I wanted to re-invigorate comments from threads of old, as I and some others have been looking at this unit perhaps because of the Nippyesque but narrow inlet-ed downdraft Reliant manifold which happens to have a vacuum feed. And also looking at hardy Lucas/UK made units for general use. I'd be grateful if anyone else with experience of using this unit, and particularly trialling the vacuum advance, might post here or make contact. Also of the Reliant manifold which is available reasonably cheaply but demands some work with the grinding stones. Thanks to Dave Wortley I found there was a last, festering, 40872 unit at Speedy Spares.
It is worth saying that there is a good deal of confusion in finding units which rotate the correct way as the Seven as the Lucas/Austin notation of rotation changed, probably in the 1950s. So we need CCW DK4A units (original notation, viewed from drive cogs) but now need CW units, viewed sensibly from above. The arrows on the units thus face to the left. The comments below also mention the 45D, which is a later upgrade (sic) with one bearing rather than two for the spindle.
Some quotes from earlier forum:
I have been using a Lucas 25D4 (40872) from Speedy Spares Services Ltd for the last 20 odd years on 2 A7's. They fit on without needing lathework and have vacuum advance. I fitted the first one because I couldn't get my pretend ulster with DK4 to rev over 4500rev/min without misfiring no matter what I tried.I even loctited the auto advance up solid. I think they were fitted to the Reliant Regal(Robin?) 600cc model. It's a long time since I fitted the last one and seem to remember it was a case of filing a little off the collar on the body of the distributor to obtain the correct meshing position of the skew gear.The distributor spigot dia was identical to a DK4. Except for the vacuum advance device I think they look more like an original than the Bosch (which is because they are Lucas. (Dave Wortley)
I always used the clockwise rotation Lucas 25D, advance and retard systems locked up and with new quickfit points for every race. They were fitted to early Reliant 600cc OHV engines. I’d like to use the Lucas 45D; it’s a much cleaner design with no vacuum advance/retard but so far have not managed to find a clockwise version. (Henry Harris)
Yes the Reliant distributor is a 25D4 for the Reliant 600cc. Apart from the rotation it's the same as a Mini or MM so all the consumable bits are readily available. Mine takes the quick fit one piece points GCS101, the earlier dismantled points don't fit as there's no pivot post. Good to hear it works well for others. Mine hasn't any vacuum advance - it didn't come with one - I've locked the rotating baseplate and a Glenmorangie cork sealing the body hole. (Dave Armstrong)
Re. the last comment, its interesting that the baseplates AND vacuum advances are available for peanuts from Accuspark. Whether vacuum advances are suitable generic for use on a Seven, I know not. But others might!
It is worth saying that there is a good deal of confusion in finding units which rotate the correct way as the Seven as the Lucas/Austin notation of rotation changed, probably in the 1950s. So we need CCW DK4A units (original notation, viewed from drive cogs) but now need CW units, viewed sensibly from above. The arrows on the units thus face to the left. The comments below also mention the 45D, which is a later upgrade (sic) with one bearing rather than two for the spindle.
Some quotes from earlier forum:
I have been using a Lucas 25D4 (40872) from Speedy Spares Services Ltd for the last 20 odd years on 2 A7's. They fit on without needing lathework and have vacuum advance. I fitted the first one because I couldn't get my pretend ulster with DK4 to rev over 4500rev/min without misfiring no matter what I tried.I even loctited the auto advance up solid. I think they were fitted to the Reliant Regal(Robin?) 600cc model. It's a long time since I fitted the last one and seem to remember it was a case of filing a little off the collar on the body of the distributor to obtain the correct meshing position of the skew gear.The distributor spigot dia was identical to a DK4. Except for the vacuum advance device I think they look more like an original than the Bosch (which is because they are Lucas. (Dave Wortley)
I always used the clockwise rotation Lucas 25D, advance and retard systems locked up and with new quickfit points for every race. They were fitted to early Reliant 600cc OHV engines. I’d like to use the Lucas 45D; it’s a much cleaner design with no vacuum advance/retard but so far have not managed to find a clockwise version. (Henry Harris)
Yes the Reliant distributor is a 25D4 for the Reliant 600cc. Apart from the rotation it's the same as a Mini or MM so all the consumable bits are readily available. Mine takes the quick fit one piece points GCS101, the earlier dismantled points don't fit as there's no pivot post. Good to hear it works well for others. Mine hasn't any vacuum advance - it didn't come with one - I've locked the rotating baseplate and a Glenmorangie cork sealing the body hole. (Dave Armstrong)
Re. the last comment, its interesting that the baseplates AND vacuum advances are available for peanuts from Accuspark. Whether vacuum advances are suitable generic for use on a Seven, I know not. But others might!