Eaton Gen 3 vs Gen 4 vs GM "gen 3"

[J57ltr]

I found some old pictures I took of differences in blowers from the Ford Gen 3&4 and the GM Gen 3 as you guys call it.

The pics are on page 3. Now tell me again why M90s before are referred to as Gen 3 when Eatons website back the. Listed them as Gen 4.

http://www.sccoa.com/forums/showthre...harger+porting

Jeff

[Cymaro]

So I'm thinking that GM only got the Gen 3 superchargers and maybe Ford got the Gen 4? Then the series 3 GM 3800 skipped the 4th Gen Eaton M90 and went straight to the Gen V?

[J57ltr]

There was a big discussion years ago about finding prototype M90's one had a screw on pulley another had a press on. There were case differences that were hybrid between the older and newer. There's also a difference between the M and MP and I think there was another with a different inlet/outlet configuration. An older version of that page also had the older supercharger listed as well. Maybe my mind is failing me. The 94-95 had the top supercharger, exact dims and everything. The coating is different between the GM and Ford M90's, but the inlet port and outlet port are the same even though they are inverted. Earlier blowers had a inlet that closer to the tips of the rotors and no guidance for air entering which causes turbulence and drag. Later models were So much more efficient that the blower drive pulley is larger. Other things were non coated rotors, and inlet adapter were modified as well.