Joined: Jan 2019 Posts: 48 Threads: 9
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had the same problem, more noticeable on the cam gear then the dizzy gear, (due to the iron cam gear wearing rapidly in relation to the new steel gear on the dynamator) cam gear totally buggered and copious debris in the sump.
Clearly Accuspark tech department have not been able to replicate the exact geometry of the original A7 gears.
If they made a new steel cam gear to fit the geometry of their dynamo gear - that might be a solution
although i suspect it then wouldn't mesh correctly with the crank gear...
Joined: Sep 2018 Posts: 134 Threads: 17
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Location: Oop North
We fitted a Dynamator to one of our cars and used the original gears on both ends. This has proved to be reliable. There is clearly something amiss with the Acuspark gears.
Joined: Sep 2019 Posts: 5 Threads: 0
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Location: Bristol UK
Car type: 1931 Box Saloon
Thanks for that--------------I have been able to contact the previous owner of my car who was able to tell me that it has got "old A7 " gears driving it.
BUT
How about the blown bulbs problem?
Can a voltage regulator be fitted or can the wiring be revised to stop the problem?
Joined: Sep 2018 Posts: 134 Threads: 17
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Location: Oop North
I'm sorry, I can't help on this one, I didn't experience any bulb blowing issues.
Joined: Sep 2019 Posts: 5 Threads: 0
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Location: Bristol UK
Car type: 1931 Box Saloon
I'm still scratching my head!
Joined: Aug 2017 Posts: 65 Threads: 11
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The electronics are all built into the unit. Apart from the gear issue I had two fail electrically. The second one did about 50 miles before failing. Cheap Chinese components in my opinion. As for the gears they were totally the wrong tooth form. Skew gears need a bit more skill than straight cut gears but the sellers refuted any claim that the gears were wrong. Compare the price of the dynamater to the price of a properly converted dynamo. That will suggest why they tend not to last.
Joined: Aug 2017 Posts: 254 Threads: 3
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Location: Shropshire, UK
07-10-2020, 07:00 PM
(This post was last modified: 07-10-2020, 07:01 PM by Ian McGowan.)
Blowing bulbs is invariably a consequence of excess voltage being applied to them. The lead acid battery, with its exceedingly low internal resistance acts as a "sink" to stabilise the output from the dynamo. A usual cause of bulbs blowing is a situation where the battery becomes disconnected from the circuit thus allowing the voltage to rise to well above normal. Operating a battery isolator switch with the engine running can be a cause.
Joined: Sep 2019 Posts: 5 Threads: 0
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Location: Bristol UK
Car type: 1931 Box Saloon
There's a good thought.
I wonder (in my ignorance) if the battery master switch is involved!
Any knowledgeable further thoughts would be gratefully received!
Joined: Feb 2022 Posts: 1 Threads: 0
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Location: Cornwall
Car type: Austin 7 RN 1932
Interested in this thread. I had endless trouble with the cut out and then dynamo on my '32 RN so bought a dynamotor stupidly ordering + earth instead of negative earth so had to convert the car electrics. The unit failed after a few hundred miles and the supplier sent me a negative earth unit without charge even though it was well over a year since purchase. This unit then failed a few hundred miles later, bringing the car to a dead halt on a fast road by fusing out the supply to the coil. So I purchased a cut out for £45 and a dynamo at the Moreton show for £75 which predictably didn't work. However the all knowing Andrew Jarmin (Cornwall A7 Club) breathed his magic on it and bingo I have sparks again. Sadly fitting it revealed that the dynamo drive gear and camshaft drive gear are b*ggered adn worn away now so that's another problem to fix. I see the Dynamotor is off the market now, fortunately. Also fitted LED lights bought at the show and the brilliance of the brake and indicator lights is a revelation. A major safety improvement.
