Terry
Well if that’s the case , it’s something else that has been modified. It has SS spinners now, and the ID plate shown is just a piece of metal with the 5 numerals stamped on it.
Hello
Ed has started a new game, spot the difference, I have come up with
Rear wheel spat cutout
No chrome strip on bottom of rear spat
Jacking point plug at rear of door?
Park lights under headlights
New Alto horns have been replaced by spotlights?
Rear view mirror
Rear bumper bar?
Greetings All,
Rob, Jaguar produced 2 MKIV's with XK engines originally installed back in the day. St. Skilliter stated that Jaguar had documented this. Tony Otolo, of Massachusetts owned one of them, if I remember correctly it was green and 4" was added to accommodate the engine.
Talked to him one day when I was looking for SS1 parts and the name rang a bell. NIce guy.Sure, but not MKIV’s, they were MKV’s, RHD Saloons and had a bonnet that was an inch longer (and the radiator moved forward) to allow room the the longer engine. Not that there’s much room there even with a pushrod engine! Anyone ever replace the later type heater pipes? 
Four inhes sounds like a lot, nice if one has survived, I think most are PO bodges, but Sir. William did use one of these XK engined MKV Saloons personally, although it was before he became Sir, so lets say Bill had one.
Cheers,
Pekka T.
Fin.
Greetings All,
Pekka you are correct on them being MKV’s and not MKIV’s, but they did add more than an inch, I have the article. It fit within the rails but the grille area extended, nothing radical like longer fenders to match.
Otolo’s was the one Paul wrote the article about.
One of these cars survives and there is a fair bit of info on both and has been covered in Jaguar World and on the old forum.
The 4 inches is I believe how far the radiator was moved forward the car remained the same
Probably should have started a new topic for this.
Allan Crouch covered the two cars very well in his book published in 2013.
RHD Mark V saloon 620004 registered HRW 488 was the factory test mule with XK engine W1003-7 which is the third engine off the line. The Experimental Department ran it through a lot of tests. Then they changed the engine to W1110-8 with higher compression, and for unknown reasons also changed the chassis number to 623173 and ran more tests. The standing quarter mile time was 20 seconds and top speed was in excess of 90 mph. Then it was changed back to the original chassis number 620004 with a third engine W1187-7 and sold. Crouch says it still exists but did not give any further information about it.
The other car was 623053 registered JVC 441 with engine W1130-7 for William Lyons’ personal use. Crouch has pictures of this one, with a 1.5" recess cut into the scuttle and the grille and radiator moved 2.5" forward, very close to the bumper valence, so the bonnet would have been 2.5" longer than standard. This one also still exists.
Any other XK engined Mark Vs about are not factory work, they are post-factory conversions.
Greetings All,
I should have specified it clearer.
The fenders were untouched but the bonnet length and firewall changed to accomadate the new radiator location.
Hi Pekka,
There is a photo of a quite well converted MkIV in the Wherry book.
Another with modified chassis cross member.
Here’s a MkV chassis with XK installed at the factory.
Peter
Hi Peter,
Yes, of course it can be done as it has also been done on some SS1’s and SS100’s, but I just meant that the ones referred to as “factory jobs” were the two MKV’s Rob explained in detail. Those two were quite natural, they were “test mules” just like the MKX’s in the mid-60’s that had the prototype quad cam V12’s. Unfortunately the factory did not sell the prototype V12’s in any cars, but of course a few engines did survive, like the one Neville built his XJ13 around.
The logical reason was that in a way the XK engine was intended for the MKV, but was “tested” in XK120’s, smaller volume made sense, until the MKVII was announced (in late 1950 I believe) although it did not really go into production until mid-1951 IIRC.
Cheers,
Pekka T. - 647194
Fin.
The factory photo of a rolling chassis with two trucks in the background is a standard Mark VII chassis.
The dirty XK engined LHD Mark IV must be a 2.4 with those downdraft carbs.
I stand corrected. I’m not at home just now and don’t have access to Skilleter’s book from where I copied the photo. I had labelled it as MkV but I now see the rather obvious MkVII steering wheel.
