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ALTERNATOR UPGRADE FOR 1850H AND UNKNOWN ALOYS
Posted: Sun Oct 25, 2009 8:30 pm
by scotchydoodle
Hi folks, first post. just bought an 1850hl last week, had a few triumphs in the past (tr6,1300tc) but this is my first dolomite that is actually usable. I've just fitted a set of halogen headlamps and what with winter coming in I noticed that the alternator is struggling to cope with headlamps, blower etc. Is there a common alternator upgade? Also, my car is fitted with a set of wheels (picture below) which I've never seen before. The gent I bought the car from tells me they are cosmics and were fitted by the triumph dealer when the car was new but I'm not sure.
any help would be much appreciated.
Thanks, Paul.

- dolly 001.jpg (53.06 KiB) Viewed 4403 times
Re: ALTERNATOR UPGRADE FOR 1850H AND UNKNOWN ALOYS
Posted: Sun Oct 25, 2009 9:20 pm
by triple tango
Rover 100 alternator is a direct replacement, nearly double the power output & takes up less space too.
Re: ALTERNATOR UPGRADE FOR 1850H AND UNKNOWN ALOYS
Posted: Mon Oct 26, 2009 12:28 am
by Phil_G
triplecustard wrote:Rover 100 alternator is a direct replacement, nearly double the power output & takes up less space too.
Hi,
Does that advice stand for the 1500 as well?
Cheers
Phil
Re: ALTERNATOR UPGRADE FOR 1850H AND UNKNOWN ALOYS
Posted: Mon Oct 26, 2009 11:31 am
by JPB
It stands for pretty much any ACR series application, Phil. There are such as Delco alternators that are yet more efficient and smaller, but the later Lucas body style will bolt straight on and mate to the connector if your car has the single "Euro" plug and machine sensing.
If the 1500 is still on battery sensing charging, you'll see two separate plugs going into the back of the alternator, this isn't a problem as you can change to the Euro style and modify the wiring to suit.
If you fancy an upgraded alternator that looks exactly the same as the original ACR16, I have two left here which are 50A machines, that amount of current is still just about ok with the existing wiring, anything more and you ought to be considering an additional cable (from pin 2) that goes straight to the battery, matching the area of the one that's attached to the stud on the solenoid.
Re: ALTERNATOR UPGRADE FOR 1850H AND UNKNOWN ALOYS
Posted: Mon Oct 26, 2009 7:24 pm
by scotchydoodle
THANKS FOR THAT GUYS. ANY PARTICUAR ROVER 100 MODEL OR ARE THEY ALL THE SAME? WILL METRO ONES ALSO FIT?
Paul.
Re: ALTERNATOR UPGRADE FOR 1850H AND UNKNOWN ALOYS
Posted: Mon Oct 26, 2009 9:23 pm
by JPB
miniMetro ones have ACR bodies while 1984ish, then A127 bodies, which are shorter but not really any slimmer than the original. They definitely have single, 3-pin Euro plug fitting and the lugs are in all the right places. Either an ACR (miniMetro) or (A127) from the later K-series (Rover Metro/100 series cars) will bolt straight on and plug in. Fitting to an 1850, you will need to transfer the thicker spacer from under the fan or the pulleys won't line up, that spacer isn't found on most other applications.
The old-style ACR (Part Number LRA100) is easiest to keep going as parts are available and they were much the same from 1975 through 1998. Diode pack, stator, regulator and bearings usually only cost around £20 for the older machine and it's an easy, DIY job to sort their common failings or to overhaul everything, that's what I'd do for a Dolomite 1850 alternator given that the radiator has to come out and I don't want to be in there too often.
Re: ALTERNATOR UPGRADE FOR 1850H AND UNKNOWN ALOYS
Posted: Tue Oct 27, 2009 8:44 am
by Nick C
JPB wrote:...that's what I'd do for a Dolomite 1850 alternator given that the radiator has to come out and I don't want to be in there too often.
IIRC The rad doesn't have to come out if the bolt was put in the right way round when it was last assembled...
Re: ALTERNATOR UPGRADE FOR 1850H AND UNKNOWN ALOYS
Posted: Tue Oct 27, 2009 12:43 pm
by JPB
Nick C wrote:JPB wrote:...that's what I'd do for a Dolomite 1850 alternator given that the radiator has to come out and I don't want to be in there too often.
IIRC The rad doesn't have to come out if the bolt was put in the right way round when it was last assembled...
With a 6-vane water pump cover, the bolt would
only go in from the front, so the rad has to come out. Later, 12-vane covers do indeed offer sufficient clearance as the bolt would be fitted from behind, but that's a minority of cars.

