The largest and best supported Jaguar cars enthusiast site on the Internet!

Serving Enthusiasts since 1993
The Jag-lovers Web

Currently with 3,166 members

Lucas CEI Distributor

Jaguar V12

Lucas Distributors


As reiterated over and over in the book and on the discussion list, the Lucas distributor tends to seize up.  Typically, the owner has made one of two mistakes: either he hasn't lubed the distributor regularly, or he has.  If the distributor hasn't been lubricated regularly, the steel rotor carrier shaft rotating on the steel distributor shaft without benefit of bronze bearings or nylon bushings has been rendered a solid block of rust.  If the distributor has been lubed regularly, the lubricant has been turned to varnish by the heat in this area and has locked the rotor carrier shaft to the distributor shaft.

The distributor needs to be overhauled and all the old crud removed and lubricated with clean synthetic motor oil to assure proper operation of the centrifugal advance mechanism.  It is recommended that owners tackle the job themselves, since most dealers or mechanics seem unwilling or unable to do the job properly; many will merely dump penetrating oil down the top of the rotor carrier shaft, wiggle it until it seems to loosen up, and pronounce the job done.  Of course, the unit promptly re-seizes soon thereafter.  If long-term trouble-free operation is the intention, disassembly is absolutely necessary -- even with a brand new off-the-shelf distributor -- to insure that the original lubricant as well as any grime or varnish buildup have been completely removed.

There is one other problem with simply dumping penetrating oil down the center.  Penetrating oils or solvents are often highly volatile and highly flammable, and the next time the car is started there is a little "pop" as the distributor cap is scattered all over the engine compartment.  This normally doesn't harm anything else, but you'll be upset paying for a new cap.

Since people unfamiliar with the Lucas distributor will need to be taking it apart, this site provides some pictures of the parts involved to help make the job clearer.

The Jaguar V12 was fitted with a Lucas distributor up to 1989, when the Marelli ignition system was introduced.  The early cars had an OPUS ignition system, which was replaced with a Constant Energy Ignition (CEI) system in 1982; both of these systems used a Lucas distributor and both have the same history of centrifugal advance seizure, but the distributors are slightly different.

Choose the link for whichever distributor you need to look at:

Lucas OPUS (1971-82)

Lucas CEI (1982-89)

In addition, there is a page comparing the two designs.

The Marelli (1989-94) is a totally different animal with a gutless distributor and the advance curves controlled by a computer.


Please help support the move to the new site, and DONATE what you can.
A big Thank You to those who have donated already!



Go to our Homepage
Improve your Jag-lovers experience with the Mozilla FireFox Browser!

  View the latest posts from our Forums via an RSS Feed!

Jag-loversTM Ltd / JagWEBTM 1993 - 2024
All rights reserved. Jag-lovers is supported by JagWEBTM
For Terms of Use and General Rules see our Disclaimer
Use of the Jag-lovers logo or trademark name on sites other than Jag-lovers itself in a manner implying endorsement of commercial activities whatsoever is prohibited. Sections of this Web Site may publish members and visitors comments, opinion and photographs/images - Jag-lovers Ltd does not assume or have any responsibility or any liability for members comments or opinions, nor does it claim ownership or copyright of any material that belongs to the original poster including images. The word 'Jaguar' and the leaping cat device, whether used separately or in combination, are registered trademarks and are the property of Jaguar Cars, England. Some images may also be Jaguar Cars. Mirroring or downloading of this site or the publication of material or any extracts therefrom in original or altered form from these pages onto other sites (including reproduction by any other Jaguar enthusiast sites) without express permission violates Jag-lovers Ltd copyright and is prohibited
Go to our Homepage
Your Browser is: CCBot/2.0 (, IP Address logged as on 18th Jun 2024 05:43:09