Distributor backdate

[8adgerx]

Can anyone give me some advise. 
I would like to go back to a points distributer removing all cdi etc. The car is a 81 us import, are there any replacements available ??

 

[Leicestershire]

Difficult on the SC as the distributor spins in opposite direction.

Do you mind me asking why you would like to backdate this part?

[Jonny Hart]

2 hours ago, 8adgerx said:

Can anyone give me some advise. 
I would like to go back to a points distributer removing all cdi etc. The car is a 81 us import, are there any replacements available ??

 

So that you can have less power, harder starting and endless fiddling with points gap and timing?

If you are insistent on returning to the days of yore, you can use an early clockwise distributor and replace the gear with the SC one but the fun doesn’t stop there...

Because the distributor is turning the wrong way, you need to rephase the points so that they open when the rotor is pointing at the post cap.   You can do this by unscrewing the points base plate and moving it round - new screw holes will be needed in the dizzy body.   Unfortunately this now clashes with the vacuum advance mechanism  so you won’t be able to use that.

Finally, you will need to recurve the weights and springs so they give the same kind of curve as the SC.   Most early cars run much more advance than the SC so the curve is not suitable.

For the record I have done the above but purely for test purposes during the development of our CDI box.   I wanted to understand how points bounce when they are not adjusted correctly.

You asked for advice. Don’t do it!

 

[tea boy]

Why don’t you go all the way and convert it to steam power? 🤪

[Phill]

Does seem like a strange thing to want to do. Why not it some carbs on while you are about it and fiddle with those endlessly. 

[Jonny Hart]

I can kind of understand the thinking if you’ve come from a ‘normal’ classic car.  
 

The CDI system seems complex and expensive compared to just a coil, but coils need a set of points or a 12V square wave to charge them so this cannot be achieved with the SC distributor.  
 

People also draw the conclusion that inductive ‘coil only’ ignition must be better because that’s what modern cars have but that is mainly because inductive is better for lean burn engines.    
 

CDI is fitted to our cars in the era prior to better control of fuel introduced on the 3.2.  

I have actually run my car on an inductive system to try and debunk any myths.  This was way back when we considered designing an inductive system instead of the CDI+. Firstly, it was a pig to start the car, and  impossible if the plugs are remotely wet.  The snap throttle response was hesitant and the engine just felt rather lazy.  Higher RPM is noticeably down on power as the coil has little time to charge fully.

I have yet to see an SC distributor that has failed.  Very well made an super reliable.  

The early distributors are a bit more fragile.   There is also an issue due to the low quality of points currently available.  
 

 

 

 

[hagarep]

Are we talking about going back to a distributor from a 73 or earlier?

I have points and CDI in my car. Lumpy idle, and light throttle combined with very poor hot starting. I check the points gap once a year but never have to adjust it, with the mileage I do.

Would have fitted one of Jonny's boxes by now, but I have a long term plan to go throttle bodies and no distributor.

Jason.

[jehatwhitland]

I'm pretty old school and wanted my car to be as mechanical as possible (yes, I love fiddling with carbs 😉), but even I have CDI+ on mine! I completely agree on the inductive piece as well, the head and piston combination of most IBs needs a good strong spark to work properly.