manual V8 swap into XK8 ?
 

I don't (yet) own an XK8 but as an armchair expert :icon_couch: (I have stood outside one with owner revving it for me, and sat in a couple at auctions) I have the following comments re this smart coupe:

1. Its about the most beautiful modern out there, but .....
2. As standard, the V8 sounded like a Ford Mondeo from outside. Inside it must be even more muted and rather bland in sound. Nothing compared to a TR8 and so tame compared to any TVR V8. Is it just the exhaust and mild cams?
3. I'd like a manual. The only serious conversion I heard of never became commercial as it was going to cost a good £7k+ between fitting the gearbox and tweaking the ECU to deal with sensor issues.
4. Luxury cars like this one have too many sensors of dubious quality, and at this sort of age they seem to be causing false alarms, causing the car to go into limp home mode when it doesn't even have a real fault. Range Rovers of this vintage are even worse, and Mercedes similar (I tried both!).

So I have a ghastly armchair solution seeking comment from the wise ... does it make sense to buy one and when it gets the electrickery gremlins take out the engine & box, remove the airbags and fit another V8 & box .... perhaps a Rover unit, perhaps a TVR tweaked, perhaps even a 1960's Jag/Daimler 2500 V8?

I have read that MOT emissions tests should be taken from the provably oldest of either engine or body, so emissions won't be a major issue. My aim is to achieve a great body with a manual V8 and reliable, simpler electrics. I don't really care that much about safety airbags and even ABS I see as 'nice to have' rather than a must. I don't seek ultimate speed/accelaration but do want manual with a V8 burble that can be heard by the driver.

Any thoughts?

I wasn't absolutely sure about this and so I looked it up in the current UK MoT Inspection Manual.

Section 7 relates to emissions and SubSection 3 covers replacement engines:

Attachment 76896
(click on the image to enlarge it)


The paragraph boxed in blue confirms what you have read about fitting an earlier engine.

Note that the onus is on the vehicle presenter to prove engine age. The only way to prove this is by providing a copy of the V5 Registration Document for the donor vehicle which will show the engine number and date of first registration.

Graham

Thanks Graham. A curious rule isn't it ? Fair enough that if you mod your modern engine it must still meet emissions for its age. Remarkable though that in principle I could transplant a 1976 3.5 Range Rover V8 and manual box into a 1996 XK8 but only need to comply with 1976 emissions rules.

Aside from the rights & wrongs of such action in terms of the environment (& that could be a circuitous argument) I am very attracted to the idea of running an XK8 manual which has had the electrickery completely disconnected from the gearbox, with an ECU simply required to run a fairly basic efi sytem .... or dump the efi and ecu for even greater simplicity. The engine used in teh Daimler Dart SP250 in particular seems to be a dream of an engine, but perhaps that is a bit rose tinted!

If this is all a reasonably sensible option I may consider it. If not, as I don't particularly want a convertible, I am toying with Porsche 928. The Lotus Eclat will take a V8 but as it has a light engine as standard this may not be so wise. TVR have some appeal but in my sort of budget there is often extreme chassis rot. TR7/8, well not too bad but they do have such a rust problem, though are fairly cheap to maintain. The XK8 is so beautiful (outside). I am not convinced about some of the interior bling but could doubtless be persuaded!

Anything is possible if your pockets are deep enough.

I think the footprint for re-using a car and engine is probably still better than a new car. Running the base XK8 with 290hp to a Rover V8 is a big drop in hp as well.

Have you considered a Jenson Interceptor? Also one of the best looking cars..

Indeed, I too feel the environmental impact of re-use is less than scrap and build new ... even with a greener engine.

The Jensen with a 7 litre engine would make me cough in all regards.

My thoughts re perhaps dumbing down the XK8 to a smaller V8 (manual) with less electrics is to not only reduce petrol and engine/box maintenance costs, but also to increase reliability by eliminating the need for some sensors and eliminating faulty sensors (as distinct from genuine faults) incorrectly putting the car into limp home mode.

I am a bit of s troppy so and so at times, I can understand a manufacturer of a powerful car wanting to force safety considerations onto its owner where there is a genuine fault in say the ABS ... but cynically I feel that this has more to do with reducing the risk of the manufacturer being sued for negligence by wealthy customers after an accident, than it has to do with a real need. If my ABS warning light comes on I would like to be the one to choose whether to ignore it completely, put myself into 'limp-home' mode or simply drive with caution till it could be investigated ..... I resent a car telling me what to do, especially where it is a gremlin rather than a genuine fault!

