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Alternator Spec
Posted: Sun Sep 17, 2023 5:17 pm
by Peted7202
I have an Magneti Marelli alternator rated at 85amp. Could this be used on the Minor?
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Re: Alternator Spec
Posted: Sun Sep 17, 2023 5:27 pm
by Bill_qaz
From the pictures it would need a pulley change to v belt and check alignment on installation. The W terminal for the warning light looks to be missing. Far simpler to just buy a suitable alternator for circa £50 that's a direct fit.(same as mini) 18ACR 45 Amp plenty enough output for a minor.
But your decision

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Re: Alternator Spec
Posted: Sun Sep 17, 2023 6:38 pm
by svenedin
Or even simpler, stay with a dynamo
Re: Alternator Spec
Posted: Sun Sep 17, 2023 7:15 pm
by philthehill
The alternator under discussion is of the type fitted to the MPI classic Mini.
I would suggest that a single 'V' belt would not efficiently drive the Marelli alternator. The resistance to turning will be quite high thus the need for a multi 'V' poly drive belt.
You would at least need the multi groove crankshaft and water pump pulleys or toothed drive belt set up and mount brackets.
Even a Lucas lower output alternator is prone to belt slip and squeal when asked to produce power especially after a engine start.
https://www.scparts.co.uk/sc_en/british ... relli.html
https://www.scparts.co.uk/sc_en/british ... on.html#49
https://www.scparts.co.uk/sc_en/british ... ys.html#22
To be honest a lot of trouble and expense for little gain over a Lucas 18ACR alternator.
Re: Alternator Spec
Posted: Sun Sep 17, 2023 7:42 pm
by Peted7202
Thank you.
Re: Alternator Spec
Posted: Sun Sep 17, 2023 8:55 pm
by Bill_qaz
To be honest a lot of trouble and expense for little gain over a Lucas 18ACR alternator
Totally agree Phil

Re: Alternator Spec
Posted: Sun Sep 17, 2023 8:57 pm
by Bill_qaz
svenedin wrote: ↑Sun Sep 17, 2023 6:38 pm
Or even simpler, stay with a dynamo
How do you know he is replacing a dynamo?
Re: Alternator Spec
Posted: Sun Sep 17, 2023 9:29 pm
by oliver90owner
PTH is right on the money re driving that alternator. A single narrow section V belt would soon be shredded if attempting to generate a kW. Automotive alternators are not the most efficient, so the single belt would need to transmit around 1 1/2kW - that is without the water pump and fan. Especially as that potential 1kW could be generated at a low belt speed!