Distributor Baseplates

[111Robin]

Apart from the connection for the vac unit being redundant, can a 25D baseplate be fitted to a 23D distributor ?. I have a 23D fitted with electronic ignition that I want to convert back to points but only have spare 25D distributors for parts.

[Hipwell]

Yes, well a 23d fixed baseplate fits a 25D, so don't see why not.

Long term the 23D two piece points(That pivot on a 3/16" brass pin fixed to the base plate) are better, NOS or Distributor doctor seem just as good.

[111Robin]

Yes, well a 23d fixed baseplate fits a 25D, so don't see why not.

Long term the 23D two piece points(That pivot on a 3/16" brass pin fixed to the base plate) are better, NOS or Distributor doctor seem just as good.

That's great, thank you.

[Spider]

You'll want to lock up the plate in some way as without the Vacuum Advance fitted, the top part of the plate will be free to rotate quite a few degrees.

[NickD]

And you will have to file some recesses in the lower section of the 25D baseplate. The distributor bodies have 2 internal bosses to support the baseplate and these are taller on the 23D body than on a 25D, so a 25D baseplate will sit too high up within the 23D body unless modified to clear these bosses. (Conversely, a 23D baseplate will fit in a 25D body without modification – it just won’t be supported by the lower 25D bosses).
Alternatively, the Distributor Doctor sells new 23D baseplates.

23D v 25D.jpg

[111Robin]

Thanks folks, I'll probably just get a new plate to make certain it's correct.

[Hipwell]

You'll want to lock up the plate in some way as without the Vacuum Advance fitted, the top part of the plate will be free to rotate quite a few degrees.

Very true, seen this before where a blob of weld (to solve the problem) had broken free. Ideally you would phase the rotor arm in the correct place (Tip pointing at the contact in the distributor cap as the points begin to open) before looking it too.