BJ41 24v Alternator alternative (1 Viewer)

[Jollopy41]

Hi guys,

So I swapped my old 24v alternator and I am slapping in a brandnew alternator from an Isuzu 4HF1. Some modifications involved with the altrrnator bracket, maybe my vacuum hoses too and probably changing the belt size.
I got a couple of questions:
1. From the previous alternator, it only had a rating of 25Amps. The new alternator has a rating of 50Amps. What are the advantages of having a higher rated alternator?
2. Would having a bigger vacuum pump have better improvements in the vehicles braking?
3. And lastly, would an internal IC be better than an external voltage regulator?

Thanks,

Carlo

 

[Feistl]

Bigger alternator will be able to supply more power to the vehicle, allowing you to run more lights, winches and after market accessories without running the risk of falling voltage or draining the battery. 50amp is still pretty low but depends how much stuff you want to power.

Unless the original vacuum pump was failing, then no more vacuum won’t improve brake performance. You would need to upgrade the booster to notice an improvement. There are lots of ways of improving braking performance but they all cost money.

Generally yes, an internal regulator tends to be more reliable and is a simplier design making it easy to change.

It should be ok, but take notice of the size of the pulleys on the new alternator. The pulley size is matched to the harmonic balancer, sometimes when swapping to a new engine the ratios will be different meaning you may not get much charging at idle. (Alternators don’t produce much power at low rpm, typically the “rated” amount is only above save 1800rpm but it varies depending on the type/brand)

 

[Jollopy41]

Bigger alternator will be able to supply more power to the vehicle, allowing you to run more lights, winches and after market accessories without running the risk of falling voltage or draining the battery. 50amp is still pretty low but depends how much stuff you want to power.

Unless the original vacuum pump was failing, then no more vacuum won’t improve brake performance. You would need to upgrade the booster to notice an improvement. There are lots of ways of improving braking performance but they all cost money.

Generally yes, an internal regulator tends to be more reliable and is a simplier design making it easy to change.

It should be ok, but take notice of the size of the pulleys on the new alternator. The pulley size is matched to the harmonic balancer, sometimes when swapping to a new engine the ratios will be different meaning you may not get much charging at idle. (Alternators don’t produce much power at low rpm, typically the “rated” amount is only above save 1800rpm but it varies depending on the type/brand)

Thank you very much Feistl. My cruiser is already running. I should observe her somemore and give ypu a feedback soon.

Thanks,

Carlo

 

[ybggziggy]

Hi guys,

So I swapped my old 24v alternator and I am slapping in a brandnew alternator from an Isuzu 4HF1. Some modifications involved with the altrrnator bracket, maybe my vacuum hoses too and probably changing the belt size.
I got a couple of questions:
1. From the previous alternator, it only had a rating of 25Amps. The new alternator has a rating of 50Amps. What are the advantages of having a higher rated alternator?
2. Would having a bigger vacuum pump have better improvements in the vehicles braking?
3. And lastly, would an internal IC be better than an external voltage regulator?

Thanks,

Carlo

Hi Carlo, how did this work out for you? I’m looking to replace the alternator in my ‘79 BJ41 and am weighing rebuild versus OEM versus compatible alternative. Thanks!

 

[Jollopy41]

Hi Carlo, how did this work out for you? I’m looking to replace the alternator in my ‘79 BJ41 and am weighing rebuild versus OEM versus compatible alternative. Thanks!

Hi Carlo, how did this work out for you? I’m looking to replace the alternator in my ‘79 BJ41 and am weighing rebuild versus OEM versus compatible alternative. Thanks!

its been more than three years already and sp far so good. I did not get a single "alternator" problem since swapping out my OEM alternator and just replaced my batteries last year.

 

[ybggziggy]

Good to hear, Carlo, thanks for your response. I bought an aftermarket alternator for Isuzu 4HF1 like you did and it's on its way. I'm debating whether to tackle it myself (hope too) but it will depend on if any modifications are needed to drop it in. Any insights, photos, etc. you can share are greatly appreciated (I know it's been a few years for you). Thanks again!

 

[ybggziggy]

In case anyone else refers to this thread I installed the new alternator (Alternator for Isuzu 4HF1 8972489141, 8973325020, LR280-501, LR280-506 - https://www.dbelectrical.com/products/alternator-for-isuzu-4hf1-8972489141-8973325020-lr280-501-lr280-506.html) and it fit much better than I expected (no hose or bracket modification). The one issue is that once I fully tightened it to the brackets the belt became slightly at an angle with the opposite pulley to the point that it smoked from rubbing when I started the rig. I loosened it a bit and it still seems to run a little hot. I probably need another adjustment to try to coax the brackets a little farther forward.

 

[roma042987]

In case anyone else refers to this thread I installed the new alternator (Alternator for Isuzu 4HF1 8972489141, 8973325020, LR280-501, LR280-506 - https://www.dbelectrical.com/products/alternator-for-isuzu-4hf1-8972489141-8973325020-lr280-501-lr280-506.html) and it fit much better than I expected (no hose or bracket modification). The one issue is that once I fully tightened it to the brackets the belt became slightly at an angle with the opposite pulley to the point that it smoked from rubbing when I started the rig. I loosened it a bit and it still seems to run a little hot. I probably need another adjustment to try to coax the brackets a little farther forward.

So, you're saying it doesn't actually fit.

 

[ybggziggy]

So, you're saying it doesn't actually fit.

Just voluntarily sharing my experiences. All can interpret and do with it as they wish.

 

[ybggziggy]

Just voluntarily sharing my experiences. All can interpret and do with it as they wish.

Final update: when I removed the old alternator there were several washers that I now realize were filling voids on the underneath bracket for the alternator. I didn't use them when setting the new alternator and before tightening it rocked about an inch back and forth and when fully tightened pulled the alternator toward rear creating the slight offset of the belt. Now with voids filled the belt is running smooth and cool.

 

[veiloctane]

I would talk to these guys at SBC aka M2kinc I have one of there 390A alternators in mine!!! its been awesome. they also have 24V alternators

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