Jaguar sump capacity

[droopsnoot]

I know we have some Jaguar aficionados on here, so I wondered if anyone could help on this.

A mate has recently bought an XK140 project car in "to be rebuilt" condition, and it's come with an XK engine that has "3 1/2 litre" cast into the side of it. Is that normal for a 3.4 engine? I've had a look around and it seems that the engine number starting with "N" means that it's from a Mk VII or Mk VIII car originally, which would make it 3442cc.

It has no dipstick, and while it's easy to suggest putting in the correct amount of oil and then marking whatever he fabricates (apparently dipsticks aren't easy to get), the question is what the capacity should be. He's looked around and found various different capacities, many around the 12 pint mark but one at 19 pints, which presumably is based on different sump sizes. This is a photo of the sump (which to me looks as if the bottom section has been welded in place) - can anyone suggest what the oil capacity should be? I don't know Jaguars, but I imagine that just because the engine is from a Mk VII or VIII, that doesn't mean the sump is the original one.

[TarquinMX5]

It would seem that 3 1/2 litre was stamped on early 3.4 XK blocks

https://www.jaguarforums.com/forum/mki-mkii-s-type...

No idea re sump capacity, especially as it appears likely that it may not be the original engine.

[finlo]

Surprising they used litres on an old Jag engine, though I can't recall any UK engines referred to in cubic inches.

[a8hex]

The 3.4 XK engines did have 3 1/2 Litre very prominently cask on the side of the block.
As you say an N engine is from a Mark VII or Mark VIII

https://www.jag-lovers.org/xk-lovers/library/engin...

Originally an XK140 would have had a Gxxxx series engine.

I'll have a look tomorrow in the service manual for the XK140 to see whether it lists the sump capacity. I don't remember the service manual & parts lists being that expensive. I also ended up getting the full set on CD too.

The sump looks right, at least it looks like the original sump which was on my XK150. I don't know about the MkVII/VIII but the later saloons had a cast alloy sump which is much wider and won't fit between the chassis frames of the XK. The other sump which you can use is the one of the J60 military variant of the 4.2 engine. The original XK sumps do look like they were made out of a couple of bits stuck together.

If you're rebuilding an XK140 you might find the forums on Jag Lovers to be helpful, I've not been hanging out there since I sold my 150 but they were helpful whenever I need to do anything.

[droopsnoot]

Thanks for that. I'm not rebuilding it, my mate is, and unfortunately he doesn't "do" computers in any way. Look forward to any confirmation you can give on the sump side of things.

[lowdrag]

24 pints, or 3 gallons for the MK VII in UK imperial measures. Be careful about the dipstick length too. We once had someone who kept topping the oil up on a regular basis - until he found out he had the wrong dipstick and had been overfilling the sump.

Edited by lowdrag on Monday 17th October 11:16

[Allan L]

I looked at Newnes Motor Repair and, as I expected, it doesn't give oil capacities.
A block would be marked "3 ½ litres" to distinguish it from one marked "2 ½ litres" and would refer to engine size, not oil capacity I'd say.
This is "lowdrag" territory not mine so I'll get out of the way.

[lowdrag]

If you want further info on MK VII specifcations this might come handy. It is from the USA and 5 pints UK equals 6 pints US:-

https://mossmotors.com/jaguar-mk-vii

[droopsnoot]

So, are you saying that it's a Mk VII sump as well as being a Mk VII engine, so it would be safe for him to take the specs from the Mk VII? Or is the XK140 sump pretty much the same capacity anyway?

Allan L said:

A block would be marked "3 ½ litres" to distinguish it from one marked "2 ½ litres" and would refer to engine size, not oil capacity I'd say.

Yes, I'd taken that as engine capacity, nothing to do with the oil. Sorry if my original post suggested that was the case - I was just intrigued that it's 3.4, and rounded to 3 1/2 on the casting.

lowdrag said:

24 pints, or 3 gallons for the MK VII in UK imperial measures. Be careful about the dipstick length too. We once had someone who kept topping the oil up on a regular basis - until he found out he had the wrong dipstick and had been overfilling the sump.

