3.5 Liter XK engine?

I have an XK engine that is embossed with 3.5 liter. Is this real ?

No, that’s not correct. It should say “3 1/2 LITRE” not “3.5 Liter” and the marking is not embossed, it is part of the original mold and it stands proud of the block on 3.4 Litre engines.


Example of my XK140 3 1/2 Litre engine

1 Like

You are correct. That is what it looks like, so it is real. Thank you.

It’s optimistically rounded out for marketing purposes. If that bothers you, you probably don’t want to know what the actual HP and torque figures are as compared to the claimed numbers.

1 Like

Nothing to do with optimism, only that the British were used to working with fractions.
Are you aware that on all 4-cyl MKIV’s and SS Jaguars it says 1 1/2 Litre?
In reality they are 1.8 litres. It’s more like one and a half-ish and three-and a half-ish.

Also all 2 1/2 Litre Jaguars and SS Jaguars are more like 2.7 or 2.8 litres.



Not so sure about marketing purposes, but more about euphony…

  • 1200 Datsun? Really a 1171.
  • 1600 Datsun? Really 1597.
    The list goes on…:crazy_face:
1 Like

… how about the 6000 SUX ? - I believe it ran a 6600 (in the larger form…) :wink:

1 Like

3.5 LITRE on early blocks and 3-1/2 LITRE on later, mid 60’s blocks?

I wonder why Jaguar, even as far back as the SS range, were using a metric measurement for their engine capacity?

In the early days, they used RAC HP rating (ie SS1 16 HP or 20HP) But the British not only Jaguar always (?) seemed to measure engine capacity in metric, unlike Americans who used Cubic Inch. As to why…

Cos their engines were so bloody big that Cc’s would sound daft :joy:

I thought (perhaps wrongly) the convention was the number was rounded to the nearest decimal point

As an example I was once conversationally chided (by a dickhead) when asked size my engine was in Litres, as I had described it as a 345

I said it was a 5.7, which is the same description given to 350 Chevy and Ford V8s in Australia.

It is 5654 cc, which is closer to 5.7, than 5.6

(without checking) I think the XK engine is 3442 cc, so if my convention was right, it would be a 3.4

My 4.2 is bored .030" , so that technical makes it a 4.3L

I could pinch the “3” out of a 5.3L chrome for my boot lid if I wanted to pimp my ride :laughing: