points & dwell angle measurements: frequency?

[earckens]

How often should the points gap and dwell angle need to be measured for good practice?

[ianc]

If one fits electronic ignition, then about once in a blue moon, or when fuel formulation changes.

Ian Cornish

[RobH]

The answer depends on how many miles you do annually as wear on the points a mileage thing.  For a low mileage classic car It's easy enough to check it as part of a normal annual service.

 

[Rob Salisbury]

15 thou points gap will put you right in the ball park for dwell angle assuming a standard distributor, then advance timing until you get pinking ( or fastest tick-over) and retard slightly, this point will change slightly with different fuels, book figures for timing are nominal.

Cheers Rob   

[ntc]

46 minutes ago, earckens said:

How often should the points gap and dwell angle need to be measured for good practice?

To answer your question it’s every 3000 miles as per service manual 

[earckens]

My wife likes to keep the car as original as possible hence classic ignition.

Every 3000 miles, good to know; we do far less so that would then set me at once per year.

Many thanks for the advice!

Erik

 

[earckens]

Re. different fuels: I use consistently 98 octane with this Castrol additive. Once I took 10ltr. 95 octane in a quarter full tank, the car drove horribly, never again lower than 98.

[ctc77965o]

Points gap needs to be checked regularly, as points close-up the timing changes, so checking the points gap every few thousand miles.

Dwell angle is only important if you rev your engine to the rev-limit - dwell time ensures that the coil charges adequately at max revs, at all other engine speeds the dwell time is more than adequate even if the dwell angle is wrong  - so, in my view, dont worry about dwell - concentrate on checking the points gap.

[ianc]

As long as the parts inside the distributor have been purchased from the Distributor Doctor (Martin Jay), service intervals will be as per the WSM.

Martin has produced parts which are the equal of or better than the Lucas originals, but there are rotor arms, points and condensers available off-the-shelf which can only be described as rubbish, and will fail or will wear out rapidly.   Have a look at Martin's website for full details.

Ian Cornish

[mikej]

Dwell angle is a function of the points gap so merely checking the Dwell angle periodically is probably adequate (and very easy) if the result is the same as previous measurements then all is good BUT it won't highlight material migration on the points (the pointy lump on one and corresponding hole on the other). A feeler gauge soon makes these obvious as the growth on one point appears as a gap that's too small. As Ian says, the WSM is still the best guide to checking. I have had the same set of points for years and have no motivation to go electronic, none.  One item often overlooked is a sloppy cam shaft (the one with the 4 lobes on), the bronze bearing in the main casing wears oval and this can badly affect points gaps and causes poor idle. If you can woblble the shaft by hand then the bush needs changing.

Noting that other views are available!

MikeJ

[earckens]

1 hour ago, ianc said:

As long as the parts inside the distributor have been purchased from the Distributor Doctor (Martin Jay), service intervals will be as per the WSM.

Martin has produced parts which are the equal of or better than the Lucas originals, but there are rotor arms, points and condensers available off-the-shelf which can only be described as rubbish, and will fail or will wear out rapidly.   Have a look at Martin's website for full details.

Ian Cornish

Thanks a lot Ian and Mike, your input helps me a lot! I am checking right now with Distribution Doctor.

[earckens]

4 hours ago, ianc said:

As long as the parts inside the distributor have been purchased from the Distributor Doctor (Martin Jay), service intervals will be as per the WSM.

Martin has produced parts which are the equal of or better than the Lucas originals, but there are rotor arms, points and condensers available off-the-shelf which can only be described as rubbish, and will fail or will wear out rapidly.   Have a look at Martin's website for full details.

Ian Cornish

I just checked: my distributor is a Mallory double points distributor. I called Distribution Doctor but they only carry Lucas parts. What would you advise me?

1. replace with a Lucas distributor from Distributor Doctor?

2. get a spare set of twin Mallory points from Moss ?

The current set of points last since install, about 2000km so far.

Edited August 8, 2023 by earckens
clarification

[stuart]

13 minutes ago, earckens said:

I just checked: my distributor is a Mallory double points distributor. I called Distribution Doctor but they only carry Lucas parts. What would you advise me?

1. replace with a Lucas distributor from Distributor Doctor?

2. get a spare set of twin Mallory points from Moss ?

The current set of points last since install, about 2000km so far.

Mallory dizzys are good units so another set of points would be your best bet.

Stuart.

[Waldi]

The wear on cheaper points (often with a red plastic follower) is higher than on the good quality items with the brown “resin” followers (pertinax I think). I checked mine after 4500 km, and did not need to adjust dwell or timing.

Waldi