Another Searz Veteran? I notice you use the term "true horsepower", so I thought I might enlighten some un-initiated folks here. In the "olden" days .. alot of searz/craftzmen stuff, would advertise electrical tools using locked rotor current to calculate horsepower .. including compressors. Sometimes .. using start current, which can easily be several multiples of running current. Amps times volts (watts) divided by 746.
James Watt invented "horsepower" to market his steam engines to replace mules and horses in mining operations. One horsepower, can lift 550 pounds one foot in one second. Wth the advent of electricity .. someone figured that to be 746 watts. Anyway .. using locked or startup motor current was a marketing ploy .. haven't had a searz catalog in mabe 25 years .. hope they have cleaned up their act
I have here, an old craftzman twin cylinder new in '76 as I recall .. cast iron .. 20 gallon tank .. came with 2hp .. put a twin capacitor 3hp on it mabe 20 years ago. It works .. never re-built .. gotta small leak .. but hardly ever use it anymore .. takes 220 ... solar off-grid here now. It was made by Campbell Hausfield. Certainly ... cast iron is the way to go for the bigger units.
A few years ago .. bought a Ridgid "portable" twin tank .. basically for nail guns .. very similar to the one offered at HD as a reconn Campbell Housfield .. which is oiless. It has become noticeable noisier over the last six years .. but mostly used for occassional tire inflation these days .. 3/4" impact wrench needs the big guy, and the 18v dewalt 1/2" impact has far exceeded my expectations and is truly "portable".
Cast Iron .. for the big guys .. Oil-less works fine, but as noted in this thread, tends to get noisier with time and use. To this day ... I Always consider advertised horsepower ratings to be suspect ... compressors ... bench planers .. you name it. Caveate Emptor as they say. A $20 Kilawatt from NewEgg or where-ever, can be most enlighting
