Alternator upgrade

[Glenn]

There was an interesting thread recently which mentioned upgrading the Lucas ACR  alternator to an A127.  I think it has been lost with the crash.

Anyway, I took the advice and got a 55 amp A127 for a Montego.  I also got some 60 amp cable and was planning to wire the alternator straight to the battery. 

Problem is I've got HS6 carbs and the late engine mount spacers on the o/s.  I've also got a nice big Bosch 70Ah battery and the A127 is bigger than the ACR and doesn't fit.

I may have to recondition the ACR.  It's an 18 ACR which is 45 amps I think so it might be ok.  Failing that I wonder if I can remove one of the engine mount spacers to get more clearance - but will my airbox  fit the carbs then??

And it was all going so well - HELP!!!

[Richard B]

Hmmm Rock and Hard Place!  Move the battery to the boot? It always annoys me that the 2000 engine installation is not vertical owing to the Battery/Dynamo problem. You've got the best carb/inlet setup so you want to keep that, of course if you did move the battery you could improve the air intake......... :)

But I'll look out for one of the A127's thanks for the montego tip Rust Spot.

[Glenn]

Cheers Richard.  That's a very interesting thought - move the battery, mount engine vertically, perhaps leaving enough room for K&Ns on the HS6s.  Very interesting indeed...  I was also half thinking about LPG - run this on my Land Rover and it's great.  I think the PI engine would love 110 octane gas.  As it stands there is nowhere enough room on the air filter side of the carbs to fit LPG mixers - again moving the battery would solve this.  Why didn't I think of that?

I got the A127 for £10 on E**y, although the seller fleeced me for postage as they do (£14 but £7 of stamps on the parcel).  Still not bad I thought as it was NOS.  Part no. LRA 462, suits a few Rovers apparently.  It is handed incorrectly for the Triumph but it's a simple matter of undoing 3 nuts and turning the casing by 120 degrees.  Only thing is the ACR pulley and fan won't fit as the bolt is bigger so I'll have the hassle of tracking these down.

I'm just finishing my very prolonged resto so I think I'll just throw some brushes, a diode pack and a lick of paint at my 18 ACR to get me going.  However I'll be keeping the A127 as I know I will use it somehow!

[thescrapman]

Try this for the recon on the 18ACR.

Ebay item Item number: 120058521346

I bought a kit, seems like a good deal.

Cheers

Colin

p.s. you should easily be able to sell the A127, but having disclosed the price you paid, perhaps not much profit in it for you!

[Glenn]

Thanks Colin.  That's pretty cheap for all that kit.  I think I'll get myself one.

No, I'd never make a business man or a poker player - I give away too much!!  Might as well hang on to the A127 then.

All the best,
Glenn

[Glenn]

Well I got a recon kit from ebay and I can recommend dealing this vendor - no problems and very reasonable.

I got the alternator looking great - cleaned it up and spray painted it.  Unfortunately I made a right dog's breakfast of removing the rotor from the casing in order to replace the front bearing.  I put my puller on it but didn't like fact the claws were on alloy.  I didn't put much pressure on it because of this but it wasn't coming.  So I thought it would be better to hammer the rotor shaft out with the casing on wood held in a workmate.  I fitted the pulley nut to stop the shaft bruising and after some hefty taps it worked a treat.  Unfortunately when I removed the nut the thread came away.  The rotor is now scrap. 

A knowledge friend tells me (and I wish I had talked to him before wrecking my rotor) that bearings can last a lot longer than the other consumables and he only replaces them if they are noisey and rough.

I have a 17 ACR I can recon and fit instead but I rather liked the fact my 18 ACR had a bit more power.  What I wondered was could someone tell me which parts of the Lucas alternator determines its output current?  My friend tells me the rotor and stator are the same but the diode pack and regulator determine the output.

I'm confused as the rebuild kit is for 16, 17 and 18 ACR (34, 36 and 45 amp) the vendor is supplying the same rectifier and regulator for the range.  I'd like to know which parts to keep to maintain my 45 amp output.

Sorry for the long winded nature of this post.  Cheers, Glenn.

[Richard B]

I would have thought that it's the Rotor and the Stator (windings and magnets) that determine how much power is produced.

All the regulator pack does is rectify the power produced in the windings.

[Glenn]

Thanks Richard.  That makes sense - the bigger the magnets the more electrons they can potentially shift.

It would also explain why the recon pack is the same for the 16, 17 and 18 ACR.

[Glenn]

Finally got my 18 ACR rebuilt with the ebay purchased kit.

I used the rotor from a 17 ACR to replace the rotor I mashed up.  I couldn't find a code number on it but I would swear the 17 and 18 share the same rotor.  Ok - the windings could be different - but they look identical.  The stator is definately different - bigger on the 18.  The 17 also has a smaller regulator.

I couldn't find much info on the internet regarding replacing the bearnings.  The front one needed the puller but the rear one tapped off relatively easily with careful use of a chisel.

At the end of the day I would say I enjoyed the experience of rebuilding the alternator but it did take quite a few hours.  I would have to conclude the recon ones you can buy are very good value for money when you factor in the time spent.  Also having access to a bead blaster would give a better finish to the casing than the aluminium paint I sprayed on mine.

So I still have an A127, new old stock.  Presumably this will fit any other Triumph model that doesn't have battery/ alternator clearance issues.  So I had better look for something to use it on....  Hmm, TR5 maybe????

[thescrapman]

That's the way to do it.

Have an alternator, buy a car to fit it to.

Somebody started with a wheel and built a car round it, you can do it with an alternator.

Just don't spend ££££££'s on it....

:-)

Colin

[Glenn]

Unfortunately I will need to spend a few £££ to get my dream TR5!  Probably will stay a dream as £££ is what I lack!!!

Here's a snap of the 3 alternators with the A127 on the left.  You can see it's a bit shorter than the ACRs and a little bit wider (but not much and only a problem if you have a 2000 on HS6 carbs).  Also the pulley thread is bigger than the ACRs and I have shown an ACR pulley along with the A127 nut to show they are not compatible.

The 17 and 18 ACRs are exactly the same size.  The 18 was on my old Mini before getting bolted onto the 2500 engine.  I think it was originally off a Jag from the scrappy and was a bit of a dog having done a good few miles in its time.  Hopefully Ok now with new bearings, slip ring, brushes, diodes, regulator and hopefully giving a useful increase of about 9 amps to my charging capacity from standard.

I would be keen to track down a 20 ACR, just to see if it's the same size of casing.  That would give me the kind of output I was originally looking for.  I don't know anything about them other than they were fitted to TR7s with aircon, so I guess not very common in the UK.  Any advice greatly appreciated.  Cheers, Glenn.