Please forgive me for this query, I’ve been gone awhile and could not figure out how to search the site. Does anyone know if Bernard Viart’s book (XK140 Explored) has the plates drawn to scale? Specifically, I’m trying to build a jig to support the OTS body for a restoration and the chassis drawings are not complete enough to determine all dimensions -if they are to scale, it should be no problem.
My impression from working on my 120 is that blueprint dimensions were targets rather than absolutes. That is, the cars rolling off the assembly line - if one call call it that for XKs - were not all dimensionally the same. Pp 42 and 43 of Viart’s 120 book depict how the roadster bodies were aligned for assembly on a jig, saying final shut lines were achieved by lead loading. Some gap variation is also expected from individual aluminum doors not being precisely the same - I read somewhere, perhaps in this forum years ago, that individual doors were selected for best fit from collections of doors kept on the floor. No indication what the +/- tolerance was but I don’t think you can use scale drawings as a basis for measuring dimensions with sufficient accuracy.
I used the frame itself as an assembly jig, sills shimmed and bolted in place and front and rear clips positioned and resting but not welded to the sill ends. Any repairs required to stabilise the front and rear bulkheads were effected in situ. I then mounted and shimmed the doors to achieve best forward gap with the A post, fine adjusted the positioning of the rear and front clips for best fit then, using a tape measure to confirm square, welded the ends of the sills to the rear and front clips. The majority of the bodywork followed so I could be certain to achieve best possible fit of all four hinged panels. Only then did I lift the body off the frame to effect final repairs.
I custom built the cockpit bracing with the body mated to the frame then lifted it off with the help of fellow lister Alan Dell.
Bruce, As co-author of XK140 EXPLORED I can tell you exactly.
All the line-drawing illustrations started life as photographs, which were then photo-shopped, and then converted to line drawings using Adobe Illustrator. One converted to a line-drawing, then that line drawing could be edited/manipulated as desired by hand, thus enabling it to be best presented as required for the specific purposes of each particular plate.
With the CHASSIS FRAME drawings, these started life as about six photos of sections I took, as my frame from my Sept 1955 OTS was stripped and sitting in my garage, but when I took photos I was restricted by garage ceiling height to get a full view of frame without considerable distortion. So I took I think six photos of sections of frame that after converting to line drawings, were then assembled as best possible to make up the complete frame. Unfortunately there was problems with alignment of the pieces and still some varying distortions that were corrected to a degree, but only to the extent of being an overall accurate representation. So relativities of brackets etc, will be reasonably accurate, but certainly not exact, and under no circumstances can you scale the drawing to make an accurate jig. Where dimensions are quoted, they are accurate, but XK140 EXPLORED was never meant to provide engineering drawings suitable to accurately make/reproduce parts. It allows you to identify existing parts, and the relative assembly of parts to assist assembly.
If you want to make a body jig, I am afraid you will need to get your own accurate measurements of an actual chassis or find a copy of the original Jaguar factory Engineering Drawing.
Roger,
That’s a great explanation and will save me a lot of frustration in that I won’t attempt to extrapolate the dimensions shown on the drawing to parts of the drawing that don’t have such dimensions. I do have my chassis and, as far as I know , it’s an unmodified original. I’ve had the car since the early 1970’s (in a barn pending time to work on it - about 2 months ago, the time came!). When I first got the car, I was somewhat active in trying to determine its early history (Sept 1954-1960); I was able to visit with the owners from 1960 on. It’s the #2 XK140 LHD OTS. After thinking for nearly 45 years that the original engine was gone, it was discovered that the block had the right number so it’s matching numbers after all.
We made 6 frames a couple of years back that suit 120 140 and 150
allows body work to be done and in fact the suspension to be fitted./
The are drawings of the 3 chassis 150 is useless but 120 and 140 drawings are dimensioned are in fact factory drawings.
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These are seriously useful, Terry. Are they available anywhere? These are way too small resolution to read, but I guess there are intellectual property issues somewhere along the line.
I had the same thought - are they available somewhere (or could they be)?
I’ve tried to get information on drawings from JLR and from the JDHT in the past, but despite having a friend there they won’t release ‘intellectual property’.
So how did they get posted here? Or, are they just available in the form posted, too small to be readable?
Yes it is extremely unfortunate that Jaguar Heritage trust won’t release this sort of information as generally a lot of it is already in the public domain.
XK120_chassis_drawing_2220KB.pdf (2.2 MB)
Oooooooooooh! Oooo la la! I don’t suppose you have that in a file DXF format? WAIT! That’s hand drawn, no DXF for an analog format!
Now that’s what I call a chassis drawing.
Thanks Terry. How relevant would that be to an XK140DHC? Most things apart from steering rack mounts?
no only pdf and from memory this drawing was supplied to me by someone on this forum
A combination of Dave Roper and myself. Dave has 679001, which if I remember correctly was driven in its first year by Bill Heynes, and a couple of full size copies of the print in poor condition were left in the boot. Dave sent it to me and I ran it through the scanner at my work and returned the original to him. It was so faint that I had to trace over most of the dimensions and some of the notes before it would turn out a readable scan.
This is what is known as a weldment assembly drawing, the purpose being to show where all the parts go that are welded together to make a chassis frame. Location of mounting holes are specified in relation to the front and rear axle centerlines, and there was undoubtedly a welding jig with locating pins at Rubery Owen on which they set all the pieces and clamped them down before welding them together. Note that it is the later version with the FHC/DHC front body mount and the later type engine and gearbox mounts.
We thought it would be useful for anyone making a rotisserie or repairing a chassis that had been cut apart or damaged, but not enough information from which to make a full chassis from nothing.
funny enough one doesn’t need to start with nothing a MKV chassis will do and then just a few parts need to be made!
The problem I have is that the 140 drawing is illegible, and it’s a 140 I’m restoring. The 120 drawing is excellent and clear enough to read - are suspension mounts etc. the same as 140?
Certain things like wheelbase, front wishbone shaft and rear spring attachment points and clutch operating shaft locations I would think ought to be the same.
Certain other things such as gearbox mounting, front and rear shock mountings, steering mountings and bumper mountings will be different.
I do not know about front engine mountings, whether they are the same as late 120 as shown on the 120 chassis drawing (but certainly not like early 120 mounts which were erased when the drawing was revised about 1952).
BTW I notice the holes in the side rails for attaching the 120 type rear shock are still shown on the 140 drawing.
these are not holes as such but a depression/pressing in the side wall of chassis rail so heads of bolts don’t protrude. Because these rear rail sections are identical and therefore same pressing they are there right through until the MKIX XK150
I think the most important dimensions for my concerns relate to the front upper wishbone fulcrum pins and possibly the radius arms, i.e. the lower wishbone pivot holes on the chassis underside.