Thanks,
Peter
My son, you are forgiven, though to cleanse your carburetters you must say three Hail Billys. 
The steering wheel is not the clue, as both models use the same one, though different from the Mark IV. The differences are rather subtle; the shorter front extensions on the frame rails where the Mark V has bull horns to mount the bumper, the two radiator brackets where the Mark V has one, the rear jack socket just in front of the rear tire where on Mark V it is parallel to the frame rail, and the rear cross member below the frame rails where on Mark V it is above.
Here is my Mark V frame.
Hi,
Very interesting photos, all of them. The differences between a MKV and an (early) MKVII chassis are minimal, like Rob described. The engine is a typical giveaway! 
the radiator mounting and the rear jacking points are about the only things to see easily, and isn’t the rear body mounting also different? (The location on the frame?)
Cheers,
Pekka T. - 647194
Fin.
Thanks for fleshing out the chassis differences guys. I think I must be “losing it”. Back in 2011 I even had a half share in MkV and was well aware of the single bottom radiator mounting and the steering wheel design.
Peter 
As I noted on the “Jaguar Magazine” face book page some weeks back when the subject of XK engined MKV’s was raised and this picture was used this is not a MKV chassis with an XK engine fitted but a standard MKVII rolling chassis.
This has been proved above with the rob reilly pic of his MKV chassis
There is from memory at least one pic of one of these cars in the forecourt of the Jaguar factory I have found an add early 1950’s for one being sold at a UK caryard. One car certainly survives Texas maybe? the second love to know more and in fact love to know more on both cars and current whereabouts
terry
PS to really confuse this topic from its original heading I have a photo of the prototype MKV this is the new independent torsion bar chassis the MKV used but with the old MKIV body
Terry, I’d love to see this picture if you can scan it and if it is not under copyright.
Thinking about why the factory would change the chassis number of 620004 to 623173 and then back to 620004, I am going to offer a guess.
Where we classics enthusiasts think of the chassis as “the car” and the chassis number as the “identity of the car” and everything else as parts added to “the car”, the factory Experimental Department thought of it as Experiment No. 620004 and Experiment No. 623173 and kept separate work records of each. Then when they were done playing with it, the Sales Department looked at the chassis stamp and sold it as 620004.
Just a guess.
Back to the original question of this thread…
Here is 49049 with a Mark V engine which sold at RM Sothebys Monterey 2016 for $572,000 in what is described as better than showroom condition. The text writer believes the engine swap hardly affects the value.
Go to page 5 and scroll down.
As the buyer of 39064, I had done plenty of research and comparison of price points. SCM’s data base of auction prices help this kind of thought process. Plus I’ve tracked each private sale over the last couple of years that I could track, some where I was the “losing” buyer. The 3 1/2 engined #39000 series bring higher prices by 30-50% than the 2 1/2 litre #4900 series SS100’s. As in many things, “logic does not apply” to the price differential, but the selling price records speak.
So, in a narrow field of available 3 1/2 litre SS100’s, I’m happy with my purchase of #39054. But I’ll sure be watching the auction results for the ex-Garroway SS100 at Scottsdale. I had already registered to bid, so maybe I “saved” the cost of a trip. Stay tuned…
Of course this purchase is as a retirement project, and I’m already enjoying the chase for everything from shock absorber parts to correct fuel pumps to “silver-black” leather. Ultimately, enjoying ourselves is what really counts.
Dave.
Dave ,
I wouldn’t try to reinvent the wheel.
The solver/black leather was a Conolly speciality , but a 100 owner here has a car with the same colour upholstery and has had some samples made up locally.
VSA [ Vintage Shock Absorbers] in UK do the Luvax shock absorbers. The 100 had an arrangement where the resistance on bump was half that of rebound. You will need to specifially ask for this or they will do them the bump/ rebound the same.
This is a result of the SSs having an underslung chassis,
Hartford 506 M s can be bought new.
Modern SU pumps have a slightly different plastic cover over the points or whatever replaces them. But areavavailable
If you are planning to drive the car in war weather aaaaa petrol pump up the back will avoid vapour lock , It can still pump through the SUs withuout them being altered.