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MG Midget and Sprite Technical - High output ALTERNATORS and STARTERS

The standard Lucas 16ACR alternator, as fitted to a 1500, produces a maximum of 34A (at 14V) at 6000 rpm. Is this enough for a 'modernised' car?

I have electronic ignition, halogen lights (which are always on - when the car is running), an alarm and separate immobiliser (I know...), a Kenlowe fan and 3" Revotec fan cooling the carbs (both controlled by a Revotec thermostatic switch) and probably some more stuff I've forgotten...

After a few short runs the (cheap standard recon) starter seems to struggle to start the car. But after (for example) a 100 miles at 70+ it's absolutely fine... The battery is in A1 condition (maintained using a CTEK charger) and so is compression etc.

A higher output alternator would seem to be in order. I've seen some 65A versions, but don't recognise the brands, and don't want to buy anything unreliable.

ANY RECOMMENDATIONS/ISSUES?

Similarly a more powerful starter might help. Again...

ANY RECOMMENDATIONS/ISSUES?

Thanks

Michael
readlist

Michael.
I have a 1500 running some extra elecrical loads too and my original alternator (16ACR) was struggling a bit. Then it failed in a big way so I upgraded to 18ACR (43A). They are dimensionally identical and a straight swap. I've had no problems since, even with short runs.

For replacement alternators try bad boy classics dot co uk ......they did the business for me and not expensive

I don't know about CTEK chargers. Is your car plugged into it when it's sitting in the garage? If so it should be okay if it's maintaining the battery voltage. How old is the battery?

If you're concerned about your starter a good first step is to open it up and give it a good clean. They get old and tired, but it's mostly because of dirt and carbon residue buildup. I've found brake cleaner spray effective.

Hope this helps. Cheers.
Greybeard

Micheal,
I've got an uprated alternator from MGOC Spares in May '08, the invoice shows "16/17 ACR 65A" I've used it since then with no problems. I've never checked the output as it easily keeps my battery topped up and runs the Revotec cooling fan which was connected directly to the battery so ran on after the ignition was turned off.

The alternator plug kit I got at the same time was low quality though.

I needed a new starter so added a Powerlite high-torque starter in September '08, I didn't really need a hi-torque but I prefer the zip-whizz sound to the old clatter sound and I really dislike cars that won't start so anything that gives them more chance of starting when things aren't perfect is for me, once the engine is running you stand more chance of limping home or finding or repairing many faults. Again I've had no problems and like the extra margin the hi-torque gives in turning the engine over and saving a bit of battery.

Bad Boy Classics sell uprated alternators and they seem to be OK but I have no direct knowledge to confirm this.

ETA - This post was typed as Greybeard posted so independent mentions of BB Classics.
Nigel Atkins

I still love my high torque starter...its the iszuz

i got it from

www.britishstarters.com

Prop
Prop and the Blackhole Midget

Hi Michael,


It's never a bad idea to have a higher output alternator, especially on a car like yours with lots of extra electrical stuff.


Years ago I uprated to 1500 to the later Lucas A127 type unit, think it was for a Rover 800, it's rated at 75amps.



Never had a problem with flat batteries and the volt meter shows a healthy 14v with everything running.



Had no experience of uprated startes, the standard one works fine with a decent battery and a good engine earth.


Regards Steve.
SR Smith 1

Thanks guys. Very helpful and much appreciated.

Re. Greybeard's question, the battery is in v.good condition (I had it tested recently) despite being over 4 years old, largely down to the CTEK maintenance charger to which it is permanently plugged (when in the garage) I would imagine.

I was tempted to change the starter first, but now I think I'll switch to a higher output alternator and see what effect that has.

Thanks again

Michael
readlist

Surely 34 amp is plenty? Two 60 watt headlamp bulbs are only going to use about 10 amps. Side and tail lights an amp or two more. The electronic igntion would use very little power. Of course the old alternator might not be working efficiently, but I would go for the high torque starter. I had one on my Lotus Elan and it was like night and day when it came to turning the key. Not only did it whizz the engine over enthusiastically, but it was pre-engaged so it wasn't hammering the ring gear with that awful Bendix gear. Mine was a Wosp brand and I loved it. (Past tense because I have recently sold the Elan).
Mike Howlett

Mike, I've been mulling this over during the day. It's starting the engine that drains the battery and then the alternator struggles top it up, unless on a long fast run - all the extra electrical stuff slowing the recharge still further.

So maybe the starter first then...

WOSP, POWERLITE or another brand??
readlist

Michael,
Whether an old starter or a new fast spin one, the engine should start within 2 - 3 revolutions anyway. If you have to go on grinding away on the starter, flattening the battery, then there's summat wrong with the engine set up.

The only exception is if you have a mechanical fuel pump and the carbs have drained down (choke left open maybe?)or evaporated dry. In which case the engine is just a heavy duty fuel pump motor for the first 10 turns or so!

That said, a fast spin one is certainly nicer and it will at least feel as if it is starting more readily!
Guyw

I am struggling to recognise these symptoms.

My car has halogen lights, electric fan, electronic ignition, radio etc
It has a 6 year old battery with a normal alternator and normal starter.
No charger fitted ever
And it has no trouble starting my high compression 1380 every time under all circumstances even after 2 months of not using it.

Check your ignition timing and fuelling at startup the answer might be simpler (and cheaper) than you think.

but they do sound cool those fancy starters
Onno K

I like your thinking Onno. But if the timing or fuelling were off so much I imagine they would affect normal running too. Maybe. What do you think?

When it happened to me the clue about the alternator being unwell was the condition of the belt which was fairly new. It had gone very shiny on the working surfaces and there were lots of cracks, so I surmised it had been struggling for a while before it collapsed completely. The real reason I got an 43A upgrade was it was the same price as the 34A original.

But I agree that a 16ACR in good condition should be able to cope. Rebuild kits for them are inexpensive and it's not a hard job if you can get someone with a chatter-gun to whizz the pulley nut off and on for you.

I still have the original type starter which works fine, but I do like the idea of a pre-engaged unit as Mike says. Bloody bendix gears!

Good luck.
Greybeard

This thread was discussed between 22/08/2016 and 26/08/2016

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