Another distributor question

[Jase]

My distributor has a knurled wheel with A and R on it. Is this for fine tuning my advance and retard?

 

Edited July 15, 2020 by Jase

[RobH]

Yes that's right.  Each graduation on the shaft by the diaphragm housing represents 4 degrees of advance.

Edited July 15, 2020 by RobH

[AndyR100]

my old grey-cells have always used 10-11 clicks of the vernier as 1 degree A/R adjustment.  Of course, i may have been mistaken with the exact number!

..... Andy

[Jase]

It’s useful, had quite a bit of pinking and slugishness initially. Going to fit electronic ignition today so hopefully it will improve the accuracy

[stuart]

1 hour ago, Jase said:

It’s useful, had quite a bit of pinking and slugishness initially. Going to fit electronic ignition today so hopefully it will improve the accuracy

Wont make any difference unless you get the timing right, take the base plate out and make sure the weights are free and the springs are still there.

Stuart.

[RobH]

+1.  There's no use in putting electronic ignition on a worn distributor hoping it will fix things. It still uses the mechanical weights and springs and the vacuum advance, so those have to be working properly before you start. 

[Jase]

Guys, I know but it will improve the accuracy of points, fit and forget.

[Andy Moltu]

Electronic ignition isn't a panacea for a totally knackered distributor but will reduce timing scatter and the gradual deterioration you get.

As part of fitting the module the ignition timing will need to be set anyway and it's is a good opportunity to do some checks, minor repairs and lubrication. At the same time you can check for slack in the bearing/bush( a little is OK) and if the bob weights have seized, or if the springs are still attached. Sometimes the eyes of the springs can be a bit loose on the "posts" and you can nip them a bit tighter with long nosed pliers to resolve the slack if present so that the advance is controlled properly by the springs.

Lubricate well and see if it sorts things.

 

[iain]

.........fit and forget that the basic instrument is in need of a professional rebuild. Save your time and spend your money getting it rebuilt by http://www.distributordoctor.com/.

No connection just a very satisfied customer

Iain

 

[RobH]

4 hours ago, Andy Moltu said:

Sometimes the eyes of the springs can be a bit loose on the "posts" and you can nip them a bit tighter with long nosed pliers to resolve the slack if present so that the advance is controlled properly by the springs.

Andy, I found this info on tuning distributors (link below) which says the stronger (secondary) spring should be loose.   Quote:

Because the primary spring is in control of the lower end of the advance curve, it must be in tension under static conditions. The secondary spring must be loose to allow the primary spring to work and produce the characteristic advance curve with two different rates of advance as shown.

Perhaps 'nipping them up' as you suggest is not a good idea?

http://mgaguru.com/mgtech/ignition/pdf/tuning_lucas_dist.pdf

 

[Jase]

All done and working much better, distributor was fine, points were in need of changing so that wouldn't have helped. All cleaned and lubricated.

 

Thanks