Alternator - 45amp or 80amp?

[gordonlund]

Hi,

As Brian wrote, the bottom alternator bracket off any Ford Kent (OHV) engine will fit. Cortinas and Escorts are a bit hard to find now but some early Fiestas had Kent engines fitted. As for the top bracket, take a standard bracket and put a 1/8" kink in it in the vice at the appropriate point. Lotus bracket was forked to go either side of the timing chest, if you can find one.

Gordon

[handi_andi]

Hi all
I have been thinking about this ever since I saw Ratsport were doing 45amp and 80amp alternators, but then thanks to a post on here starting having a deeper think given that the wiring loom is sized for 35amp alternator.

A 35amp alternator running at 12v will produce 420watts of power, however, most of the time they are running at around 14v giving 490watts

Thinking about the static loads we are tyically putting on the system at night and we have:

Headlights: 2 x 55watts = 110watts
Driving lights: 2 x 55watts = 110watts
Sidelights and rear lights: 2 x 21watts + 4 x 6 watts = 66 watts
Panel lights: 8 x 3watt= 24watts
Coil: say 50watts?
Heater fan or cooling fan (chances of both being on not too great) = 100watts?
Charge to battery: 10watts?

Total: 470watts

So a 35amp alternator should be sufficient for most applications. Yes the load goes up when indicators are used and brake lights, however, any extra power can be drawn from battery then subsequently replaced. Hence is there any real need for an extra 10amps of charging current, i.e. 120 to 140watts, what is it really going to be used for? Admitedly if you drove around with headlights, driving lights and fog lights on it might be useful, however, I have never seen my voltmeter drop out of the green zone even with everything turned on personally.

Andy

[ncm]

Hi Richard, The bracket you require looks like the smaller of the two shown in the attached photos.You do NOT require the larger one as it fouls on the adjusting strap bolt as I found out when recently converting my +2 As Gordon said above the genuine adjusting strap fits around the front covers and is quite easy to fabricate if you have access to welding tackle. You should also be able to make out what Lotus referred to as a mounting strap (050E6004)which was also fitted.This is even easier to fabricate as it is nothing more than a piece of thin steel sheet with three holes in it! I presume the intention of this part was to act as a brace to support the front cover lug that the adjusting strap pivot bolt runs through.

Cheers, Brian.

[RichardS]

You do NOT require the larger one as it fouls on the adjusting strap bolt as I found out when recently converting my +2

Cheers, Brian.

Thanks for all the further advice. Brian - there is an alternator bracket on Ebay at the moment similar to the bigger one in your picture - I took my dynamo off today and thought the bigger one looked a bit, well, big! Thanks for confirming this. I have found a Ford bracket so will use this.

Richard

[TimButDim]

Sorry for joining the thread late but I was wondering if there's any way of telling which alternator I have without taking it off? I've just had an operation on my arm and I'm not quite up to getting the tools out yet!

The alternator packed up on the way from collecting it and I'm assuming a 45 amp would be ideal (my wiring is described as original, at best!), but I wanted to make sure that it would be a straight swap for what I have now (picture attached), I'm assuming the current item is an alternator as the dynamo pictures I've seen look very different.

Thanks!

Tim

Luke motorsport have some good looking alternators - I want to replace the original dynamo on my 1973 Sprint. http://lukemotorsport.co.uk/lukemotorsportua.html

They seem very reasonably priced - ?28 for the 45amp and ?36 for the 80amp [they also do a gear reduction starter for ?105 which is a lot cheaper than some of the suppliers].

My question is 45amp or 80amp? Is it the more ampage the better or will my wiring melt!!

Richard

[bcmc33]

Tim,

It looks like an LMA100 (45amp). Order one from Luke and you will not be disappointed.

BTW you need a RH fitting.

[TimButDim]

BTW you need a RH fitting.

Will I need to specify a RH (right hand?) fitting when I order, or is this a separate item?

Thanks!

[bcmc33]

They are made either RH or LH fitting. Just ask for a RH unit.

[neilsjuke]

Alternators are self regulating so 45amps for a elan will be fine .
Neil

[RichardS]

Tim

Spotted the rejuvenation of my old post!. I fitted the 45 amp alternator from Luke - haven't actually had the engine running yet but it looks nice and shiney in the engine bay. I managed to get the brackets from Sue Miller [I think I got the last one she had] and it all fitted fine. The rewiring from a generator is pretty straightforward - I think there is an article in this site which explains the changes neeeded.

Richard