Timing, points gap etc.

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Willem
Posts: 40
Joined: Wed Jun 30, 2021 11:32 am

Timing, points gap etc.

Post by Willem » Sun Feb 04, 2024 1:37 pm

Good afternoon all,
I have just started increasing my knowledge of my P1 12 tourer again, clean tank, fit fuel filter, clean carb and such.
I have recently acquired a multi meter that also incorporates a dwell meter, now as far as I can find out the dwell angle on a 4 cyl. tourer should be 45degrees, plus or minus 4, (max gap 0.015) having run the engine it shows as 89.4 degrees (0.018), not quite what I was expecting. I have never changed the points gap since I acquired Mathilda, the engine runs quite smoot at all revs, but I do feel that the engine is not as powerful as I would expect, she does run a bit rich, no matter how I fiddle with the mixture setting and when coming off the throttle she sometimes "pops".
Having never worked with this age of engine, would it be worth setting the points gap to 45 degrees and check the timing, I am a bit hesitant as at the moment she is running but changing too many variables might well get me down a rabbit hole I would regret.
The bit I am struggling with is that to reduce the dwell angle, the points gap needs to be increased but the measurements of the feeler gauges suggests the opposite..

Any advice is appreciated

Will
Rover 12 Tourer, 1936
Range rover L322, 2009

SHyslop
Posts: 49
Joined: Thu Dec 30, 2021 4:17 pm

Re: Timing, points gap etc.

Post by SHyslop » Mon Feb 05, 2024 10:30 am

Something I have encountered from time to time is that if the contact set is of recent manufacture, it can be that the fibre heel that is moved by the distributor cam can be fractionally too long. This prevents the points from shutting completely yet they can be set with the correct open gap, but not provide very good running. Connect both leads from the meter to the two sides of the points and check for continuity when the points should be shut.

The answer is to either change the points to a better fitting set or file a bit off the heel until the proper dimensions are restored. This may have nothing to do with what you are experiencing but I thought it worth mentioning as a problem which is of modern making rather than showing up in older books when parts were of a better standard.

Personally, I haven't found a dwell setting much use on the pre war car but a suitably small precise gap of 12 thou usually works.

GOY189
Posts: 554
Joined: Sun Oct 19, 2008 5:08 pm

Re: Timing, points gap etc.

Post by GOY189 » Tue Feb 06, 2024 11:19 am

Are there ranges on the dwell meter for 4,6 and 8 cylinders? if so switch to 4 cylinders and re test. May be obvious but what do the instructions say?
It could be that your meter is specific to an 8 cylinder vehicle.

Mike

Willem
Posts: 40
Joined: Wed Jun 30, 2021 11:32 am

Re: Timing, points gap etc.

Post by Willem » Mon Feb 19, 2024 1:30 pm

Thank you both for the replies,
I have filed the points flat, set the timing, set the gap to 12thou., set the mixture and fitted an inline fuel filter, now running beautifully. However the float in the tank will need a bit of encouragement to get moving and the mileometer has stopped working.
One day I will have nothing to do to her, but not yet..

The dwell meter has multiple settings, 4, 6 and 8cyl., I am not sure it is working correctly, will need to investigate.

Will
Rover 12 Tourer, 1936
Range rover L322, 2009

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