110 amp alternator upgrade

[speedracer]

Hi all,

Merry Christmas, Happy New Year and all that

Does anyone know if one of these would fit a Sprint?
(It fits the sixes, Spitfire and Stag so I'm assuming so)

http://www.rareelectrical.com/p-13400-n ... -stag.aspx

Cheers,
Garth

[soe8m]

Why would you need 110 amps for. They eat v belts with those heavy rotors inside.

Jeroen

[speedracer]

Running electric water pump + controller + electric booster pump + thermo fan + multi spark...
And I'd also like to put some charge into the battery

Voltage gauge struggles to get to 13v

[Galileo]

Mine struggles to get to 13.5v depending on what's on. If my gauge is vaguely accurate, and I've got the headlights, wipers and the fan on then I'm looking at a shade under 12v. I've got the original 17ACR alternator, and it's rated at 35amp. Maybe something a bit warmer like a 18ACR (43 amp) or A127 55amp variant in my opinion would be a better bet, as reckon that 110amp is a bhp robbing v-belt shredding monster of a overkill swap!

[speedracer]

I'm running a 55amp Bosch alternator at the moment

[gmsclassics]

Hi Garth

I used to have terrible trouble with 'Lucas' style alternators on my race car burning out even with bigger pulleys. I've since fitted a 70A Unipoint LXA119 (UNI 1103) and never had the slightest issue. I mention this as the auto electrician I used told me it came from Oz.

It fitted fine although the wiring terminal have different fittings.

I run a Davies Craig 110 EWP, 12" radiator fan and the starter has to work hard to turn this engine over. Only gauge I don't have is a voltmeter so can't tell you what volts it reads when. Batteries seem to last the usual amount of time.

Hope this is of some help

Geoff

[Galileo]

Sounds like a 70amp might be a good compromise then from Geoff's experience, but you should consider uprating the battery feed cable to carry the increased current.

[sprint95m]

Running electric water pump + controller + electric booster pump + thermo fan + multi spark...

You can reduce the load by altering the plumbing to use one pump and a remote thermostat, thereby getting rid of the booster pump and controller.
There is an diagram and photos towards the end of this thread:
http://sideways-technologies.co.uk/foru ... s+%2Bcraig

As I said in the thread the standard Lucas 16ACR coped with this set up.




Ian.

[MIG Wielder]

I've always reckoned that the voltmeter ( just like the temperature gauge ) should be labelled " For indication only. "
Simply because of where its wired. Its on the end of the battery positive lead connector block, then a thick brown wire to the Ignition switch, then back to the fuse box along the white wire, and then finally down another white wire with various low current stuff hanging off it. Ideally it should be on the battery + , but that would suck current all the time and drain the battery. So its making the best of a bad job -and after 49-odd years- iffy connectors. So I'd always correlate the voltmeter reading with a DVM check under the same conditions.
Anyway to answer the original question, a 110 A alternator given the same current conditions will run cooler, the internal components being run furthur from their maximum ratings will be more reliable, the brushes will be wider and last longer, but yes, I can see the rotating components will be larger so more stress on the fan-belt.

viewtopic.php?f=6&t=31779&p=295744#p295744

Here is where I did a calculation of the maximum current on an 1850.
About 45 A . So with an EWP80 at 7.5A and an EBP15 at 1.3A plus an electric fan at 10A estimate , a 70 A alternator would be fine.
As Galileo mentions it all falls over when you look at the size of the cables from the standard alternator to that connector block.
I had a look at wire sizes / voltage drops and just 1meter of 2.5sq mm cable will drop 750mV at 100A . 6.0mm will halve that but that is thick cable and as has been mentioned may need a connector change. The 9.5mm large connectors are only rated at 47A.
But if the alternator needs changing anyway I'd go for it. I also have the 60A Bosch unit on my 1850 and its been not trouble for 4 years now.
Tony.

