Volvo D2 50F low budget switch to 24V: which 24V school bus alternator fits?

[CaptainRivet]

Originally Posted by kenbo

Ignore previous comment, serious brain cramp. Should have said swap the 12v voltage regulator for a 24v version

That means I just remove the regulator/rectrifier, get a Balmar 624 external regulator and have a 24V 55A alternator?
…sounds to good to be true. My 2 engines are like new with 140h, so do the alternators.

It will be a 24V 65-70A alternator as efficiency gain from 12 to 24V is 10-15% higher due to less heat losses plus moving heat away with the regulator, so realistic 24V 40-45A from one alternator. Change pulley from 62 to 48,6mm (from D4-220 with same alternator) changes gearing from 1:1,63 to 1:2 and more amps low down and overall.
All I want…

[kenbo]

All in all I think that you would be better served with something like this
https://www.amazon.com/ALTERNATOR-FI.../dp/B013W65RTM

I believe it's a direct replacement.

[CaptainRivet]

Originally Posted by CaptainRivet

That means I just remove the regulator/rectrifier, get a Balmar 624 external regulator and have a 24V 55A alternator?
…sounds to good to be true. My 2 engines are like new with 140h, so do the alternators.

It will be a 24V 65-70A alternator as efficiency gain from 12 to 24V is 10-15% higher due to less heat losses plus moving heat away with the regulator, so realistic 24V 40-45A from one alternator. Change pulley from 62 to 48,6mm (from D4-220 with same alternator) changes gearing from 1:1,63 to 1:2 and more amps low down and overall.
All I want…

Does this work, yes or no?
Having 2 new alternator that are suitable, why buy new?
Plus the Volvo alarm system, MDi and D+ hassle with aftermarket no direct replacement alternators plus pulley alignment….
They are my 3rd fallback charge source…simply has to work and not burn out and max I can get…

[kenbo]

A 24v regulator will work. Removing the rectifier to a remote location will remove about half of the internal heat. But here are the downsides, your low rpm output will suffer and the stator windings will not be matched perfectly to the new rotor-induced field.

It will work but not as well as a matched 24v alternator. You may have more invested in the conversion than the new one I posted earlier.

[CaptainRivet]

Originally Posted by kenbo

A 24v regulator will work. Removing the rectifier to a remote location will remove about half of the internal heat. But here are the downsides, your low rpm output will suffer and the stator windings will not be matched perfectly to the new rotor-induced field.

It will work but not as well as a matched 24v alternator. You may have more invested in the conversion than the new one I posted earlier.

Charging directly my 24V 560AH starter and house bank, so I need an external regulator anyhow.

Difference is if I get a 24V direct replacement having D+ and internal temp control (which most of the aftermarket alternators are lacking) I use the Nordkyn VSR200 regulator Module and keep internal regulator and therefor save all the hassle with loosing D+, internal temp control and the Volvos warning system with MDI box.

Is it a direct replacement, means D+ with internal temp control plus yellow sense wire and pulley alignment works???

[kenbo]

From looking at the dimensional specifications it looks like a direct replacement. Why don't you compare the dimensional sheets and confirm.
I can't speak to the D+ and MDI issues but it seems to be in hand with the Nordkin regulator.

[CaptainRivet]

Originally Posted by kenbo

From looking at the dimensional specifications it looks like a direct replacement. Why don't you compare the dimensionalgines sheets and confirm.
I can't speak to the D+ and MDI issues but it seems to be in hand with the Nordkin regulator.

From pure dimensions I know now several that will fit or can be modified to fit BUT pulley, pulley alignment, belt size, spanner add easily another 300 Euro and that it can be controlled by Nordkyn regulator to avoid the alarm/MDi issues and keep Volvo warranty which adds another 350-400EURO so in total again 1000Euro for 2 engines =2000Euro for 80A charge current max, mostly 40A.
An alternator 24V min 60A for around 250Euro where all fits plus a Nordkyn makes sense from Budget solution for 600Euro.
For around 900Euro you get a 24V 70A balmar kit with regulator all except the d+/MDi hacking.

Then it’s much easier, keep the 2x 12V 115A Mitzi, get 2xOrion smart DC to DC 12/24 15A and max one alternator out which you use anyhow to motor or motorsail, seldomly both engine. Costs 500Euro and all set to transfer to 24V bank.