Any body know what jag engine I have??

[Parrotface]

Hi chaps,

I've bought an old modified Austin. I'm told that the engine is jag. Can anybody confirm which jag?

Mark

[psi310398]

Not entirely clear but I'd say an XK6 of some sort from the seventies? Can you see the number?

[Parrotface]

Can you direct me to where I will see the number? Thanks

[w824gb3]

That's the fabulous XK engine. Fitted to many different jaguar models from the 50s to the 80s. Came in several capacities. 2.8, 3.4, 3.8 and 4.2.

[Magic919]

Many of them came with three carbs and this seems to have just a pair. I expect that would mean an earlier engine, like you'd find in a 420 or maybe an XK (pre-E).

[fatboy b]

Magic919 said:

Many of them came with three carbs and this seems to have just a pair. I expect that would mean an earlier engine, like you'd find in a 420 or maybe an XK (pre-E).

XJ cars without injection had 2 carbs.

[Magic919]

That's a useful clue. I started to look for the fluted rocker covers and those were about during that era. I remember the smooth ones from my Dad's 60s Jags.

[psi310398]

The number of the XK engine block for earlier models is normally stamped on the horizontal above the oil filter and for later models on the left on the bell housing flange. Following the initial letter(s) there are generally four numbers followed by /7 or /8 or /9, which indicates the compression ratio.

HTH

P

[Parrotface]

A few questions gents.

Could this unseize? If so, would a re build after be worth doing? Are they an expensive re build?

If it's better to bin it, is it an easy job to put a replacement in?
Would you think it's a good idea to upgrade to a newer jag engine? If so, would it mate to e siting running gear?

[psi310398]

Impossible to say whether the engine is salvageable from here but if it is early someone will want. Replacement Jaguar engines and parts are plentiful and cheap as chips, although some specialist parts are becoming harder to find.

IIRC all the six pot Jaguar engines up to the AJ16 (mid-90's) are relatively easily interchangeable (in regard to motor mounts and chassis placement). Gearboxes mating might be harder.

[a8hex]

psi310398 said:

Impossible to say whether the engine is salvageable from here but if it is early someone will want. Replacement Jaguar engines and parts are plentiful and cheap as chips, although some specialist parts are becoming harder to find.

IIRC all the six pot Jaguar engines up to the AJ16 (mid-90's) are relatively easily interchangeable (in regard to motor mounts and chassis placement). Gearboxes mating might be harder.

The AJ16 has the inlet and exhaust manifolds the other way around compared with the XK.

[Parrotface]

Eeeek - looks like rebuild costs are way out of my league. Looking like a 4-6 k operation ;(

I am extremely embarrassed to ask this, especially after the old man owned e types and is sadly no longer around to pose these questions too, but why the big difference between the xk and AJ6

Xk are obviously a superior engine based on costs, but are the AJ6 very weak in comparison, not only in power, it lifespan?

My thoughts At this moment are to loose the xk- would an AJ6 mate to the running gear?

What potential ly could I move the xk on for as a seized unit?

Mark

[psi310398]

I'm not sure that the AJ6 is inferior, it's just more plentiful, so the laws of supply and demand are at play.

The AJ16 has a reputation for being bombproof and cheap to buy now but, as a previous poster has pointed implied, you will need to make adjustments to the exhaust system to make it fit. But if you are buying the engine, you can probably get the downpipes at the same time and do a bit fabrication. Obviously, other things might need to be moved around a bit.

How much your current unit is worth will depend upon what exactly it is, what state it is in and who is in the market at the time. I'd imagine a Jag owner's forum is the right place to ask if you find that it is uncommon.

HTH

Peter

[Orcadian]

What kind of Austin was it? Looks like an early model with a bonnet with central hinges and the XK Jag engine is not really doing the car any favours pricewise. As other posters have said, you have a XK six pot power unit there, double overhead camshaft with 2 valves per cylinder. Looking at that inlet side, it looks to be a later engine . Assuming it was transplanted as a complete unit it would be post 68 with those ribbed cam covers. Capacity could, as said be from 2.8 up to 4.2 - does it have a V5 with any details?
The AJ6 is an entirely different unit, all alloy, 24 valve, always injection and was fitted 'on the slant' so if you wanted one of those you would have issues with the sump and it would not mate to your box (is that manual or auto?)
As for price, as others have said, none are particularly rare and all XK units suffer from rotted head studs, which go down through the water jacket and erosion of the head gasket face - all repairable at considerable cost. Remember it's got six of everything!

Best to source an engine for the Austin - more value in originality for most people and get what you can for the old XK unit. Good luck getting it out from there, looks to have insufficient space to come out from the top and there will be a well stuck crossmember under it!

Regards,
Ian

[Jaguar steve]

Parrotface said:

Eeeek - looks like rebuild costs are way out of my league. Looking like a 4-6 k operation ;(

I am extremely embarrassed to ask this, especially after the old man owned e types and is sadly no longer around to pose these questions too, but why the big difference between the xk and AJ6

Xk are obviously a superior engine based on costs, but are the AJ6 very weak in comparison, not only in power, it lifespan?

My thoughts At this moment are to loose the xk- would an AJ6 mate to the running gear?

What potential ly could I move the xk on for as a seized unit?

Mark

Unless it's part of a very big budget restoration a seized XK engine is worth exactly what the scrapman will give you for it. You might try a speculative can of WD40 down the bores just for fun and see if you can get it going but even if you do you'll be getting into a whole world of terminal internal corrosion, snapped head studs and warped heads, failed gaskets, oil leaks and potential cracks in the block. Personally I'd just whip it out and abandon it as a neglected XK lump has got strong potential as a serious money pit

You could replace it with another running XK as you know it'll fit and you won't have to get into fabricating mountings and adjusting clearances and faffing about with electrics, cooling and fuel systems and exhausts as somebody else has already done that for you, and you know it'll mate with the gearbox and prop too. Eurojag spares might be able to help with one.

Although the AJ6/16 Jaguar engine is far more durable then the XK If you're going to stick another engine alltogether in then why not go for something like a 2.0 Ford Zetec or Vauxhall 2.0 Red Top? Both are easily tuneable for big power and both are far lighter and simpler than any Jaguar engine and there a whole mass of expertise and parts among kit car builders and the custom scene regarding getting conversions like those to fit and run well.

Someone somewhere will know exactly how to go about it.

[a8hex]

More thoughts
I can't tell from your picture whether it is a 2.8 or 4.2 XK engine you've currently got. I'm guessing that the smaller one isn't as tall, the 2.4 and racing 3.0L versions weren't.
The AJ16 looks to be rather larger around the head area than the XK, so you might have some space issues.
I few years ago I bought a 4.2 XK engine on eBay for £50. I bought it to dismantle just for practice. It was only when I had it in little pieces I realised just how good condition it was in. It certainly wasn't seized and in hindsight would almost certainly have run OK. You might be able to find one if you look.
Steve's suggestion might be an easier cheaper solution though, it's not as if the engine belongs there anyway.