TACH signal from alternator

[MrMarty51]

 

[alex1234]

ERRATA CORRIGE
in the post #30 I declared the ratio of 1:10
it's actually not fair at all
by dint of calculating circumferences, I abounded and calculated the circumference over circumference value of crankshaft pulley
I APOLOGIZE FOR THAT

the correct ratio is 1 : 3.136 for a calibrate TACH

The rest is correct

 

[alex1234]

whereas this AD-244 HD is 180A but amperage output comes with a small 42.60mm pulley that pushes it further....
should give 145A with a 57mm pulley
with a 62mm ??? I don't know, but certainly less
also the internal fans must run well to cool the alternator, and going on a bigger pulley maybe I could run into some problems, so better go with a factory pulley size.

think 57mm pulley, at this point is a good compromise, I won't have the correct TACH, but good enough
i will have a gap of
+40RPM to 600RPM
+130RPM to 2000RPM
+170RPM to 2500RPM
+200RPM to 3000RPM
up to a maximum of +270 RPM at 4000 RPM
think I can live with it

easy to find 57mm pulley for AD-244

 

[alex1234]

in light of all this....

I will have to resurrect the initial project to have the correct tach

 

[MrMarty51]

Take temperature readings of the alternator driving around town for about a half an hour, then, after a good run with the truck at highway speeds for maybe a half an hour.
Change to the pulley that will give You the proper reading on the tach and run the same course and see what variation You get in temperatures.
One of those infrared thermometers should work mighty fine for such an experiment .
If the temp readings are not that far off then probably not much to be concerned about.

 

[alex1234]

temperature could also be tested

but the lower amperage is a given

 

[MrMarty51]

temperature could also be tested

but the lower amperage is a given

And that too can be measured and monitored as You drive.

 

[dbrannon79]

you shouldn't see a decrease in amperage output while running down the road even with the larger pulley, only at idle and with a load like with the blower fan on high and the halogen headlights going.

as for temp. I have not ever measured the temp on my alternator (AD244) but I do know that in the mornings my volt gauge is up at 14 and after a 30 minuet drive I have noticed my volt gauge down to 13 or so. So heat does equate to a lower output.

 

[alex1234]

this is an AD244 alternator 180A output, with 100A at idle, this amperage is due with the over spin from a very small 42.60mm pulley.

now, if i swap pulley with a 57mm pulley, output amperage comeback to stock amperage 130/150A - 140A is acceptable, which is the amperage I expect

going with a more larger 62mm pulley, it will further lower amperage, it's a given, you don't need to test for know this.

a lower amperage is not what i need

 

[alex1234]

to make it as clear as possible the alternator is an electricity generator
faster the rotor spins, more electricity will be produced, up to its output limit
if other factors do not change, temperature, ect. rotor speed is the only variable

can be represented by a parabola that increases, until it reaches its peak when the output limit is reached and then tends to flatten.
I don't know exactly how many rotor revolutions it can reach its peak, I haven't found any information on AD244, but usually around 10000 rpm

the rotor in our case is turned by the pulley

at idle 600 engine RPM / vs. alternator pulley / rotor revolutions
OD 42.60mm / rev. 2688
OD 57mm / rev. 2010
OD 62mm / rev. 1848

at 2000 engine RPM / vs alternator pulley / rotor revolutions
OD 42.60mm / rev. 8960
OD 57mm / rev. 6700
OD 62mm / rev. 6160

at 3000 engine RPM / vs alternator pulley / rotor revolutions
OD 42.60mm / rev. 13440
OD 57mm / rev. 10050
OD 62mm / rev. 9240

assuming it reaches 180A at 10000 rev
180A will be available when engine RPM is at:
OD 42.60mm / 2232RPM
OD 57mm / 2985RPM
OD 62mm / 3246RPM

with pulley OD 57mm -37% efficiency
with pulley OD 62mm -45.4% efficiency
this with the limited data available

 

[alex1234]

presumable, indeed very likely that it is an OEM 145A at 10000 rev and reaches 180A only with overspin at 13/14k rev
it wouldn't surprise me
presence of the small pulley leads me to think this
absolutely in line with the usual commercial tactics

 

[Husker6.5]

you shouldn't see a decrease in amperage output while running down the road even with the larger pulley, only at idle and with a load like with the blower fan on high and the halogen headlights going.

as for temp. I have not ever measured the temp on my alternator (AD244) but I do know that in the mornings my volt gauge is up at 14 and after a 30 minuet drive I have noticed my volt gauge down to 13 or so. So heat does equate to a lower output.

That's not due to heat, that's because of battery charge condition. You see 14+V to charge the batteries due to discharge from glows/cranking, then 13+V to maintain once the batteries have been charged back up from starting.

 

[jrsavoie]

It doesn't seem like the electronic tach I bought for the Toro was very expensive or hard to install

 

[alex1234]

I preferred go with OD 57mm for not to lose too much on amperage output
not that hard to find online with overseas shipping, bought it on ebay.
now i will have to wait 3 to 4 weeks....

 

[alex1234]

come on guys!!!

you'll be happy to know that the initial project is definitely back in the limelight

 

[DieselAmateur]

@alex1234 sorry I wasn't able to get you the shipping quote yet, are you no longer interested in the 62mm pulley? It seems to have the correct seat size between pulley and alternator housing. Sounds like you're moving in a different direction, but if you still want the pulley it's yours

 

[alex1234]

Hi DieselAmateur,
I have to thank you for your availability and kindness
not having heard from you since, ... thought your pulley didn't have the correct seat size for the alternator
then doing calculations I preferred the compromise of OD 57mm pulley over OD 62mm, in order not to lose too much amperage on range

 

[JMJNet]

this is an AD244 alternator 180A output, with 100A at idle, this amperage is due with the over spin from a very small 42.60mm pulley.

now, if i swap pulley with a 57mm pulley, output amperage comeback to stock amperage 130/150A - 140A is acceptable, which is the amperage I expect

going with a more larger 62mm pulley, it will further lower amperage, it's a given, you don't need to test for know this.

a lower amperage is not what i need

Yes, that is true. You loose the advantage of the better alternator.

 

[dbrannon79]

does anyone know what the standard size gasser pulley is ? I think Alex has one that's even smaller than the gasser puller. I have one here somewhere just don't have a true way to measure it. I do remember when I bought my truck it had one on it and the tach wasn't that far off.

 

[alex1234]

on old alternator model CS-130 the gasser pulley was OD 56mm...i got 2 of this
with 230 and later alternator the pulley has OD 57mm diesel and gasser

but you can swap for a lower or bigger OD pulley available for the model