Blower motor swap

[toopy]

I think that’s the most efficient design for a ‘forward curve’ centrifugal fan of this type, the air is pulled in axially and flung out tangientally. I think it’s a fan design that’s delivers a very high flowrate for a given size. Try googling ‘forward curve fan’. We have massive versions at work for building ventilation.

Thanks for that, like i said, happy to be corrected

https://www.rs-online.com/designspark/fan-types-why-choose-a-forward-curved-centrifugal-fan

So the fans don't so much cut through the air, but rather they scoop it up and throw it out!

 

[Rob Gaskin]

I tested my Honda fan in the box (I'm now ready to re-install the box). I also removed the fan and re-installed the old one for comparison.

The new fan is better rotating one way than the other, however both ways are better than the original. I wish I had a kids windmill to show the results, I used something suspended from above and noticed how far it was displaced in all conditions. I rigged up a battery and 'patched' wiring - thank goodness I used a fused lead because I blew one!

Anyway the Honda upgrade is probably twice as powerful as the Datsun output. That is with the polarity reversed (no problem as the motor is plastic and insulated. I didn't have to modify the box and can revert to Datsun anytime. It would be nice to have a rheostat in circuit but that's for another day.

 

[toopy]

With these replacement blowers being fitted and with them the higher wattage motors involved, is the OEM resistor pack up to the job in the long term or at all?

 

[Turn & Burn]

With these replacement blowers being fitted and with them the higher wattage motors involved, is the OEM resistor pack up to the job in the long term or at all?

They’ll def get a bit more stress, but the increased airflow should help keep them cooler! You could change out for a resistor pack from a Honda for the ultimate upgrade.

 

[Rob Gaskin]

The resistors are strange, I haven't seen them glow and I can't measure the resistance because it's low? If they do blow you don't lose the fan completely, just the speed control.

 

[AliK]

Just caught up with this thread. Love it! Looks like the Jazz motor is the winner for RHD. My only two thoughts were:

1. beware of the resistor packs. Many years ago, the ones on my dad’s MK 1 mondano started to go and we could smell them. We just pressed on for another 1000 miles with the windows slightly open. When I bought replacements, they were way beefier. The problem was the heat from the resistors had started to melt themselves and the insulation on the wiring nearby.

This was clearly going over a number of years as Ford had under rated them and it was a gradual failure.

2. While a higher rated fuse will work, is the rest of the wiring up to the job? Was it ever gauged to deal with this much extra current?

On low speed you are stressing the resistors on high speed you may be stressing the wiring.

Please be safe and don’t have a car-b-q!! [emoji15]