I pulled the engine and tranny out of my V from the top. I had the head off but still had the shifter in it which made it a bit more difficult. The manual says to take it out the bottom but I didn’t have a lift to put it on.
As a side note, a friend from Texas has a family which were Jaguar collectors back in the ‘80s and ‘90s. He said there was a company that would drive around that part of the country in a panel truck with several different engines inside. They would come to your house, pull you engine and drop in a rebuilt one for a fee. They’d then drive off with your engine and rebuild it for the next use. He said they had this done several times. Wouldn’t that be nice now!
Not very good for the “matching numbers” brigade.
Perhaps they could be called “marching numbers” cars instead.
Peter
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I guess everything is a compromise. I was thinking of upgrading my 2.5 to a 3.5 before I put all this cake into the 2.5. I settled for a tranny with an overdrive.
I remember some discussion about them in the early days of jag-lovers, might have used the name Crow, shady characters, camped out on the front lawn and chugalugged all night, no guarantees, the kind several said were glad to see the back of them.
What type of gearbox are you going to use? There is a man in South Africa who fitted a gearbox and overdrive from a MKVIII into his MKV. He was going to post photo’s but just seemed to disappear before he did, sadly. Anyway, just out of interest I’d like to see how you fit it and what you do with the wiring?
Tim
I guess different people received different service or different crews. My friends family had several 120’s and a couple 140 &150’s plus newer sedans. At one time they had 12 Jags in the fleet. They had several engines replaced or rebuilt on site. My friend talks fondly of it to the point where he said it was too bad they weren’t still around and in the East to help with my recent problem finding proper sized rod bearings.
I have past that problem with +.04 bearings instead of +.02…just a bit more grinding. It would be wonderful to have a traveling machine shop come by with parts and or a replacement engine.
Hi,
How did you find room for an O/D in a MKV? Or a MKIV?
And talking about compromises, design wise the 3 1/2 Litre has more compromises. Having now taken the head off three times and rebuilt the complete engine once, I can see what Ed meant with the 2 1/2 Litre engine being a better design.
The inlet tracts in the head and the amount of head bolts as the much higher torque they have. So if one would desire a higher tune, you could use higher conpresssion, higher revs or even supercharge the 2.8 litre unit. On the 3.4 litre it would not work as well and more easily blow the head gasket. And in there I deliberately use the more accurate metric displacement instead if the “two and a halfish” they used in the past, and not confusing with different later XK engine designs.
Cheers!
Hi,
So I guess the 2 1/2 Litte is different then? On my 3 1/2 Litre I used normal XK con rod bearings, +0.040” oversize, just like the previous ones were, the journals only received a light polish, just the main journals were cut and now use the Clevite Chevy 350 mains in -0.020” undersize. The problem before was that I had to compare original versus current main journal size and the line bore diameter if the original Jaguar spec vs the Chevy spec, but once it was all clear the rest was pretty simple.
Cheers!
The 3 1/2 used the same mains as the 2 1/2 so the Chevy 350 trick is common but the rod bearings are not quite so well served.
Peter
In an odd reversal, of sorts, when Dad rebuilt the Auburn’s Lycoming straight 8, he wanted to do away with the poured rod bearings, due to their constantly needing shims removed and short life (110 mm stroke will do that!).
A bit of measuring, some simple machine work, and Jag XK rod bearings worked.
Yes, we’re still looking for a substitute modern or common rod bearing for the 2-1/2 Litre. I’ve been gradually going through the Clevite catalogue.
The parameters as given in the Mark V Manual are:
OD = 2.000 +0 -.0005" (50.8mm)
ID = 1.896 to 1.895" (48.16 to 48.13 mm)
W = 1-3/16" (30.16 mm)
As I recall, Crow mainly did engine swaps in the 1970s XJ6 Series 1 & 2, which had quality problems and often dropped valve seats when severely overheated. Another common solution was swapping in a small block Chevy V8, for which the British slang term is a lump, which is why we have a Lumps forum here on jag-lovers.
Seems there was to be a lot of changes needed to put modern Chevy bearings in my MK V 2.5L engine. The mains were fine but the rod bearings were worn half way so needed replacing.
As for the overdrive, I tried to find a place for it using the original tranny but there wasn’t a good location giving proper prop shaft movement. I found a late ‘70’s Volvo transmission with the Lovecock overdrive in very good condition. I made an adaptor plate out of 3/4“ aluminum and bolted it all together. It comes out 11/16” longer then the Jag tranny and there is room for that before the short propeller shaft.
I’m still working on the engine and stripping the car down to repaint so I haven’t been able to check exact fit and build a new mount as yet. Once I have the engine compartment cleaned and sanded, I’ll check the fit before painting. We’ll see what compromises I’ll have to deal with at that point.
Keep researching: there has got to be some shell that can be utilized… perhaps a letter to a major manufacturer?
So, you’re saying that Chevy main bearings will fit my 2.5L engine?
Hi,
Yes and no. The original dimensions are different, but so close that they can be used.
In the case of my MKIV 3 1/2 Litre engine the block needed to be line bored. I have the exact measurements in a book at the garage, not home, but the cut was ca. 0.2mm in diameter.
And the undersize of my crank was -0.040” in Jaguar size which equalled -0,010” in Chevy 350 mains.
Also in order to use the Chevy 350 rear main bearing required ca 0.10mm to be cut from the thrust surface on both sides of the rear main bearing buck and cap.
But now I am glad it was done. 
Cheers!
Ps. But it seems unfortunately there is no known substitute for the “big ends” of the 2 1/2 Litre. I think for the 1 1/2 Litre four cylinder Ed’s reccomendation was to use some Mazda pistons and Triumph con rods and bearings, or was it the other way? Aren’t Standard and Triumph cars related? Over here I heard some Saabs share con rods and part of the valve mechanicals with some Triumph models at least regarding dimensions.
Only example of that I’m aware of, is the '70-~'80 SAABs, and the '75-'80 TR7s.
Ahhh, that must be it. Saabs were very common in here in those days, TR7’s not so much.
Cheers!