That's the main issue, as he doesn't have a dipstick at all is just how to figure out where to mark it.

Edited by droopsnoot on Monday 17th October 12:33

[GoodOlBoy]

I'd suggest that the level of oil in the sump, relative to the internals, is more important than the capacity of the sump.

If you make assumptions regarding the capacity you could end up with an oil level either higher or lower than is desirable.

Personally I'd get hold of the correct dipstick and fill the sump to that level. It may well be that several iterations of the XK engine use the same dipstick level.

Any specialist worth their salt should be able to advise you which dipstick to use.

[droopsnoot]

GoodOlBoy said:

Personally I'd get hold of the correct dipstick and fill the sump to that level. It may well be that several iterations of the XK engine use the same dipstick level.

Any specialist worth their salt should be able to advise you which dipstick to use.

That sounds like a good idea, but I'm doing this on behalf of someone* who has been told that the correct dipstick is difficult to find. On the face of it, given how many XK engines were built, that sounds unlikely to me. But if that does look like a Mk VII sump, maybe that makes it easier to find one. Doesn't that make it more important to know exactly which sump it is though? I am presuming that it's the different sumps that make the different to which dipstick is required.

( * meaning that I don't know anything about XK engines, and am just going to pass this advice back to him for him to take or not take as he wishes).

[GoodOlBoy]

I would imagine that the length of dipstick protruding into the sump is unlikely to differ much between engines of the same period i.e. Mk7 and XK150 etc. The length outside the sump may differ (I'm speculating) due to the differing engine bay configurations.

This may help.

http://coventryautocomponents.co.uk/store/c13277-x...

http://coventryautocomponents.co.uk/store/c8781-xk...

https://www.ebay.co.uk/itm/265935593979

[lowdrag]

This would seem to be the correct one, but it is nearly 20 years since I sold mine so memory fades. but this seems to be the thing.

https://mossmotors.com/oil-dipstick-2

This company is now running stock down since the proprietor died, but worth a call:-

https://worcesterclassicspares.com/mk-vii/

[harrycovert]

Just measured mine from shoulder to high mark 21.5 cm shoulder to low mark 23.2 cm
Part# C8781

[a8hex]

A quick search brought up

https://forums.jag-lovers.com/t/xk140-and-xk150-di...

It seems that there are different dipsticks used on different XK140s.

[droopsnoot]

Thanks for all the responses and links, I will collate them and pass them on.

[NMNeil]

droopsnoot said:

I know we have some Jaguar aficionados on here, so I wondered if anyone could help on this.

A mate has recently bought an XK140 project car in "to be rebuilt" condition, and it's come with an XK engine that has "3 1/2 litre" cast into the side of it. Is that normal for a 3.4 engine? I've had a look around and it seems that the engine number starting with "N" means that it's from a Mk VII or Mk VIII car originally, which would make it 3442cc.

Like the old BL engines were 998cc for a 1 liter engine and 1098cc for an 1100.
I believe it went back to car insurance and road taxes. Many countries have tax bands for different sized engines. You taxed and insured a car with, say an 1100 engine but in reality it's 1098. The maximum it could be overbored would add the extra 2cc bringing the capacity up to the 1100 mark, which meant it was still within the taxation and insurance requirements.
I may be wrong but that's what I was told way back in the mists of time

[Pantechnicon]

If he does find the correct capacity (shouldn’t be hard from a specialist) and then goes down the fabrication route it would be an idea to fill with a litre less to start with to give him a minimum mark the add 1/2 Ltd to give next mark etc

[harrycovert]

Found this in Bernard Viart XK 140 Explored
May be some help
IIRC My 140 basket case was missing the dip stick and I got one from Ken Jenkins for about a £5 was some time ago.
Very knowledgeable guy and very helpful As is Tom Kent in Sussex anther good source of XK parts

[droopsnoot]

Thanks again.