Hi Tony,Just how outdated are the ADC FB1 4001's?
Is there anything that can be done to improve the performance or efficiency? New brushes? New brush springs?
If it is in good shape, there is really nothing outdated about it. It would basically run the same as it did the year it was manufactured producing the same power levels as efficient as before.
Note "is in good shape", meaning no damaged parts either from abuse or neglect. It was class H, like still used today so insulation rating is good and no reason it won't be good for years or decades to come. The OE bearings we're sealed & lubed for life. Occasionally I see aged balance putty crack. That needs checking.
Brushes, springs, and commutator need inspection. Use original parts unless they're damaged.
Don't know particulars like previous application and intended future use, but about the only performance/efficiency enhancement I'd consider is enhanced cooling, or forced air flow thru the motor. A cooler motor will run more efficient and live longer.
Nothing wrong with using a series DC motor in a conversion. Actually benefits the first time diy EV builder. Sure, the modern AC EV drives have a lot to offer but come at higher level of cost and complexity.
PS. If you're going to use the FB1, consider having a reputable repair shop (EASA member) or forklift shop look at it.