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Re: Accuspark POSITIVE earth kit Installation

Posted: Fri Dec 16, 2022 6:09 pm
by Bill_qaz
svenedin wrote: Fri Dec 16, 2022 12:10 pm Thank you! I will test whether the earth is good or not with a meter and may have to redo this to Earth somewhere else.
Put your meter on volts dc and put the negative probe directly on battery earth, if you then put the other probe on an earth you want to check it should read zero if earth is good when the consumer is turned on. In your case the coil so ignition switch on.

Re: Accuspark POSITIVE earth kit Installation

Posted: Sun Dec 18, 2022 10:15 am
by svenedin
I have just measured this. There is continuity from the coil mounting bracket to the positive (earth) terminal of the battery.

Re: Accuspark POSITIVE earth kit Installation

Posted: Sun Dec 18, 2022 11:01 am
by geoberni
svenedin wrote: Sun Dec 18, 2022 10:15 am I have just measured this. There is continuity from the coil mounting bracket to the positive (earth) terminal of the battery.
But is there continuity from the end of that little cable to the battery post, which is what matters?
That does look like a nicely grey/silver painted surface you've connected to....

Re: Accuspark POSITIVE earth kit Installation

Posted: Sun Dec 18, 2022 11:30 am
by svenedin
Yes there’s continuity between the positive terminal of the coil to the coil mounting bracket via my new cable as tested with the new coil on the bench. I think there is no paint where the bolts that hold the coil bracket onto the dynamo go (the slot in the coil bracket). That’s where I put my probes.

Re: Accuspark POSITIVE earth kit Installation

Posted: Sun Dec 18, 2022 1:32 pm
by svenedin
All fitted. The car is running. Just having a lunch break and will then set the timing a bit better. I'll use the "by ear" approach that is well documented on here but I will check with a strobe that I haven’t done something crazy. I set the engine to top dead centre using the starting handle, the timing marks and lying under the car. Then I took a picture of the old distributor rotor pointing to lead number 1. I could then be sure everything was roughly correct with the new set up.

I found the tensioning bolt on the old coil bracket had no nut on the end so the coil was ready to fall off at any time. The O-ring on the old distributor shaft had been letting oil ooze out for a very long time.

The slot in the new coil bracket would not fit over the mounting studs so I had to file out the slots. At the same time I rubbed off the paint to ensure a good electrical connection to earth.


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Re: Accuspark POSITIVE earth kit Installation

Posted: Sun Dec 18, 2022 2:50 pm
by svenedin
I had a fiddle and got too cold out there. Initially the car wanted to kick back against the starter so I obviously didn't try to continue to start it. I assume the ignition was too far advanced and that caused the kickback. I set it by ear for best running and highest idle and then checked with a timing light. I was a bit surprised that at best idle the timing marks appeared more advanced than the furthest timing mark. However, the idle was a bit too fast (950) so I am assuming at that speed the centrifugal advance was operating in the distributor. I had disconnected and blocked the vacuum advance.

Tomorrow I could warm the car up, slow down the idle with the slow idle screw on the carb and recheck or I could just take the car out for a test drive. Obviously I don't want to damage anything. I could not hear pinking but I did of course nervously hear every little rattle!

I shut down the engine and tried a few re-starts as it is now and it started immediately with no kick back. It's probably absolutely fine.

Re: Accuspark POSITIVE earth kit Installation

Posted: Sun Dec 18, 2022 7:41 pm
by svenedin
I had some issues to get the new distributor to go fully home against the bracket. It would go almost all the way but not quite. It was not sufficient to just slacken off the pinch bolt. I also slackened off the front distributor bracket mounting bolt and the distributor went fully home with a reassuring clunk.

Re: Accuspark POSITIVE earth kit Installation

Posted: Mon Dec 19, 2022 8:54 am
by svenedin
Weather has warmed up so I will set the timing today and do a test run. I know the subject has been covered very extensively on the forum.

