Timing, points gap etc.

[Willem]

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

[SHyslop]

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]

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]

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

[FrannyStephLux]

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

Have you previously adjusted the timing or points gap on this engine, or is this your first attempt?

[Willem]

This was my first time setting the points on anything. In the end I gave up on the dwell angle kit and just set it with feeler gauges and a timing gun, amazing how much you can change the running of the engine by paying close attention just listening to the engine sound and make small changes one at a time.
Still faffing with the reserve, it has some sort of cork "o" rings that work fine in the workshop but the moment they get soaked in fuel the reserve gets stuck and will not move, any one have a solution for this?

[David2021]

This comes under the "etc" part of this thread!
Why should a coil suddenly start overheating?
My 77 year old coil got very hot and didn't make much spark at the plugs causing a failure to proceed... A replacement modern one (non ballasted) was tie wrapped to it, connected up and sparks were restored. Then the same problem...after about 1-2hours running...not enough sparks from the now very hot (new) coil. Reconnect the old coil...away we go.
When I fitted the new coil the gap was checked, as was the timing and the car ran perfectly well, as it had been doing before the coil overheated.
It has been suggested that a too small gap on the points might cause it, but this was not the case, and -yes- the coils are connected properly!.
Any ideas?
David

[David2021]

Re the petrol reserve
Four Ashes Garage near Stratford remanufacture there units (mostly for Aston Martins) Gulp!
They are not easy people to deal with sometimes...I wanted the solenoid rewinding, but had to go the whole hog & have my unit rebuilt. I have yet to fit it, but hope it will work. They may be prepared to sell you the O rings, but tend to assume you know nothing and have a bottomless cheque book! Phone no 01789 266851. Speak to Jean if you can!
Otherwise look for petrol/ethanol proof O rings on the bay of E
Hope this helps
David

[SHyslop]

It's only the P2 cars that have the electric solenoid controlled reserve. The P1 has a manually controlled tap which has the two corks which are replaceable at home and which various sellers supply. I suspect that the originals, as with cork floats of the period, would originally be varnished with a petrol proof substance designed to prevent or limit the amount of petrol which actually seeped into them. In this way, the floats kept floating and the corks kept moving.

However, I suspect that this would prove a difficult thing to achieve now with modern petrol. What I have tried with reasonable success is to make new corks from a fine grain piece of bottle cork and turn this down to slightly undersize with some sandpaper or a file in the lathe and then give them a coating of JB Weld left to harden then smoothed down to fit.

[GOY189]

Hot coil = duff condenser in my experience!