[george kujanski]

I also took a look at the Summit site last nite. I need to check the Powermaster site to get clarification on the housings they use...i.e. 10SI or 12SI and how they rate their output.

2400 RPM, if engine speed, should be about 5000 RPM alt shaft speed, at which the alt should put out it's max rating. If 2400 is the alt shaft speed, that would equate to about 1200 engine RPM (assuming a 2:1 pulley ratio). So if it's the latter, that's fairly good output since you need high output current running fans at or near idle, otherwise the battery won't be charging with the hgih fan load.

With heavy idle loads like fans you need 50 to 60 amps available near idle; that's the critical spec. Max output current doesn't mean much for that application.

Another point on specs: alts should be rated for output at higher temps, which is the underhood environment. Ratings done with surrounding air at room temp will always be higher, but are not representative of reality.

Back when I worked in charging systems, we rated all of our alts with the machines hot, with surrounding air at least at 50 degrees C. IIRC.

Just some info gathered over the years.......

George