I am going to set the timing to 6 degrees BTDC dynamic at 600 rpm, vacuum disconnected and blocked. There will be two of us. I will go under the car with the strobe to read the timing marks and my assistant will move the distributor under my guidance. My strobe has a tachometer which is quite useful. I realise that the workshop figures were for different fuels and much younger engines but it seems like a good starting point. My concern is that when I set the timing entirely by ear it was really rather advanced, perhaps 15 degrees BTDC at 850 rpm, vacuum disconnected. That achieved the fastest idle and turning the distributor either way from that point gave a worse idle. I am not sure I know what pinking sounds like but too far advanced the engine sounded rattly and sickly so I assume that is pinking. Many years ago as a young man I think I do recall hearing engines pink especially when folk put lower octane, cheaper fuel in their cars than they had been set up to use. If set at 6 degrees BTDC the engine sounds bad I will of course adjust by ear. I am not fixated on the workshop figures, just using them as a start and a safety check. I have no intention of wrecking my engine! Once idling OK I'll go out for a test drive with the correct spanner for the pinch bolt in the glove box so that I can stop and adjust. There is a hill nearby that should be ideal.

Re: Accuspark POSITIVE earth kit Installation

Posted: Mon Dec 19, 2022 10:09 am
by myoldjalopy
Pinking is a metallic tinkling sound. Some have described it as dried peas rattling in a tin can. You will hear it when the engine is under load and will disappear if you ease off on the throttle, but return as soon as you try to accelerate again. Usually caused by over-advanced timing.

Re: Accuspark POSITIVE earth kit Installation

Posted: Mon Dec 19, 2022 1:52 pm
by svenedin
Thanks. With an assistant I have set it at roughly 6 degrees BTDC (probably more like 8 ) at 550 rpm, vacuum disconnected. I was amazed it would idle at such low rpm but it did very happily. Couldn't get exactly 600 rpm but wasn't going to be too pedantic about it. Car now starts and idles well. While I was under the bonnet I could smell petrol and noticed an ooze from the outlet union of the fuel pump. Not the hose, the join between outlet union and pump. Removed hose and tightened the union. Useful to notice.

Car idles very happily. Sounds better than it did with the old distributor (which had new points, distributor doctor condenser and red rotor but is an old worn distributor). Replaced vacuum advance hose and rubber connectors at the same time.

Road test next.

Re: Accuspark POSITIVE earth kit Installation

Posted: Tue Dec 20, 2022 10:12 am
by svenedin
Just road tested and seems fine. Very good in fact. Starts easily, pulls well, idle is even and healthy. So far, so good.

I should add that I am not necessarily going to keep electronic ignition. I did this because my original Lucas 25D 41269 distributor is old (1969), worn and needs an overhaul. I don’t have a spare so getting a new (albeit reproduction) distributor with the electronics already fitted seemed like a good thing to do for the time being. Distributor Doctor can overhaul my original distributor and then I will re-fit it to the car probably with points but maybe with an electronic module.

The most noticeable things from my test drive today is that the choke can go in sooner and the idle is very even. These things are most likely related to wear in my old distributor I think and not just the electronics….

I can't believe that the Accuspark distributors have the correct advance curves given the price of them. They also lack the little spring that makes the Advance/Retard micrometer adjustment move in clicks (11 clicks=1 degree).

Re: Accuspark POSITIVE earth kit Installation

Posted: Wed Dec 21, 2022 4:28 pm
by svenedin
Has anybody with an Accuspark 25D copy noticed that the micro adjuster wheel on the side of the distributor appears to do absolutely nothing? I had an assistant turn the wheel whilst I was under the car shining a strobe on the timing marks. I could see no change in the timing at all

Re: Accuspark POSITIVE earth kit Installation

Posted: Wed Jan 11, 2023 2:56 pm
by svenedin
My original Lucas 25D 461259 is on the way back from Distributor Doctor. It was very worn indeed and the overhaul was rather expensive but at least it will all be correct. Advance weights and cam were so worn out they had to be replaced.