Commonly done, on race cars in Production classes, but destroys the carb for street use.
Low-end driveability goes right into the porcelain convenience!
Has anybody forced air into the XK? I asked around at AJ engineering, and their response was why would you do that. The engine is old as dirt. (paraphrasing). I’ve seen it done on the V12’s but not the XK.
Just curious; I have a turbo set up kicking around, and thought that might be an option for my track day car (when I get to that point). I don’t however have the injectors, throttle body and airflow sensors (other than stock); not to mention the ECU. Just curious really.
In Des’s book he states (If I remember correctly) that most of the mods in the book are performance increases in the high rev range. But 4.2 that’s a lot of mass to be tossing up and down at high revs. Of course no practical experience.
Well off to the breakers yard to get bits off an Series III XJ that I stumbled upon.
There have been torbocharging/supercharging efforts done to XKs: the big issue is that oc little room for packagong.
For street, I still think your best bet is a lightly-breathed on 4.2, with the later SIII, Wide blade rods, a well-flowed and mildly cammed head, and a close ratio 5-speed.
Were I ever to own an E Type again—and I won’t—that is what I’d do with it.
For a track car, Id get an Ariel Atom! 6 times the performance of an E Type, at a fraction of the cost of a modded E monster.
I would agree on the Ariel Atom. A bit out of my price range. The more I hang out on this forum, I am beginning to think I’m the poor chap on the block. 
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LOL…ariel atom? A more impractical vehicle is hard to imagine. Add to that the atom is skittish and a death trap for unskilled drivers…I cannot imagine anyone pining to get one of those.
You did see where I specifically stated it as a “track car,” no?
I assume you speak as someone who’s driven one? I did, on a track, a few years back, and it was ANYTHING but skittish and unsafe.
“Add to that the atom is skittish and a death trap for unskilled drivers…”
Frankly, in the hands of most drivers, an E Type, or any other reasonably high-performance car can be dangerous, for track use.
I never suggested it as a grocery getter, but, in the summer? I’d be tempted to go get a flagon of milk in it, via Turkey Creek canyon…
Exactly!! Living on the edge! Haha
yay, I found my copy of his book
he always mentions whether it is road or track
In addition to what I added before, for a road car;
he does also advise that the head should “have 10-12hrs with a competent machinist” to increase & smooth flow…for a road going car…(30-35 hrs mods for a track car, will use lots of fuel, etc)
valve & seats angle cut
ignition timing be (carefully) advanced
all components properly balanced
I know of a S2 XJ6 with (at least) the additional following mods, used on road & track
triple SU, D-type profile cams, electric fans & water pump, coil over plug ignition using GM parts and a custom PC map (no dizzy)
also a low ratio diff and overdrive gearbox, I think the diff is a 4.10
Wow!
All of the above is do able (for me) except the last bit. distributor less ignition. How in the hell, did they do that? unless it’s all done with a ECU? being a software engineer by education and trade, I guess it could be done electronically without any form of crank trigger or mechanical triggering. but I would think there’s gotta be some form of mechanical check and balance. I suppose a magnet could be mounted on the cam gears, and a pick up sensor (simple normally open switch) as a TDC check. but if they went to this kinda trouble why not do FI too.
Oh, and the 4.10 gear ratio, where did they find the ring and pinon to change the gear ratio? that is one of my biggest complaints about the later Jags is the insanely high gear ratio. North American cars only produce 170bhp (XK6) and the V12 is just shy of 300bhp, why wouldn’t they change the ratio so getting to legal speed limit would happen a bit sooner.
Then I think about it, and this was the 70’s and 80’s. These cars were at the top of their game. when the XJ12 hit the streets it was the fastest production Saloon in the world. When the XJS popped up it was also the fastest production GT car in the world. I won’t get started on the XK120, XK140, or the XK150’s. As I write this thread, I think. Of course! This IS Jaguar. Sleek, Stylish, and FAST!. Not quick; FAST!
Thank you Sir William Lyons, I am forever grateful!
cheers!
Mark
The 2.8 XJ6 had a 4.09 standard. These are also fitted to older Jags, up to 4.55
I believe some machining is required to fit these gears
I also own older Jeep Cherokee, and the standard “fix” for more acceleration is to go from standard 3.54 to 4.10, (but they already have an OD trans)
The ignition is done via a “Wolf 3D” ( aftermarket programable system).
I believe it also handles FI, if fitted, dont know why the guy hasnt done that,
but I think the coil over is fairly simple, a crank sensor is fitted,
it may be like Rays EDIS system on the E-type list
Its been on a rolling dyno, and I cannot recall the figures, but it was from memory it was estimated close to 300 engine HP (could be wrong about that)
what part of the world are you in Tony? Because here in the States, I don’t think we ever (or atleast I haven’t) seen any 2.8 XK Mostly the 4.2 XK. I will look into wolf 3D
I like the thought of a better gear ratio offerings 4.09 fitted with a manual gear box I’m assuming; and the Salisbury rear diff. though I have no practical experience with the older IRS Diff, I understand the gearing can be changed if the ring and pinion can be found. Most of my cars are of the 80’s and 90’s so my IRS experience is with the Dana Diff. which I came to learn the hardware the ratios can’t be changed. I couldn’t believe it. A Dana that can’t be changed? Seriously? there’s a bazillion of Danas out there and Jaguars’ can’t be changed. Well that just isn’t right.
sorry, side tracked.
Thanx for the info,
mark
Brian Hartman, a prolific author of engine management, forced induction, and fuel injection books, usually features his triple-turbo, fuel injected E-type (he also refers to it as an XKE frequently) in those books. Because of this it might be the best documented example of such an installation. He’s had it for a long time, but updated over that period with newer technologies, as you can tell from his older books to the newer ones.
