Mk 1 2.4ltr engine

Does anyone have tuning mods and relative output figures for this engine and can it be bored out to 3.0 ltrs. Also has anyone tried changing the con rod length ratios to get better performance. Was this the engine used in the 3.0 ltr light weight EType. This engine s/b good for at least 200 bhp, but I can’t find anything that comes close?
Thanks HG


It would be thousands of dollars, pounds or Euro cheaper to just start with a 3.4L or 3.8L, or 4.2L. The 2.4 has a much shorter deck height compared to all other XK varients, 8.85" vs 11.5". Why spend thousands for longer rods and custom pistons just to wind up with something with a litre less displacement than a 3.4, much less a 3.8L or 4.2L? The 4.2L was built in such great numbers they are cheap and easy to find. A stock 4.2 would kick sand in the face of a heavily modified 2.4L.

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You will not easily get the 2.4 out to 3 litres. If you really want that, start with an XJ6 series 1 2.8 litre block and crank. Exactly the same external dimensions.

Thank you John. So does that mean that the block is still 3" shorter than the 3.4/3.8/4.2 and if so the problem is I don’t think they were exported over to Noth America. My objective is to fit it into an MGB without having to put a bulge in the hood. I know there are a lot of other engines that would work, but I wanted to keep it in the realms of a classic resto mod.

I gave an answer this morning on the Ssloons forum to a french chap ssking about 240 heads. Go to for Jaguar’s own 2.4L tuning advice.

The 2.4 Mark 1 was exported here, but not in great numbers, especially after the 3.4 Mark 1 became available. It is indeed shorter height than all the other XK engines. If you find one you won’t have to pay a lot for it.
It had Solex downdraft carbs, again not in great demand, but if you find one you will probably want to put SUs and manifold from a 3.4 on it.
Try Jaguar Heaven in CA, Coventry West in GA, and there is another all-Jag scrap yard in TX. Put a wanted ad on this web site.

Is it correct the 2.8 block dimensions are the same as the 2.4 ?

I have an XJ one from an XJ6 that is surplus to my requirements, it turns over.
believe it has the same or compatible head to the later 4.2

It is complete with HD8 carbs, and I believe a BW35 trans

I think someone previously advised me it would be a reasonable upgrade for a 2.4 ?

Yes the 2.8 is a short block same dimensions as the 2.4. The engine was 83x86mm for 2792cc.
The engine developed as a 3 litre for racing was alloy and I believe was also the same short block size, but 85x88mm for 2996cc
It would be a great project to get a 2.8 litre block, sleeve/bore to 86mm for 2997cc. It should rev very well indeed.

What country are you located in? That will have an impact what is available to you. The 2.8L XJ6 was never imported to North America.

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That’s actually a good reason to choose a 2.4. We’ve discussed this sort of thing before with a guy who bought an incomplete D-Type kit car body with a home built chassis. The chassis design didn’t leave enough room for a Jaguar engine to clear the bonnet closing. He was going down the path to a complete dry sump system, which would have cost thousands, just to gain a couple of inches. 2.4 was just the ticket for him.

Where are you located and how much do you want for the engine/trans. Thanks Hedley

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I am in Canada so sorry I think it would be expensive to ship.

Cool as it would look, the 2.4 Jag is not much lighter that a 3.4-3.8, while making much less power and torque. Can’t imagine the intake would fit the engine bay. There’s a reason no speed parts are made for that thing (owned one in a MKII, btw). The MCG went to front torsion bars to make room for that heavy 3.0L lump they put in there.

There are so many better and affordable engine choices out there. A crossflow head for the MGB with single sidedraft DCOE Weber would be cool. A twincam Toyota or Ford Zetec are both relatively plentiful and cheap and could be made to look fairly retro. I’ve seen a '70’s BMW 2.0L with later 5 speed done. That was a sweet installation, and the engine is designed to be canted over a bit, helping with bonnet clearance.