Yes, you could put the pivot in from behind and fit the alternator
before mounting the water pump cover, but I'd rather open the radiator and drain the system that way than introduce the risk of compromising a top cover that's been fitted correctly and doesn't leak.
Re: ALTERNATOR UPGRADE FOR 1850H AND UNKNOWN ALOYS
Posted: Tue Oct 27, 2009 6:58 pm
by Triumph1300
Yep, they're Cosmic alloys, are there any spacers behind them, or are they bolted directly upto the hub?
Re: ALTERNATOR UPGRADE FOR 1850H AND UNKNOWN ALOYS
Posted: Tue Nov 10, 2009 10:42 am
by Jon Tilson
I'll agree withe everyting JPB says about this except the likelihood of finding a later 6V cover or 12V cover both of which will allow the bolt to come out backwards.
I dont have any proof but I reckon the change comes in from late 74 on...so you are more likely to find the easy rearwards method.
With halogen lights you DO need a relay to stop the higher current burning out your dip switch contacts, whih WILL happen leaving you lightless and with an expensive repair if you dont.
A127 or LRA 100 is the way to go.
Jonners
Re: ALTERNATOR UPGRADE FOR 1850H AND UNKNOWN ALOYS
Posted: Fri Dec 04, 2009 8:28 pm
by jeroensprint
Jon Tilson wrote:I'll agree withe everyting JPB says about this except the likelihood of finding a later 6V cover or 12V cover both of which will allow the bolt to come out backwards.
I dont have any proof but I reckon the change comes in from late 74 on...so you are more likely to find the easy rearwards method.
Jonners
The mountingholes in the covers are a bit bigger than the bolts. When having the cover on with the bolts in but not tight yet, you can turn the cover a bit within the play of the holes. Make sure before tightening the cover sits on the right place to have the alternator bolt to go from the rear.
Jeroen
Aha............
Posted: Fri Dec 04, 2009 8:51 pm
by sprint95m
Jon Tilson wrote:I'll agree withe everyting JPB says about this except the likelihood of finding a later 6V cover or 12V cover both of which will allow the bolt to come out backwards.
I dont have any proof but I reckon the change comes in from late 74 on...so you are more likely to find the easy rearwards method.
There are two types of six vane impellor, Jon.
Did each of these have its own cover? If so, that could explain the change you reckon occurred c. late '74?
Mine is the early type like John's, so I had to remove the radiator to replace the alternator
.
Incidentally my car came with a 15ACR, but after altering the wiring I fitted a 17ACR alternator.
Re: Aha............
Posted: Fri Dec 04, 2009 9:00 pm
by JPB
sprint95m wrote:Mine is the early type like John's, so I had to remove the radiator to replace the alternator

.
Incidentally my car came with a 15ACR, but after altering the wiring I fitted a 17ACR alternator.
I did the same to the wiring on mine, the original alternator was a game little thing, and did its best, but for a daily driven car and as one who has used cars with generators as dailies too, the lure of a bigger machine, that allows me to sit in traffic with the HRW, dipped heads, blower and wipers all running
and the voltmeter still showing a charge, was just too great to ignore.
ISTR that I did once post asking whether the regulator and diode pack for the older, battery-sensing device were available, but as the mod can be made invisibly, a bigger alternator was the better solution.
Re: ALTERNATOR UPGRADE FOR 1850H AND UNKNOWN ALOYS
Posted: Thu Mar 25, 2010 7:12 pm
by xvivalve
Fully reconned 17ACR alternators available here, £38.00 plus postage. Two in stock
Re: ALTERNATOR UPGRADE FOR 1850H AND UNKNOWN ALOYS
Posted: Sun May 09, 2010 1:48 pm
by xvivalve
I now have 4 x NEW A127 alternators with 55amp stators in stock as well. £55.00 plus postage outright sale