Conversion to Dynamotor alternator

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This topic contains 8 replies, has 5 voices, and was last updated by  Cameron 7 months, 3 weeks ago.

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  • #594

    Cameron
    Participant

    I am considering moving to the Dynamotor – alternato that looks like the original dynamo. I am confused about the pulley required. I have read that the alternator needs to rotate more quickly ( requiring a smaller Pulley ) – has anyone got experience in size of pulley and source to purchase and whether a fan is required. My vehicle was changed to alternator some years ago – would the pulley & fan off that be useable on the dynamotor ?.
    I did try the manufacturer with no real feedback.

    Thanks in anticipation.

    Cameron

    #597

    Flinty
    Participant

    Hi Cameron.
    I fitted a Dynamotor to my Dart a few weeks ago and I used the existing pulley off the Dynamo.
    The only problem I had was that the ignition warning light terminal comes out of the Dynamotor on the side rather than the end and it is exactly where the oil filler tube is located. To overcome this I had to use a slightly longer fan belt and to be safe I put a plastic sleeve around the oil filler in case it ever came into contact with the terminal.
    It works perfectly charging at very low revs.

    Steve.

    #596

    ozzsp250
    Participant

    I have done that change to an SP250 and did change to a smaller diameter puller which I purchased out of the UK – links below. I did use them on the Dynamator which I purchased local in USA. So far only run on my engine in the test stand but functions very well.

    https://www.holden.co.uk/displayproduct.asp?sg=1&pgCode=080&sgName=Electrical&pgName=Dynamos+%26+Starters&agCode=1551&agName=Dynalites&pCode=081.218

    and

    https://www.holden.co.uk/displayproduct.asp?pCode=081.217

    #614

    lauriej1s
    Participant

    It is possible to re-position the side terminal on the casing of the dynamotor to the rear as per the old style dynamo – saves cutting/re-shaping the aluminium cover. There is plenty of electrical lead inside to achieve this and it’s not a hard job whatsoever.

    Laurence

    #617

    Cameron
    Participant

    Hi
    Thanks to all for replies – things are a lot clearer now I will think on it & decide what to do.

    Rgds !
    Cameron

    #619

    Dave W
    Participant

    I have tried both the Dynamator and the Powerlite and both have failed. The latter over volting and burning out the electronic ignition module. On returning to Eurolec I was told no fault had been found but an updated rotor had been fitted. Both failed in the summer heat of France during 1000 mile trips. I carry the Dynamo regulator and points in the boot so it was not a great problem. I wonder if excessive heat affects the electronic regulators. Because of the steering rack the crankshaft fan has been replaced with a Kenlowe in front of the rad. I believe Robert Grinter has had problems with these but has found one that has proved to be reliable. For now I am sticking with the Dynamo and a separate electronic regulator unit from Classic Dynamo and Regulator Conversions, which is built into the original case.
    Dave W

    #633

    ozzsp250
    Participant

    After I fitted my electronic ignition to engine while on test stand initial results were very good, test stand is set as negative ground as was electronic module. After the next update to new plug leads with ‘built-in’ extenders moulded to fit directly to the spark plugs the electronic module failed . In communication with UK suppliers of electronic module they stated the plug wires were not suitable. I purchased a new module and used other plug wire set as all runs fine. I have a complete spare distributor with dual points , rotor , cap and the moulded plug leads that takes about 10 minutes to convert back as wiring between coil and distributor is different. Engine runs similar on test stand with either set up — long term road test will tell durability.

    I do have a a Dynamator on the engine which functions very well so far again long term road test will tell durability.

    #686

    ozzsp250
    Participant

    Update to my Dynamator conversion on the engine still in test stand, I run the engine a couple of days ago and the Dynamator had no output. I have set up the system to drive the voltage to the field via relay with a fuse inline. The 10 amp fuse was blown so I disassembled the Dynamator and found the electrical leads from the commutator to field coil both failed at the solder joint. It is potentially poor quality control which is disappointing for sure.

    I have repaired the wiring and re-installed the Dynamator, will run the engine again in the next couple of days, then report the results.

    #740

    ozzsp250
    Participant

    After reinstalling the repaired Dynamator, it failed to control the voltage and was charging at 16 volts. As I did not want to fail the electronic ignition I elected to purchase another Dynamator. As I needed to remove the end of new unit to reverse the 12 volt supply terminal hardware for clearance I checked the internals of the unit. I must say it is assembled much better than the first and uses different components. I then installed it on the engine in the test stand and found it to function correctly charging at 14.4 vdc.

    As luck would have it while running the engine the water pump elected to fail its seal……so the saga of getting engine ready for the car continues.

    #780

    ozzsp250
    Participant

    Follow up I came across this on another forum from another Dart owner.

    I’ve had a dynamator fitted to the Dart, apart from needing to turn the alternator within the casing to avoid fouling the oil filler (Dart specific), it works well. One point tho’, you need a smaller pulley on it to make the alternator run at a higher speed.

    Apparently they have Bosch innards with a Chinese casing:-

    The author followed up with this comment.

    No it doesn’t work well, it’s just burnt out my Pertronix electronic ignition, apparently the power they put out has horrible spikes, due to being a Chinese copy and cheap.

    Martin, the Distributor Doctor diagnoses an auto electrician and a couple of extra diodes, but knows this well.

    Link: https://www.pistonheads.com/gassing/topic.asp?h=0&f=140&t=1489818

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