of date - it happens to everything eventually.
Te AJ6 gave more power and torque, along with vastly better economy and 200'000 mile longevity. That's progress and Jaguar would have loved to have had it 10 years before they did. They stuck with the old XK not out of choice but because they did not have the money from BL to replace it. Jaguar in fact started to design the AJ6 in the seventies.
Your last comment about fitting an AJ6 is a puzzling one. Rebuild a knackered XK engine or fit a good used AJ6 for a fraction of the cost and end up with a better car....? Makes perfect sense to me - it's not as if an old XJ6 is valuable enough for an engine change to affect the value, is it? As I alluded to earlier, engineers such as Harry Mundy would have loved to have had the AJ6 in the seventies XJ saloons - so why not do it now?
Do I dislike the engine? No, not at all. It has it's place, but I don't think that's in an XJ when there is something much better available for so little. But to each his own!
The AJ6 was tested as early as in the Series 2 XJ6. There isn't that much needed to do to put one in an XJ, and so far to put an AJ16S in has only cost me two 8mm holes to mount the power steering reservoir. There are no major modifications - it bolts in nicely.
I like the XK engine, its got guts, and the sound of it when pushed hard is glorious. But - I need more performance and better fuel economy than the old legend can give, without having to spend vast amounts of money on it. I'v always got at least one old XK engine lying about though... as the AJ6/AJ16 can't compare to triple SU's, chrome cam covers and the like.
Regards,
Rich
I like the XK engine, its got guts, and the sound of it when pushed hard is glorious. But - I need more performance and better fuel economy than the old legend can give, without having to spend vast amounts of money on it. I'v always got at least one old XK engine lying about though... as the AJ6/AJ16 can't compare to triple SU's, chrome cam covers and the like.
Regards,
Rich
richw_82 said:
The AJ6 was tested as early as in the Series 2 XJ6. There isn't that much needed to do to put one in an XJ, and so far to put an AJ16S in has only cost me two 8mm holes to mount the power steering reservoir. There are no major modifications - it bolts in nicely.
I like the XK engine, its got guts, and the sound of it when pushed hard is glorious. But - I need more performance and better fuel economy than the old legend can give, without having to spend vast amounts of money on it. I'v always got at least one old XK engine lying about though... as the AJ6/AJ16 can't compare to triple SU's, chrome cam covers and the like.
Regards,
Rich
Sounds good - any photos?I like the XK engine, its got guts, and the sound of it when pushed hard is glorious. But - I need more performance and better fuel economy than the old legend can give, without having to spend vast amounts of money on it. I'v always got at least one old XK engine lying about though... as the AJ6/AJ16 can't compare to triple SU's, chrome cam covers and the like.
Regards,
Rich
Are you using a manual gearbox or the 3 speed automatic? The problem with the old XJ6 was the combination of 3 speed and subsequent low gearing with an engine that didn't take kindly to high rpm. And somehow, a manual box seems out of place in an XJ.
The AJ16 is the later 4 litre is it not? I've not driven one of those, but I thought the 3.2 in the X300 was a very nice engine.
Touring442 said:
Sounds good - any photos?
Are you using a manual gearbox or the 3 speed automatic? The problem with the old XJ6 was the combination of 3 speed and subsequent low gearing with an engine that didn't take kindly to high rpm. And somehow, a manual box seems out of place in an XJ.
The AJ16 is the later 4 litre is it not? I've not driven one of those, but I thought the 3.2 in the X300 was a very nice engine.
Yes, the AJ16 is a development of the 4.0 AJ6. It uses independent coilAre you using a manual gearbox or the 3 speed automatic? The problem with the old XJ6 was the combination of 3 speed and subsequent low gearing with an engine that didn't take kindly to high rpm. And somehow, a manual box seems out of place in an XJ.
The AJ16 is the later 4 litre is it not? I've not driven one of those, but I thought the 3.2 in the X300 was a very nice engine.
on plug ignition and has a few other refinements. It gives a slightly
higher output as I recall.
These engines use a 4 speed autobox not the old GM400 3speed.
Ours also had the " sport " switch option on it.
Touring442 said:
You misunderstand.
Yes, of course the C and D Type engines were specially prepared. To prove that point, drive yours at 5-6000 rpm constantly and see how long it lasts before it goes bang. I don't think it will q-u-i-t-e make 24 hours.
Why would I want to drive an XJ6 at 5-6000 rpm constantly ? The beauty of the XK engine is that with that long stroke you don't need to rev it.Yes, of course the C and D Type engines were specially prepared. To prove that point, drive yours at 5-6000 rpm constantly and see how long it lasts before it goes bang. I don't think it will q-u-i-t-e make 24 hours.
I'm not disputing the later engines are an improvement only that the XK engine is perfectly reliable in normal use.
I've owned dozens of Jags modern and classic including several XJ6's and I've never felt the urge to change the engine.
Very few old XJ6's are used now for stellar mileages and I just think the trouble of changing the engine wouldn't be a worthwhile option for most owners. Especially if they have to pay someone to do it.
