I had a few questions as far as improving the power of the factory engine.

Does anyone offer a stroker kit for the 4.0?
Are headers available?
Has anyone had their cams reground or computer reprogrammed?

I'm very familiar with the GM LSX engine, but not so much with Jaguar. I'll probably do an LS conversion, but figured I'd look into what can be done to the Jag motor.

Thanks.

 

Talk to these guys: Welcome to Buckhead Imports

Or trade-in for an XKR.

 

You need a LSx conversion.

The '96-'03 models of the XK's and XJ's have become so financial attractive that lots of new folks are dreaming about a new custom ride.

We need a separate forum for conversions post to get them off here. I post on several vehicle forums and this can get completely out of hand from dreamers. Let them post and enjoy.

That is what makes this forum different . . . and successful.

 

I believe that the 4.4L Range Rover engine had the same outer dimensions, though I'm not sure. It might be easier to make that swap than to stroke a 4.0 or swap an LS.

I understand the appeal of the LS swap for some folks, but making a Jag sound like a Chevy truck isn't my cup of tea.

 

There has been a bunch of info on a posting the last week on replacing the engines with late model GM engines.

I suggest you look for it. Someone is making a Jaguar/Chevy conversion kit, but it's not very clear what you get for your money. It almost looks like you should look for a good Camaro junk to get a port injected motor and wiring harness, etc. out of . A junk would save time and expenses--and you can sell the rest of the parts on Ebay.

Not much speed equipment is available on the 4.0 A26 or A27 Jag engines. The 17 or so electronic modules (CAN/BUS) and present throttle body are just too hard to deal with on a stock motor--much less if different cams and other modifications were done.

 

I stroked my 4.0 to a 4.2, very easy, I had a nikasil engine and 3 damaged pistons, but I managed to get hold of a very low mileage crank, rods, shells and pistons from a 4.2 and fitted the lot, worked a treat.

I have also done 4.4 setups using a range rover bottom end, they get the extra capacity from larger pistons but the crank is the same as a 4.2

All these parts are available from Jaguar at horrendous money, if you want more capacity it is cheaper to get a 4.2 engine and swap all the ancillaries from your 4.0

 

I forgot

Headers are a waste of time, yes you can get them (stupid money) but they are just copies of the cast item done in stainless, pointless imo, you need to achieve equal pipe lengths, there is simply no room.

You can get up to 4.7 using an Aston AMV8 and the headers are to die for but again no room in the XK

 

Lol, I think I'll stroke mine to 5.0 after lunch then

 

Now that is wishful thinking

4.7 is the biggest you can go, Aston only achieved this using a flat plane crank and taking the bores out to 88mm (I think), that would change the sound from a V8 to something a bit different

 

"The cylinder bore and stroke has been increased from 89mm to 91mm and 86mm to 91mm respectively, giving a total displacement of 4735cc.

The increase in cylinder bore is facilitated by a move to cylinder liners that are pressed into the pre-machined aluminium alloy block, allowing a thinner liner than was possible with the cast-in design of the 4.3 litre engine. "

The newer engines really have a flat plane crank? That's cool. So they sound like the Ferrari V8s?

 

Not sure where you are coming from, the difference in sound from a truck to a car is the muffler system, the LSx engines are exactly the same for cars and trucks, with slight differences in cam specs and early LS1 truck engine heads were iron, but these make little difference in sound.

 

The newer 5.0ltr is nothing like the old AJ engine, different heads, different block and different super charger........ Aston Martin used the flat plane

 

That's kind of my point... the LS engine is so common that the exhaust note lacks distinction, whereas what it'd be replacing is something very uncommon.

 

It might be possible to stroke the engine to 4.5 ltr (at least this is what Arden has done), not sure if you can get away with a relatively cheap regrind though. Boring out the 4.0 and 4.2 engines isn’t worth it, as the cylinder walls are too thin.

But I know that the last 4.2 versions from the range rover engine has thicker walls, and iirc count iblis mentioned that the US spec 3.9 ltr engines (2003+ engines form the Thunderbird/Lincoln ls, which can be had very cheap) where able to be bored out more and I think a square 4.8 should be possible with the ductile sleeves from Darton for instance (was on my list to do if I win the lottery).


The throttle body can be bored out.

Cams can be regrinded, I used Catcams in Belgium, and it cost me about 480 euros (some work is needed to fit) , and gains are about 5%.

As already said by others, it will be cheaper to trade in for a XKR, and then you still have enough room for improvement.