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Hi! I've been browsing the forum for a couple of hours now, and I'm still not sure about the power ratings and equivalence between ICEs and DC motors.

I want to convert a classic 1981 Daihatsu Hijet Wide 55 microvan.

daihatsu.png

the original engine's specs are as follows:

Type: four-stroke, water-cooled two-cylinder AB20
Displacement: 547 cc
Power: 22 kW at 5500 rpm
Torque: 4.2 kg⋅m (41 N⋅m; 30 lb⋅ft) at 4,000 rpm.
Transmission: 4 speed.
Max. speed: 105 km/h

I want to at least conserve the same power and speed ratings, and ideally make it a little better. I want to achieve an autonomy of 100 km.

I found this forklift motor for sale:

motor.png

Type: Series-wound Brushed DC
Voltage: 48V
Amperage: 170A
Power: 6.5KW
RPM: "about 1500"

weight: 85 kg
length: 47 cm
diameter: 25 cm

So, the thing is that according to some posts, this should be ok, but The power rating seems too low. another thing I did was using the EV calculator, but the results seem to be off, as it says I would need a 50 KW motor to be able to achieve the specs I want.

I still can't seem to wrap my head around over-volting and brush-timing and such.

Any help would be deeply appreciated. Thanks a lot In advance!
 

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Hi
That motor sounds about right - it will have been in a forklift of about 4 tons

The current controls the TORQUE (and the heating)
The voltage controls the speed

So at 48 volts it will draw 170 amps at 1500 rpm to dive a 4 ton forklift

the 170 amps will be continous - you can go above that for a short period

The 48v will be for 1500 rpm - you will be able to go up to at three times that

Running at a higher rpm will mean that the fan works better

I'm using a similar motor at 340 v and 1200 amps - but that is a bit extreme

Most people would use about 500 amps and 150 v - which would give 75 Kw or about 100 hp

That will run the motor at a more sensible rpm - about 4000 rpm

Because of the higher rpm you will need to advance the brush timing - if you go through the forklift motor thread that will tell you what to do

FIRST thing
take more pictures of the motor - take the guards off the brushes and take pictures and hopefully the expert (Major) will tell you more about your motor
 
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