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PostPosted: Fri Sep 29, 2017 12:08 pm 
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In most of the 4EFTE conversions the alternator is mounted partially into the drivers side wheel arch, which is reversed from the factory position so it runs in the opposite direction to factory. I know this does not affect the production of (AC) power however ventilation has to be considered.

Airflow through the alternator is from the back of the alternator to the front (pulley end), but does anyone know how effective the cooling of the rotor is when it's rotating in the opposite direction?

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I blame my dad for my love of minis. I think I was conceived in the back seat of one :D
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PostPosted: Fri Sep 29, 2017 12:17 pm 
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I've commonly read that reverse rotation only makes them about 75-80% as effective either in cooling or output, but lots of alternators ive dismantled had fans on them that dont seem like they'd be better moving air one way than the other.

Maybe find an alternator designed to rotate that direction if it concerns you?


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PostPosted: Fri Sep 29, 2017 12:34 pm 
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Harley wrote:
Maybe find an alternator designed to rotate that direction if it concerns you?

Thanks Harley. At ~75%, it doesn't concern me but if it was a figure less half the effective cooling than the standard rotation direction, then it may be an issue.

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I blame my dad for my love of minis. I think I was conceived in the back seat of one :D
I also blame my Dad for me being 6' 1" - not really the optimum height for driving a Mini.


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PostPosted: Sat Sep 30, 2017 12:35 am 
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Alan you should also consider that the "timing" of the contacts on the armature are clocked slightly to increase efficiency and output. Have you considered using a Honda alternator as they run the opposite direction?

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PostPosted: Mon Oct 02, 2017 12:48 pm 
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I've been considering the same thing. Most alternator blades are 'cupped' to grab the air and extract it out the side. It's not like a radiator fan where the air runs through the fan, the air hits the fan and is pushed out sideways.

With a radiator fan, if you spin it backwards, it will blow instead of sucking - this would cause the fan to change the air direction depending on the direction of rotation. With an alternator fan, it is always blowing out the side, so no matter which way it spins it still sucks air though the alternator, it doesn't blow if you change the direction. So by spinning it backwards, it works the same way, but since the fins are backwards it won't cup the air so much, and you'll lose some cooling efficiency.


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PostPosted: Mon Oct 02, 2017 1:30 pm 
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I phoned a local electrical rewinding company today and the guy I spoke to said all the car alternators he's seen with the internal fans (not alternators with the single fan next to the pulley) have a flat blade, or a very slight blade pitch so reversing is would have minimal effect in the ability moving the air outwards.

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I blame my dad for my love of minis. I think I was conceived in the back seat of one :D
I also blame my Dad for me being 6' 1" - not really the optimum height for driving a Mini.


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PostPosted: Mon Nov 06, 2017 10:46 pm 
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Guys,

I did my conversion 10 years ago and reverse mounted the alternator... It was from a swift because the stock Toyota one was too large.. never had an issue.. after about 30,000ks..


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PostPosted: Tue Nov 07, 2017 8:53 am 
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you've also gotta consider that the load on the alternator is a lot less than in a factory install - you're not running a lot of the electrical ancillaries like twin radiator fans, A/C fan etc.

the alternator fan should only be needed when the car is idling in traffic with the A/C going flat out - which is when the electrical system would be trying to draw the most current from it

If you're concerned, wait for a hot day and turn on your high beams, the A/C, radio, open the doors (interior lights) and turn on anything else that uses electricity in your daily driver and use a temperature gun to check the temperature of your alternator, then do the same with the mini with the alternator running backwards - I bet it doesn't come close

this may be a good read - https://www.electronics-cooling.com/200 ... ectronics/

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