Alternator conversions: did you have to trim your mount bush

[TBG]

"I think it a myth that the alternator drive belt shortens the life of the waterpump."

Not in my experience, Ian.

I used to have water pumps fail regularly, since this mod not one in well over 100k miles.

[alan.barker]

The 100K is proof
Alan

[Elanman99]

I too have had several water pump changes in the life of my car, mostly they were in the first 10 years of ownership. The last waterpump rebuild was about two years ago when the pump I fitted in the 1989 (when I also fitted an alternator) finally failed.

I am aware that pump damage can be caused by excessive belt tension.and I run with the belt distinctly slack but the ACR17 alternator copes without problems (I don't have heated seats, air con, fog lights or anything else that might impose a high electrical load.

Ian

PS I think 22 years is proof too!

[alan.barker]

Well for sure it sounds like we all know how to tension a Fan Belt not too much.
It also seems best not to have an Alternator which pushes out too much power to overload the wiring. Enough Elans have gone up in smoke.
You don't get something for nothing.
If you fit an Alternator that pushes out 60 Amps it takes more friction on the Pulley to turn it = tighter Fan Belt= Water Pump Bearing overloaded.
Alan

[TBG]

Ian you have a good point!

When I first fitted an ACR jobby I found that especially when really wet the alternator slipped with a terrible scream. Thus I had to tighten the belt a bit more and poof the water pump fell off it's perch! My twin pulley gets around that problem - tight as you like and a smiling water pump.

[alan.barker]

I now use the Fan Belt with notches on the inside dia. They are more flexible than the smooth ones and more grippy . Don't need a lot of tension
Alan

[TBG]

So do I. I once tried toothed belts with all the associated pulleys but they kept shattering! Those in the know(?) said it was some harmonic that was doing the damage. Possible I suppose but I binned it toot sweet.

[Andy8421]

+1
Imho the ACR17 is rated correct and that's why Lotus fitted it to later +2 Elans.
Alan

Alan,

I don't want to seem to be picking up on your points, but I am not sure this is correct. The original C40L Lucas dynamo was rated with a maximum output of 25 amps. The 17ACR is rated at 36 amps.

The only time the 17ACR would be producing 36 amps on the Elan would be at high revs into a flat battery with all the electrics on, but in principle, it could happen. The original wiring from the dynamo to control box, and then on to the battery on earlier cars went via a dash mounted ammeter, and was (IMHO) marginal at best. Fitting a 17ACR to this setup is asking for trouble. I believe the later cars had a battery voltage meter dispensing with the extra loop of cable.

Were it me fitting any alternator to an Elan, I would dispense with the original connections to the dynamo and control box and run a new, suitably sized cable direct from the alternator to the battery side connection on the starter relay. If I really wanted to keep the ammeter, then replacing the ammeter loop with a thicker cable is probably a good idea.

This doesn't detract from your point that you can't just put any old alternator on an Elan and not consider that wiring implications - which I agree with, but even a humble 17ACR needs some thought before fitting.

[alan.barker]

Hi Andy,
You're right. For sure you remove the Ampmeter on a +2. None on an Elan.
For the charging the Alternator will charge more than Dynamo at low revs so the Indicaters will function.
On a +2 you fit a Volt meter as Lotus did.
On my Sprint with Dynamo i need to keep revs high so Indicaters function. A pain in the butt to be honest.
Alan

[Bud English]

Even if you install a fifty or one hundred amp alternator, the only circuit that is impacted is the one between the alternator and the battery. All the other wiring will only see the current that is drawn by the components on that circuit. The alternator will not push higher currents into any circuits. It will make higher currents available to those circuits if they malfunction and draw more, but proper sized fuses in those circuits will prevent that from happening.

Taking the ammeter, control box, and associated kindling, out of that unfused charge circuit and replacing it with a voltmeter is the prudent and safe thing to do, unless, of course, you can find a shunt style ammeter with a Smiths instrument face.