Ignition timing advance/retard

[Tim Hooper]

I have a Type BW112 Model DK4A distributor and can’t see any sign of springs etc. for retarding the ignition when the engine is reving.  The manual advance/retard mechanism has been dismantled. Please see attached the photo.Can anyone assist?    

[AustinWood]

The advance/retard mechanism is below the bakelite mounting plate for the points. It can be removed by undoing the two screws close to the clips that hold the cap on.

[Tim Hooper]

Good afternoon Jim,
Can this be removed and replaced without altering the timing?

Regards, Tim

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Jim,
Itchy feet and took it apart and all looks food.
Thanks for the guidance.

Tim

[john williams]

There is no need to remove the base plate to check springs are working. If you can rotate the rotor arm a small amount in direction of rotation [by hand] and it springs back when the rotr arm is released, everything is as it should be. Ocaasionally, the distributor cam can become siezed on its' drive shaft,if you cannot get a small amont of rotation of the rotor arm by hand, the shafts are siezed.

[Tony Griffiths]

I find that reconnecting the manual advance and retard helps one to imagine that playing with it has a beneficial effect. As David Wortley once pointed out, being able to do this sometimes gives the impression that an extra 1 m.p.h. has been achieved. One thing that does help on the all-manual distributer is to lock down at the full advance setting, the "bolt with spring" that allows the body to rotate. I used to do this for competitions but always reverted to the "wobble setting" for road use in the hope of sparing the crankshaft.

[Bob Culver]

Hi Tony

It is the variation in noise level that gives that effect. On my RP could shift over a huge range; engine noise level varied enormously  but  the top speed remained  the same. Manual advance gives you something to while away the time when climbing...or accelerating. With wear and springs of uncertain providence never really sure if auto advance is optimal (ie just as much as necessary for performance.)  
For cars converted it is worth retaining the manual as an override. Enables the optimum setting without use of the kitchen clock. A light spring on th linkage eliminates backlash.
Influences hill climbing more obviously.

[Tony Griffiths]

Hi Tony

It is the variation in noise level that gives that effect. On my RP could shift over a huge range; engine noise level varied enormously  but  the top speed remained  the same. Manual advance gives you something to while away the time when climbing...or accelerating. With wear and springs of uncertain providence never really sure if auto advance is optimal (ie just as much as necessary for performance.)  
For cars converted it is worth retaining the manual as an override. Enables the optimum setting without use of the kitchen clock. A light spring on th linkage eliminates backlash.
Influences hill climbing more obviously.

Hi Bob, yes, the coil spring - I'd forgotten that I too, at one time, used one for that effect. The other trick was to replace the 'shouldered bolt with spring' with an ordinary one and tighten it down just sufficiently so the distributer could still rotate - but with the slight up and down movement eliminated. A drop of light-duty Loctite on the thread ensured that the bolt stayed put.

[Reckless Rat]

On the other side of the coin, I have removed the linkages from the bottom of my steering column. The car has a Bosch dizzy, which is fixed although I left the adv/ ret connection in place just for show. The hand throttle I never used. After I took them off I was amazed at how much quieter it was in the cabin. The linkages were transmitting engine vibrations which were being amplified by the column tubes.