Have you considered a Chevy LS1 V8 swap with a manual conversion? They can be made to work with the electrics of the Jag and provide endless possibilities for more powahhhh!.

I suspect the arguments of a car enthusiast MP could have had a hand in this retro fit emissions exception.

I'm all for taking engines out of Daimler SP250's. The sooner that ugly body design is obliterated the better. :icon_lol:

Graham

I am not brave ... I am rather scared of XK8 electrickery so I think your suggeston would be XLNT for someone who wants a manual XK8 and is prepared to put up with the vagaries of the electrickery, but (armchair expert that I am) I don't feel I want to do that really.

I did read a terrific article or two on a company who spent huge efforts in developing an ECU that would allow a manual box to trick other ECU's (I think) into believing the auto was still there & stuff I don't understand. They fitted a manual box and the results were said to be great, with a diff or crown wheel change needed but not done .... then it died off as uncommercial with conversion costs being too high at £7k+

maybe I'm in cuckoo land:icon_lolsign:

drivetrain from an Aston?

Some interesting thoughts. You are correct about the muted sound, but I think this is because Jaguar tend to aim towards luxury and comfort, which TVR did not. However, you can make changes to the exhaust to address this, take a look at some of the threads on here.

Don't be too concerned at all the sensors, I am not sure that they are any worse than any other modern car. I have had my XK8 for three years now and the only mechanical problem I have had is a failed fuel pump. The worst thing is not using the car for any period of time.

I believe that XKRacer did put a manual gearbox in an XK, but not sure whether he would advise it - perhaps he will see this thread.

Here in the UK you have to check carefully for rust, particularly at the rear of the sills and the front floorpans. This is a problem I have to address with mine. Again this is a matter which has been addressed elsewhere on the forum by XKRacer.

My advice is that if you like the car, get one and live with it for a while and see how you get on with it in standard form, then decide if you wish to make changes.

Good luck with your search.

Jaguar Specialties makes kits for engine conversions and is working on a manual trans kit as well.

Jaguar Specialties

If I recall what Mr Racer said about pairing a manual with the Jag motor, it is not for the feint of heart or those with shallow pockets.

I would go down this road.

LS1 5.7 or 6.0 V8 & Tremec 6-speed manual from a wrecked Vauxhaul Monaro / VXR8, otherwise known as a Holden Commodore.

Easy enough to get 400hp out of one of these engines. Maybe not so easy to source in the UK, but cheap as chips in the US or down here.

Thanks renaultvation for the heads up........how handy is our Mr English with the spanners?

At the end of the day still doing what you have asked about will cost a lot of money, even if you did chuck in a rover V8 you have the knock on effect of clocks/gauges and security issues.......

You will be still looking at thousands, it costs serious money to tune a rover v8 even up to a standard XK8, sure you could pick one up, I have a 3.9 at this moment in the store across the yard, but to rebuild it and get it any where near 290 brake will cost £4k, then the conversion cost........ Too much

You could just buy the engine as is for about £400 on ebay but you will need an LT77 gearbox that will be another £500 if you can find one, pedal box will be a few hundred unless you adapt one from an an XJS like I did but even those are now in the realms of rocking horse poo! Gauges will be £700 unless you ditch keeping the original look, then you can do this very much cheaper...... We just probably spent £2k before we have even picked up a tool..

Stick a SBC in it, only needs 2 wires to make it run, cheap to tune, cheapish to obtain, even in crate form, loads of gearbox options.........

But even after all that you will still be looking at a lot of money...... Going back to my original question of how handy are you with the spanners? Also a machine shop will be very handy because if you can do all that yourself you would save a mahoosive amount of money, but, it will still cost IMO in the region of £5k to do what you want/ask for....

Damn expensive this car modding, conversion malarkey!

Right, there are some really helpful answers above and thankyou.

In summary, its a daft idea isn't it?

Yes, I'm handy enough with the spanners but work 6 days a week running my business and also run 2 classic cars, 1 classic motorbike and have another classic on blocks 'waiting'. Together with a period house needing work, couple of acres & 7 grandkids ..... so if I was to take this on myself I'd be for the SWMBO highjump and if I paid someone to put my theory into practice it would not be cost effective.

Ah well, I'll settle back on the couch with a tinny tonight and drop this particular hot potato, until perhaps retirement in 30 or 40 years by which time I'll be dribbling in my zimmer frame.

Now if anyone happens to have an XK8 running a TVR V8 manual that they are having trouble selling due to silly warning lights coming on, just give me a call as I might be able to take it off your hands .... not much market for that kind of bodged up motor you know.