[xk] Distributor for XK 120

Help! When I bought my 120 FHC it had a Vertex magneto installed
instead of the original distributor. The purchase included a box of
assorted spare parts and in that box was a lucas distributor
(40576A) that I assumed was the original. Years later I bought a
new distributor cap for an XK 120 and I found that it wouldn’t fit
the one that came with the car. After researching the number found
on the distributor body (thank you Rob Reilly) I found out that my
distributor was actualy used in 8:1 compression ratio MarkVIII’s,
Mark 1’s, XK 150’s. Can anyone tell me if this thing will work on
my car? The engine number is W6939-8S. I believe the ‘‘S’’
designation means that I have an 8:1 compression ratio engine but
in order to add to the confusion, a note that was included to the
owners manual states that ‘‘slotted skirt pistons (9:1) have been
installed’’. Thanks for any info you folks might be able to give
me.–
Hal Craig
Richburg, SC, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

Hal;
The “8” at the end of your Engine Number tells you the engine came from
the factory with 8 to 1 pistons… The note in the owners manual states
these pistions were changed to the “slotted skirt” type… If the “9-1”
parenthetical is your addition, and not written in the owners manual, the
split skirt pistons could be 8 to 1 as well… In any case, enough years
have passed that the only way to know for sure what the compression ratio
is, would be to pull the head…
The “S” suffix of your Engine Number only means this engine was fitted
to an “SE” XK… The “SE” meant “Special Equipment” which basically amounted
to wire wheels, dual exhausts, larger valves and high lift cams. Details
can be found in the XK120 Factory Parts Catalog.
Charles #677556.----- Original Message -----
From: “Hal Craig”

Help! When I bought my 120 FHC it had a Vertex magneto installed
instead of the original distributor. The purchase included a box of
assorted spare parts and in that box was a lucas distributor
(40576A) that I assumed was the original. Years later I bought a
new distributor cap for an XK 120 and I found that it wouldn’t fit
the one that came with the car. After researching the number found
on the distributor body (thank you Rob Reilly) I found out that my
distributor was actualy used in 8:1 compression ratio MarkVIII’s,
Mark 1’s, XK 150’s. Can anyone tell me if this thing will work on
my car? The engine number is W6939-8S. I believe the ‘‘S’’
designation means that I have an 8:1 compression ratio engine but
in order to add to the confusion, a note that was included to the
owners manual states that ‘‘slotted skirt pistons (9:1) have been
installed’’. Thanks for any info you folks might be able to give
me.

Take a look on his table, you should be able to find the distributors you
want to compare.

Allan
679474

http://www.telusplanet.net/~chichm/tech/lucas.pdf----- Original Message -----
From: “Hal Craig” halos@chestertel.com
To: xk@jag-lovers.org
Sent: Sunday, November 06, 2005 7:49 AM
Subject: [xk] Distributor for XK 120

Help! When I bought my 120 FHC it had a Vertex magneto installed
instead of the original distributor. The purchase included a box of
assorted spare parts and in that box was a lucas distributor
(40576A) that I assumed was the original. Years later I bought a
new distributor cap for an XK 120 and I found that it wouldn’t fit
the one that came with the car. After researching the number found
on the distributor body (thank you Rob Reilly) I found out that my
distributor was actualy used in 8:1 compression ratio MarkVIII’s,
Mark 1’s, XK 150’s. Can anyone tell me if this thing will work on
my car? The engine number is W6939-8S. I believe the ‘‘S’’
designation means that I have an 8:1 compression ratio engine but
in order to add to the confusion, a note that was included to the
owners manual states that ‘‘slotted skirt pistons (9:1) have been
installed’’. Thanks for any info you folks might be able to give
me.

Hal Craig
Richburg, SC, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

Hal,
The short answer is yes it will fit and work, the car will run, and probably
pretty well.
The plus is the cap, rotor, points and capacitor are cheaper than for 120.
The long answer is it will not be ideal, the advance curve will be a bit
off, but how far off is unknown. It will have been set up for a different
combination of carbs, cams, air cleaners, valve sizes, head porting and
piston compression.
BTW what is your chassis number?

I see that distributor list in the library is over 8 years old, and a few
minor corrections are needed. Is Ted Uiterwyk still with us?
Rob Reilly - 679187

lucas distributor (40576A)
Can anyone tell me if this thing will work on
my car? The engine number is W6939-8S>a note that was included to the owners manual states that ‘‘slotted skirt
pistons (9:1) have been installed’’
Hal Craig

In reply to a message from R, J, G K Reilly sent Mon 7 Nov 2005:

Rob, thanks again for the application list you posted awhile back.
The chassis number on my car is 680505. I’ve had it since 1972,
drove it for a couple of years then parked it. The car has been in
my last four garages in various stages of disassembly since then.
If the gods allow and the distributor cooperates, I hope to start
the motor for the first since '72 in a month or so.–
Hal Craig
Richburg, SC, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

Hello. I need a distributor hold-down clamp for my XK120. Will this work? It says this is for six cylinder motors from 1958 forward. Thanks you.

john

I can’t see why it wouldn’t.

And now I see why it might not!

Not a direct fit. The diameter of the DVXH.6A used on the pre-'58 models is 1-1/2" at the place where the clamp fits, where the DMBZ.6A used on '58 and later models is 1-7/16" there.
Jaguar Heaven in Stockton might have one off a Mark VII.
If you don’t have any luck finding an original, a machinist could open up the ID on that Moss one.

Thanks Rob. So, if I understand you right the only difference is 1/16" where it chokes around the distributor shaft? If that’s all it is then I can get the Moss item and open it up and make it work. What about the location of the lockdown bolt hole? Is it the same in both?

This is my distributor and the shaft measures 1-1/16" in diameter.

john

The position changed, but I think the radial distance from the main shaft is the same.