3800 blower info

Several of you have asked for more information
so here goes.

The blower in the picture I posted is an M-90 Eaton from a T- Bird Super Coupe.Mounted up
side down.There are 2 versions early and late. The late is preferred because it flows much more air and is able to be ported to produce even more. The early is not a bad piece, maybe 400
h.p. max. If you have a choice go for the late version. The difference is easy to tell. The early has an oval intake opening and the late has a rectangular opening.Either may be mounted any way needed upside down,sideways, whatever. Oiling will not be an issue. On the subject of oiling, never use anything but the synthetic oil from Ford or G.M.regular oil will kill the bearings almost immediately. Eaton's are positive displacement meaning they must be used as draw through installations. Don't even think of trying to use as blow through. They will blow up the stoutest box you can build.Eaton says the rev limit for an M-90 is 14,000 RPMs. I've been running mine @ 18,000 for 5 years. If you do reach too high an RPM for the blower it will start falling on it's nose and lose power,just like over revving an engine.M-90s are capable of enough air flow for a little over 500 h.p.. The more cubic inches the less boost. On my 292, turning the blower @3 to 1 it makes 12 lbs. boost @ 18,000 blower speed.I have seen a ported (called S package by Magnuson) run @ 22,000 for several years in a drag car.
The 3800 V-6 Blowers have 2 versions ( "95 down have M-62s, 30 cu.in. less displacement.
These had to turn too fast and caused the front
bearings to go away.These were replaced by the bigger M-90s,but turned slower to make the same boost.Racers put the pulleys from the M-62 on the M-90s and had instant badass.I have dyno sheets for a stock short block Pontiac V-6
with cam,port job and headers and intercooler @537 h.p. with an M-90 squeezer.The problem with the V type blowers is they hard as hell to mount on anything but a V type engine.I've done it but it was not worth the work.
If you are going to use an Eaton be sure to use the bypass valve . Either the built in, thats on the V type or the remote from Magnuson. The bypass lowers inlet temp and drastically reduces power needed to turn blower when not in boost
(less than 1 h.p.) The remote can be used with the T-Bird units as well.Eaton blower can be found at swap meets fairly cheap. Damn cheap compared to other stuff available. Check front bearing for roughness. You don't want one with chewed up rotors. Early models did not have coated rotors.You don't want one with the coating peeling off. Magnuson will change front bearings for very little money.
Boost for 4 cylinders can be astronomical with these blowers. An M-90 on 2 liters will be in the range of 25 lbs. An M-62 will be about 16 lbs. This depends on pulley size, but attainable. Either would be in the realm of alcohol or need
an intercooler. One last thing, one of you mentioned cutting out to mount carbs in a different manner. If you have to weld in your plan. Change your plan. The cases and rotors
are so precisely machined any warpage will
destroy the whole package.They can be pinned
and epoxied though. Hope this informative. I would be happy to answer specific ??s on P.M.
Gemini EFI

 

Thanks, I've been thinking about one of these for a 250 chev. inline I just picked up. A buddy of mine has one on a 215 buick in a sand rail. Fuckin thing is an animal!