[Carledo]

Running the Voltmeter as a standalone from either the ignition switch or the unfused side of the fusebox would probably help it's accuracy. At least within the limits of the guage itself.
There is not much to stop you from making a a new alternator lead that goes direct to the starter (or even the battery itself) rather than through the 4 way. The 4 way will still be fed and thence power the rest of the car.
A bigger battery would be a good idea too, even if you have to dispatch it to the boot to get it in. I have an 075 type in the boot of the Carledo and have not had to charge it once since fitting it 3 years ago. The front mounted 038 would flatten very quickly cranking my 2.0 Vauxhall motor even though it was new. It's another case of Leyland not upgrading enough peripheral bits to go with the Sprint engine, The stock battery and alternator is the same on a Sprint as a 1300 Toledo. The original Carlton 60amp alternator is plenty for the Carledo since I don't have much hanging off it, just lights, wipers, heater fan (no HRW or O/D) and a high pressure fuel pump.
If the worst comes to the worst, it would probably be possible to buy/make/adapt some multivee pulleys to run the alternator from and avoid the belt shredding you would get from a single V belt with that powerful an alternator.

Steve

[speedracer]

Lots of good stuff in those replies - thanks all!

To fill in some blanks
- not to keen on changing the plumbing as the EWP etc does a really good job of keeping temperature under control for me
- I'm also running an electric fuel pump
- the battery is big (620 cca) and in the boot (and is left disconnected for the 360 days a year the car isn't driven)
- from memory, on more than one occasion I've killed the regulator on the alternator following "spirited" (~6k rpm) driving

The brown lead from the alternator to the terminal block is approx. 4mm in diameter and looks very original, so potentially i'm not even getting the use of my 55amps? Might try some new fatter copper.

I'll see if i can track down an LXA119 - looks like they are branded "OEX" in Australia...

I assume that putting a multimeter across the terminal block and body when the engine is running will give me an indication of how accurate the in-car voltmeter is?

Cheers,

[MIG Wielder]

Lots of good stuff in those replies - thanks all!

The brown lead from the alternator to the terminal block is approx. 4mm in diameter and looks very original, so potentially i'm not even getting the use of my 55amps? Might try some new fatter copper.

I assume that putting a multimeter across the terminal block and body when the engine is running will give me an indication of how accurate the in-car voltmeter is?

Cheers,

Hi Garth, With an overall outside diameter on the thick brown wire of about 4mm, the copper conductor is probably going to be 56 x 0.3mm^2 stranded cable or 12 A.W.G. which is rated at 41A continuous. I'll see if I can measure one up when it stops raining. This is typically 5.2mOhms /meter , or will drop 500mV at 100A.
For 75A continuous current 80 x 0.4mm^2 or 8 AWG would be better. This will drop 200mV at 100A. But this is thick cable even in flexible stranded format. A lot depends on exactly how much current for what time period it'll be running.
Jeroen (soe8m on here ) would be a good guy to talk to on this as he is in the business of wiring.
Hi Jeroen !
Yes, a multimeter actually across the battery would be good , but the circuit needs to be tested under load. Try main beam headlights + the heated rear window both on at 2,500 r.p.m. steady engine speed. This will give a good idea of the difference in reading between the dashboard voltmeter and the voltage actually across the battery.
HTH,
Tony.

[Galileo]

I've thought about testing the alternator output at the battery to test my gauge, but when the gauge drops to 12v the indicators almost stop flashing so...

In all seriousness, I really must do it sometime, and sort out the electrics with something a bit more modern involving relays and more than 2 fuses rather than relying on what was the height of automotive wiring fashion in 1965 , but I try not to use the car too much in winter.

[tinweevil]

I know it's only a photograph but I'm exceedingly dubious about the red wire in that picture. 110A would be 16mm², the small end of battery size wires. That looks like 4mm². Nor is it expensive enough for 110A, the one on the Golf I had that was around that rating was wickedly priced (and lasted about 10 minutes on average). Nor is is big enough, that's a standard ACR casing, 3 time the capacity in the same shell smells wrong. And as Jeroen says, pulling that round on a v belt with a pulley designed for 1/3 the load?

It could be legit but I'm seeing nothing that makes me think it even might be.

[soe8m]

According the weight and diameter it can be a 110 amp. The main power goes with a ring terminal behind the nut.

There were times i had with main beam about 800watts front lamps in total and used alternators of around the 100-120 amps.

The V-belt problem could easily "repaired" at the roadside.

Jeroen