Technical 40 amp regulator on a 30 amp generator?

What will happen if you install a voltage regulator with a higher amp rating than the generator it's connected to? Will the system still charge ok?
The reason I ask is there is no tag on my generator so I don't know the output. My thinking is that if I put a smaller rated regulator on a generator with a higher amp rating it will burn out something. But if I go the other way with a higher amp rating on the regulator than the generator I should be OK. Is my thinking wrong?

 

Generators are current regulated so that the solder at the commutator doesn't melt. If that happens, the windings are thrown out and the generator is junk. Putting a higher amp regulator on a lower amp rated generator can cause this to happen. Going the other way, lower amp regulator, will just limit how much current the generator will put out. It won't burn anything up, all it does it regulate the field current. However, if you don't know the amp rating of your generator you are just guessing. If it is the car in your avatar, I have data on a 47 Buick that says the generator was rated at 32 -34 amps. The information I have on a 50 -53 Buick doesn't give a current rating.

Also note that 3 unit DC voltage regulators are adjustable. You can adjust both the current output and the voltage output.

 

^^^ This.

Generators are limited by magnetic saturation. Once the iron pole cores are saturated, any additional current into them to try to increase power output is converted to heat.

This is also an issue with alternators, but because of their different design they make more efficient use of their cores.

 

The car is a 56 T-Bird. But they list both 30 and 40 amp generators for 56, and who knows if the stock generator is still in the car. There are no numbers on the generator. My avatar car is a 49 Buick with a Cadillac engine and an alternator.

 

I would assume that the 40 amp was fitted if the car was equipped with power seats/windows (and maybe top?). It should be larger than the 30 amp version also.

 

only one size 12 v ford gen. and everyone can quit worrying about the outputs --any reg and gen of the same a or b circuit is almost bound to work well enough!