Those chapters will give you some idea of what it takes to properly turbocharge an XK engine, especially in the E-type chassis. It’s not trivial to be sure.
Dave
While fitting EDIS isn’t exactly a Saturday afternoon project, neither does it involve a Phd in rocket science. @Ray_Livingston produced a kit at one point, and if you search the forum here for “EDIS” you’ll find lots of information about that. If I’m not mistaken you can fit EDIS with only minimally intrusive mechanical changes (a trigger wheel on the front of the crank, some bracketry, and a place to mount the additional components).
Going to FI would be a lot more work, although Burlen announced a “Steallth” FI system at the end of last year. Other than the announcement they’ve been rather quiet about it though. Given that their Stromberg to SU upgrade kit is north of 3500GBP, I suspect that the FI retrofit wouldn’t be particularly cheap, but if you already have a triple manifold and source 3 donor HD8 bodies and some higher pressure fuel feed bits and bobbles, then all you’d need is a small mill, some advanced fabrication skills and a great deal of commitment and spare time.
The bottom line for me is that the stock setup is fine for road use, if you want to get into historic racing then you’ll probably run into problems with their allowed modifications. I am not an originality purist by any means, but there are some things which a gentleman just doesn’t do. Taking a refined saloon like the XJ and turning into a chirp shifting land rocket which needs wheely bars and a parachute isn’t cricket (It’s more like cage wrestling). If you want to do burnouts then consider a 442 as a second car.
You are right, it’s not a trivial fitting. pushing air into mechanical based (ie no electronic governesses) engine isn’t trivial. There’s a ton of adjustments to be made, temp, timing, fuel ratios, plug heat range. granted these are necessary weather or not there is an electronic governess, but I think without the job is much more fiddly. And there’s so much that can change due to climate, time of the year, and elevation. this is especially critical with timing, get that wrong, pre-detonate, and the end result can be catastrophic. I’m not sure that is route I’m gonna take with a carbureted XK or an XK at all for that matter. I’ve got a 4.0 Jaguar V8 from a 2000 XJR sitting in the garage. That may find a home in a project XJ.
Just dreaming now.
thanx
mark
It depends… Dana 44 and Jag Salisbury IRS have the same design roots, and Dana R&P can be fitted (with qualifications)
this page describes the detail
I have the idea that the tri-carb/manifold setup allows for similar/equal raw power as FI setup, and the main advantages of FI would mainly be in areas like fuel consumption, pollution, smooth idle & warmup ?
(stand to be corrected though)
If the tri-carb setup is obtained from a cheap wreck MKX/420G, much less costly too, although they are getting hard to find
I dont think the XJ6 is very suitable as a fast road car these days, even an XJ12 is too heavy and slow.
My Mrs 2.0L Mazda would romp all over our cars
You’re right. The easy way would be to fit an injected head (post 1978?) and possibly just run some more modern electronics… but most people starting down this road eventually suffer from scope creep… (myself included). I’ve seen a few cars (of various marques) which have been upgraded to the point of being unpleasant to drive, including a few which cost more to put back to “mostly stock” than the original upgrades cost in the first place.
It’s all too easy to think “I’ll fit a new wiring harness while the shell is bare, adding some fuses and relays.” and not long after that you’re contemplating a CAN bus installation on your Mark VIIM.
Andrew thank you for your input, I concur 100% about a refined saloon and turning into a tire shredding sled. this XJ is anything but refine. It’s what I call a FrankenJag. It’s comprised of all sorts of Jaguar bits from different series and years, it’s been a nightmire to get stuff to work properly.
The car is a mess, the panel gaps are atrocious, I’m constantly chasing the rust around with my TIG welder. the seats may as well be fitted with toilet seats because that’s the way it feels when I drive it. the foam in the center of the seats has turned to dust, the headrests look like 90 year old D cup breasts fitted on top of the seat backs - completely deflated.
It’s my daily clapped out driver. This car is the poster car for why you shouldn’t by a Jaguar. But I love to drive the car.
Granted the car was essentially free and the sole reason I acquired this XJ is, well, I saved this one from the crusher (This car and I have history).
I’ve got close to 3 grand US dollars in parts alone it as it stands, suspension rebuild, new braking system (drilled and slotted rotors 
, new ignition, new fuel pumps, new pair of Stromberg’s. It’s getting a new rack tomorrow performance mod upgraded from the Series I rack to the series III to improve the driveability.
If I do anything with this car other than do my best to return it to stock, some internal engine work. fit a manual gearbox and a triple Stromberg carb (the car came with two already fitted). weld up a new intake and exhaust (can’t afford to buy one) make everything fitted so looks like that’s the way it came; and drive it.
The only reason why I’m keeping the car is my daughter loves it, and it’s a SWB Series II. which I understand there aren’t very many left. They’ve pretty much all rusted away. I get that!
Anyway, Andrew I agree with you. what ever I end up doing to this car it will be civilized.
cheers!
Thanx Tony,
Good info!
Oh, did I mention that this XK has the FI head on it with the Stromberg’s? I also have a complete FI intake and ECU. Hell I’ve got a complete XK Series III ('86) engine already fitted with the FI in garage, all I’d have to do is wire it in and change out the fuel tanks, oh, and plumb for the fuel return. emissions aren’t a concern where I live. the fuel economy is a plus my series III gets about 18mpg around town and 22 on the highway. respectable for a 30 year old car.
Raw power and a Series III XJ6 (US Spec) are two words I wouldn’t put together. reliable? yes absolutely! efficient? yes!, Raw power? not so much.