[Milsurplus] Mil generator

[Kenneth G. Gordon]

> Have a mil surplus generator from the late 40's (Army), early 50's (Air Force) and/or 
> mid 50's (Army Corps of Engineers) (has tags from all 3...not sure if 1 or all are 
> correct)

Hmmmm...interesting. Could you take some photos of the various tags and pass 
them to some of us? I think we can help you.

> 
> Has several ratings on power depending on voltage and phase...all about 10K at 
> 220VAC

OK. The military had quite a number of generators which were able to provide the 
following voltages, depending on where a particular switch or a set of jumpers was 
set:

110 VAC at full power (whatever that was) single phase

110 VAC at FP, three phase

110/220 VAC single phase

220 VAC three phase

All the above at full power (10K in your case).

I had a 5KW genny like this once.

Is yours something like this?

> 
> Has a 4-cylinder motor in it that is full to the top with water....

Usually, despite that type of problem, that can be fairly easily fixed. Do you know 
the cause of there being water inside the cylinders? At least I assume that is what 
you mean: water both inside the cylinders and in the crankcase? Possible causes 
are blown head gaskets (very easily fixed), cracked head (not as easily fixed, but 
still possible), cracked block (again, not as easily fixed as a blown head gasket, but 
still fixable).

If your engine's block or head is cracked due to water with no antifreeze being left 
in it during extremely cold weather, usually below zero, then in my experience, the 
engine IS ruined and although it COULD be salvaged, it is probably not worth the 
effort. However, if this really is the cause, the radiator would be ruined also, and 
you have not indicated that is the case, so I am betting on the blown head gasket.

> 
> Anyone have any info on the HP that it should have so I can locate a replacement 
> engine...not looking for a restore to original...this is for emergency power for the 
> house....

As Robert Downs told you, the conversion factor for THEORETICAL HP is 746 
watts, more or less, per HP. So at 10 KW, that is about 14 HP, more or less. 
However, in my experience, it is always wise to about DOUBLE that for a practical 
engine, so say at least 25 HP, and I would use a 30 HP engine.

Since as Robert Downs mentions, the HP vs RPM curves for both gasoline and 
diesel engines are quite "steep", you really should know the RPM at which the 
generator normally runs. Then you will have to choose a replacement engine on 
the basis of its HP/RPM curve.

Now, here is where it gets interesting: in my experience, those gen plants which 
have the voltage choices listed above available, normally use a 2 pole alternator. 
This means that for 60 Hz, the generator has to be turning at 3600 RPM constantly.

(60 CPS * 60 seconds = 3600, and each cycle contains two "pulses", one per pole)

4 pole alternators turn at 1800 RPM to provide 60 Hz, 6 pole alternators turn at 
1200 RPM, 8 pole alternators turn at 900 RPM, and so on.

Since those military engines are far more robust than automotive engines, if it were 
ME, I would rebuild the engine you have rather than try to find a different engine.

Ken Gordon W7EKB