XK140 Distributor rebuild

In November 2018, I received a lot of help and advice regarding starting an XK140 engine. I have not been abe to get back to work on it but started yesterday by removing the distributor with the great advice of Paul Wigton aka Wiggles. The dizzy is a DVXFA 40199E. My plan was to remove it and install new points condenser and rotor. Once I cleaned this up this afternoon and inspected it, I find frayed wires in several locations, the very fine wire used to connect between a moving advance plate and the non-advancing world. The vacuum capsule is also very old looking although it doesn’t the mechanical weights appear to be free and oily. I called CXKs about getting an exchange rebuilt which used to go for $175 but then longer do that. Can someone recommend a US rebuilder of distributors this old? Thanks, Mike Moore

If you are not into authenticity buy a Pertronics dizzy. It does not have points thus eliminating a tuning variable. XKs Unlimited currently has them on sale and is including a free coil.

Pat H

You may consider Advanced Distributors, http://advanceddistributors.com/wordpress1/

Thanks Pat,

I have several reasons I don’t want to use a Pertronix, one being the worries I have trying to trouble shoot an ignition system and leaving the key on too long. The other is authenticity but no for the reasons you may think: I find it always great to have a car which matches the shop manual
v/ r, Mike Moore

Roger, do you know what they charge for a DVX 40199E? There sure are a lot of pieces to it!

Thanks.Mike Moore

What’s your skill level? Maybe you can do it yourself.
The flexible wire can be found with some of the parts sources for MG and TR.
Note a potential problem with the vacuum advance described in this thread.

Rob, I found this distributor to be a nightmare to remove. The clamp ring is a double clamp ring and it had been severely overtightened and rotated (?) then tightened again. It effectively wore two very deep grooves in the diss body. Even after I removed the clamp ring nut and bolt (wrong parts also) and forced the ring wider with chisels inserted in the gap, it was not possible to slide the diss body up through the clamp ring. I had to remove the single bolt which held the clam ring to the block. I found the problems there were that the diss was too close to the block for my crow foot 7/16 socket, and I couldn’t t geta grip on a 7/16 spanner. Wiggy put ,e on to bending up a special wrench which was terrific. My strategy is that I want to put a diss in which has had the points adjusted and has been tested and not have to get back into that hell of removing the thing again, I have been talking to British Vacuum Unit in New Hampshire and Robert can rebuild and sleeve the body plus curve the diss for modern gasoline for ca. $250 . I shall focus on getting the wheel back on the car meanwhile Thanks, Mike Moore

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Advanced Distributors charged me a little over $300 with freight for a DVX6A (no vacuum advance) a little over a year ago and this included re-manufacturing a part which is no longer available. It is still sitting on the shelf waiting for a working engine (so am I), but AD also rebuilt a distributor for my E-Type which works flawlessly.

Hi Mike, the website has both email and phone numbers for you to call or write to discuss pricing and details. Cheers.

British Vacuum Unit…as others said…I had a 40199e rebuilt…a bit more modern curve for todays fuels and spark plugs…perfect work. Replace primary wires next…with zero resistance wire. Nick

Nick, I just had a note from BV and my dissy will be coming back tomorrow, also recurved

I did wires and plugs, hope that does the trick,

Mike Moore

it is a good time to double-check/verify that timing marks are true top dead center…then set distributor to the advance you want–often the distrib rebuilder will make a recommendation…make a nice white paint mark on your desired mark…once the engine is happy with it. There’s always been a lot of forum discussion on how the distributor drive dog lug fits into the drive slot…which is very slightly off set to one side. Hope your start up is just fine. By the way, my XK120 is set up with .016 points, plugs are NGK BP6ES at .025, timed at 10 degrees BTDC. I run no ethanol 92 octane, add some Instead of Lead type additive, and Techron, and a few drops of Marvel oil. The Engine oil is with ZDDP. Nick

In a message dated 7/16/2019 9:24:15 PM Pacific Standard Time, noreply@jag-lovers.com writes:

July 17
Nick, I just had a note from BV and my dissy will be coming back tomorrow, also recurved

I did wires and plugs, hope that does the trick,

Mike Moore

I am planning on taking the rebuilt distributor over next week and plugging it in. I have a nagging curiosity though/ We had a devil of a time removing the old dissy because it had apparently had the clamping ring tightened and distributor body force rotated so much for so many time for so long that there were two very deep grooves in the body of the distributor , and the clamping ring had been tightened so tight the gap was fully closed and the original; tightening screw bent because of the angle it developed with a fully closed clamp ring, Even by removing the clamping screw and spreading the ring as best I could, thinly way out was to remove the inaccessible screw which attached the clamping rioting to the block. Thanks to Paul Wigton and a sacrificial wrench, I finally made a "special " wrench and removed the rear bolt.

The clamping ring is a double folded part in that there are two different rings formed of the same piece of metal folded around the tightening screw. Every clamp ring I have seen (TR3 and E Type and another 140 had a single plate clamp ring. I really do like for things to be as they came from the factory. After I tried to straighten the scre,w the threads
are deformed enough that the screw is hard to turn, I really need a new screw but it is a flanged (?) hex head with a screwdriver slot. Does anyone make those?
Also one would think you would want the head of the screw facing the access port in the FR wing but instead, it faces the engine and has to due to the square nut notch in the clamp ring,
I may be idealistic, but I have this vision of a nicely fitting distributor twisting easily in a smooth fitting clamp ring that a small amount of torque on the clamping ring screw will lock it up and it will be perpetually easy to set the timing!

Thanks for the help Nick

I do not have a photo of the original type distributor clamp and the screw/nut…perhaps someone does? Yup…on the 120 the clamp nut is inner…close to the block…and I had to find a wrench…bend it a little, then rind it quite thin…and then it is a work in the blind…upside down and backwards process…no wonder someone just left it tite and with muscle turned the dizzy. Definitely a PIA. Nick

That clamp ring with the square head bolt is used on every XK engine (but there may be different sizes?) and is almost never wrecked, so every dismantler like Jaguar Heaven or Welsh or Coventry West should be able to sell you one. 7/16" (across the flats) SAE size is correct; I use a thin wall box wrench on it.

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@MichaelPMoore, I’ve got a few spares, off my Rovers, if ya need one.

I’ll be leaving town this coming Saturday, the 28th, so can’t get it to ya soon.

I wonder why they have the bolt head on that end, Seems like oy is backwards for fender access,

Thanks Paul, I’ll be installing it next wee, I appreciate the offer though,

And I believe the distributor clamp nut may be the only nut on an XK120 with coarse threads. In the English language a coarse file is known as a “bastard” file. I think of this inaccessible, backwards-facing, blind nut as the “bastard” nut.

Here’s how I resolved the situation. I welded a new bolt to an original clamp so the nut would be reversed and face outwards for easy accessibility. The nut is one inch long so it’s easier to feel in the blind. But I retained the coarse threads so I could continue calling it the “bastard” nut for old times sake.

I have one extra of these modified XK120-140 distributor clamps. I’ll throw-in the original nut and bolt in case, someday, you come down with a bad case of originality fever.


Thanks Mike, I have thought about filing/grinding/sawing the side your new belt head is on so the notch will catch the nut and then add a spacer on the factory noted side.