35D8

Duel advance & retard


New products and services. Advance, duel and special vacuum units.

​britishvacuumunit@isp.com

Highly sought after in the past.
Lucas 35D early advance & duel advance / retard vacuum units.
Aston Martin, Bentley, Rolls Royce, Triumph Stag & TR8, Early Rover and MGB V8 Etc
As original with stamped part numbers and code.
New improved retard castings with double lip Viton shaft seals.
HD diaphragm folded around pressed edge.
Made to hold up to extreme temperatures.

​British Vacuum Unit, which is not affiliated with ZF Friedrichshafen AG, the owner  the US trademark for Lucas®.

Early 35D8 tin units

pin link

Our BVU Delco D204 advance unit
replaces the old Delco advance/retard and retard units

We not only re-manufacture all OE units to spec.
Proper part number, code, casting and fittings.
We also re-manufacture many special advance units
greatly enhancing performance for cars like the,


1971-76 TR6 Lucas 22D6   5 13 10 special vacuum advance.
Gives early TR250 vacuum advance performance.


Cars equipped with the 32/36 down draft Weber
Special Lucas DM, 22D6, 25D4 and 25D6  8 18 10
The down draft Weber can hold as much as
5-6 hg vacuum at idle causing a snow ball advance at idle and retard when the throttle is opened.
Our 8 18 10 often completely eliminates the hesitation and sneezing problems and enhances higher speeds.

1973-74 MGB / Midget
54425359 10 15 5 manifold vacuum
Original in appearance but manufactured with OS diaphragm folded into the pressed outer edge to prevent pull out!

New Delco D204 Replacement vacuum advance units.
2 screw / Pin link simple and easy to install
Early non emission 8 18 10 or 5 13 10 spec for ported vacuum. Direct replacement for the duel and retard units on the 7992101, 7992198, 7953547 Delco distributors.
We machine ported vacuum on Zenith carburetors that were not completed from the factory.


We are working on a new vacuum unit for supercharged cars!

Lucas DM2P4, DM6, 22D6, 25D4 & 25D6 
You run your required mechanical advance. Possibly now a few more degrees!
Using manifold vacuum as a source, under boost “pressure” the vacuum unit retards the timing the 2, 4 or 6 degrees as required.
High speed cursing "not under load", manifold vacuum regulates vacuum advance.
This vacuum unit has a fixed center with pressure retard and vacuum advance all in one.
Contact me if interested.

​britishvacuumunit@isp.com

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