Let's agree to disagree
Touring442 said:
Sounds good - any photos?
Are you using a manual gearbox or the 3 speed automatic? The problem with the old XJ6 was the combination of 3 speed and subsequent low gearing with an engine that didn't take kindly to high rpm. And somehow, a manual box seems out of place in an XJ.
The AJ16 is the later 4 litre is it not? I've not driven one of those, but I thought the 3.2 in the X300 was a very nice engine.
AJ16 4 litre supercharged is what I'm using, but the AJ16 is pretty much the same without the strengthened internals. The AJ16 block has a lot of casting similarities with the AJ6 so it fits easy as that engine went in the XJS, which is essentially a shortened XJ6 platform. As I said earlier it is quite simply bolt in.Are you using a manual gearbox or the 3 speed automatic? The problem with the old XJ6 was the combination of 3 speed and subsequent low gearing with an engine that didn't take kindly to high rpm. And somehow, a manual box seems out of place in an XJ.
The AJ16 is the later 4 litre is it not? I've not driven one of those, but I thought the 3.2 in the X300 was a very nice engine.
I've had a 4 litre AJ6 in an XJ40, and was always annoyed by how capable the car was, despite looking as it did. Wanting to put one of those engines into my Series 1 kind of sparked it off... research showed that it puts out slightly more horsepower than a V12 for significantly less weight, and with better fuel consumption.
I'm using a Getrag 5 speed manual from an XJS, and I have to disagree slightly with you over whether it suits the XJ6. It depends on the car! My series 3 is very heavy, the steering is heavier, and it feels less hurried than the Series 1. The Series 1 is a short wheelbase manual originally, and it is very much a drivers car. The 4 speed and overdrive suited it well, so the 5 speed should be a good substitute.
I am using as many off the shelf Jaguar components as I can, and making as few extra holes as possible. There's also a little pride involved at knowing it will all still be 100% Jaguar.
My pet hates in the Series 3 are sitting at 4000rpm to do 80mph, and the archaic 3 speed being unable to decide which gear it wants at 30mph; so that may get a different gearbox (probably the ZF 4HP22, with a 3.54 back axle) in the future. However, it will keep an XK engine and get the triple SU's that I've had stashed away on it too.
Just about to go out, so can't post many pics (I've not been taking that many either) but here it was about a month ago when the engine was going in:
Regards,
Rich
mph said:
Why would I want to drive an XJ6 at 5-6000 rpm constantly ? The beauty of the XK engine is that with that long stroke you don't need to rev it.
I'm not disputing the later engines are an improvement only that the XK engine is perfectly reliable in normal use.
I've owned dozens of Jags modern and classic including several XJ6's and I've never felt the urge to change the engine.
Very few old XJ6's are used now for stellar mileages and I just think the trouble of changing the engine wouldn't be a worthwhile option for most owners. Especially if they have to pay someone to do it.
Let's agree to disagree
As posted... 80 mph is 4000rpm, which is way past relaxed. I do 12,000 miles a year in my XJ6's (Series 1 and now the Series 3) and I still think the XJ6 line was killed early, by not getting the AJ6.I'm not disputing the later engines are an improvement only that the XK engine is perfectly reliable in normal use.
I've owned dozens of Jags modern and classic including several XJ6's and I've never felt the urge to change the engine.
Very few old XJ6's are used now for stellar mileages and I just think the trouble of changing the engine wouldn't be a worthwhile option for most owners. Especially if they have to pay someone to do it.
Let's agree to disagree
Also living in the Peak District, the low revving tendancies and 3 speed auto can be downright embarrassing sometimes on large hills.
Worthwhile? Depends on your point of view. It is to me for the benefits gained, and by the fact I'm doing it myself. I doubt it would be for others - but the XK is still good enough to hold its own in most situations.
Regards,
Rich
Edited by richw_82 on Friday 27th May 16:57
richw_82 said:
As posted... 80 mph is 4000rpm, which is way past relaxed. I do 12,000 miles a year in my XJ6's (Series 1 and now the Series 3) and I still think the XJ6 line was killed early, by not getting the AJ6.
Also living in the Peak District, the low revving tendancies and 3 speed auto can be downright embarrassing sometimes on large hills.
Worthwhile? Depends on your point of view. It is to me for the benefits gained, and by the fact I'm doing it myself. I doubt it would be for others - but the XK is still good enough to hold its own in most situations.
Regards,
Rich
Yes the old three speed box is the weakest link. My S3 has a five speed manual fitted which makes a massive difference.Also living in the Peak District, the low revving tendancies and 3 speed auto can be downright embarrassing sometimes on large hills.
Worthwhile? Depends on your point of view. It is to me for the benefits gained, and by the fact I'm doing it myself. I doubt it would be for others - but the XK is still good enough to hold its own in most situations.
Regards,
Rich
Edited by richw_82 on Friday 27th May 16:57
Good luck with the conversion and take more pictures !
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