Distributor drive gears ?

[30EK42]

Perversely, while everyone else is trying to upgrade their ignition system, I am attempting to downgrade mine !

I want to swap out the breakerless ignion system on the SD1 engine I have, and replace it with a contact breaker distributor from a P5B or P6.

I was talking to a guy who was selling a pile of V8 distributors, and he was telling me that the drive gears change at some point.
Any truth in this ?
Am I going to have to match my early distributor to an age appropriate camshaft ?
Or can the drive gears just be swapped over ?
Another increment on my Rover V8 learning curve ?

[harvey]

P5B & P6B had a driven gear on the shaft, and a male tang on the bottom of the shaft to drive the oil pump. On the SD1 (and onwards) that changed to a gear on the distributor shaft with a flexi joint on the bottom of the gear, to drive the oil pump that is female on the gear. You can fit the later gear assembly to the early distributor with a minor mod, but you can't do it the other way around.

[30EK42]

Thanks for that.
I'll just go and pull my SD1 dizzy now, and take a good look.

[DaveEFI]

Which ignition system does your SD1 have? The last one DLM, amp on side, is very good, but worth relocating the amp in a cooler place. Lucas did just this on later Range Rovers.

[30EK42]

I can't see any amplifier box on the side, so I'm assuming that its an earlier SD1 type.
I presume that there should be a seperate amp box for the unit I have ? (I don't have one)
In any case it's got to be 40 + years old.

Anyway, I'm going through a sort of "Luddite" phase at the moment.
Said V8 is going in a series Land Rover
Points ignition can always be fixed in a difficult situation, not so easy for dodgy old semiconductors.
I have the requisite strobe lamp for timing up.

Later on I may adopt a breakerless system, but only something very basic.

[DaveEFI]

You need to identify which system you have. The first Opus system can be unreliable, but also can be fixed. Not sure I'd want to go back to the old oil pump and drive - BL likely modded it for a good reason. Single points on an 8 cylinder engine are pushing their luck. On my P6 it was nearly a monthly job to keep the dwell correct - and that on a fairly new car, so not a 40 year old dizzy. There are after market electronic systems that should fit your distributor if it is otherwise good.

[30EK42]

Yes, you're probably right about a single set of points struggling to cope with eight cylinders.
Especially on a 50 year old half worn out distributor.
I like theidea but it may be somewhat impractical in reality..

The long term answer has got to be a nice new modern trigger unit plus amp box.
Back up unit kept in the vehicle as a strategic reserve.

[DaveEFI]

I now have EDIS, but the amp on the side of the DLM did fail a couple of times in the 30 years I've had my EFI. But an easy job to change at the roadside, if you carry a spare amp. Much easier than fiddling with points.