Technical Eaton supercharger conversion to top carb mount

the eaton line of superchargers may not be hamb friendly but they are cheap and plentiful. the only drawback is most of them have a rear inlet. I know that magnuson and edelbrock have both made versions of this supercharger with a standard 4 barrel mount on top of the case. Does anyone see a reason I couldn't modify a standard Eaton M90 or M112 with an intake at the top and block off the intake at the rear?? I know some of the later generation M90's and M112's had a raised area above the rotors going about 1/3rd to halfway towards the front that intersected with the rear inlet.

looking to build a low budget, low boost supercharger that costs me little more than the junkyard blower and some fab skills. I would have to make a V-drive and probably an intake for it.

here is a supercharger from a supercoupe. it's an M90 which displaces 90cu/in as compared to a 4-71 which is 280. this would go in something like a flathead. I've seen guys run these on bangers and a V8-60 here on the hamb... most utilized the rear port. I would like to take that raised area at the back and bring it across level to fit a couple 97's on top. the vacuum bypass makes these nice to run around town and cruise... then have boost when you want it.



this pic I stole from the hamber who ran one on a v8-60. he put a 97 in the front as well but I don't know that he ever actually ran with it. this is an earlier version of the supercoupe m90 that doesn't have the raised area over the rear of the rotors.


If anyone has any knowledge on these I would love to hear it. I do know that the rotors don't like gas if they are coated. they came both ways and if coated it can be removed I guess. I have a few ideas on how to mount one up that would look pretty slick... so it doesn't look like I pulled a part off a late model car and hacked it on my motor....

 

I think that's a great idea, Kev
Would love to see it as you progress
Jim

 

The second picture comes from @blowby, as far as I know.

You could always ask him how well it works.

 

I have the same unit, and am considering something similar. Some folks are hesitant to run a draw thru with a carb,
because the unit was designed to draw air for port injection, and the fuel can supposedly affect the lube in the rear needle bearings. With some porting and polishing the unit will move a bit more air, lots of you-tube videos on this subject.

 

Rear needle bearings for Eaton M90

 

The needle bearing has a seal though.. don't see a real issue. I would like to run the measurements of the 90 vs the 112... I would like to find three carbs on top if possible

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I've thought about this to it looks like the M112 from a 1999 up Ford lightning might be the easiest to adapt.

 

The lightning or jag units are perfect

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I was looking at doing this on my v8-60hp. Where did you find the info on the v8-60hp that someone here did?

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Blowby did it.. search his posts

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Iam using the same one on a Dodge 6. Just making the manifold now.

 

What kind of cams would you guys recommend for a boosted flathead? I know for most regular engines small overlap etc. Is good to keep boost up.. but I've heard several flathead guys saying they used really radical cams with blowers?

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I've got an m90 in the shop I cant give away so I've been running the same thing around in my head. Custom manifolds and v-belt pulley. My understanding is gen 4 and 5 have the sealed bearings but the gen 2 and 3s do not. At least for the GM superchargers. I've got a gen 3. I don't want an MPFI setup but that seems to be the only way it will work and last. The bearings don't look like they'll interchange. Anyone know if the pocket could be machined for the later sealed bearings? I'd like to simplify mine by just plugging the bypass, I don't have the parts to operate the valve and I'm not too concerned by it. A Stromberg or 2 on a worked A banger has been a dream of mine for awhile but if I'm stuck using EFI, I guess I'd put it on a 2.3 or 2.5 Ford or something and do my best to hide the modernity. Then again that much boost on an A engine may not be a good idea. Seen a few on Buick/Olds/Rover 215s and they run EFI.

 

Hello I installed a jaguar compressor on my flathead but I can not put pictures, I do not know how to do, have you a solution?

 

As a side note , I have one on my roadster and although it does have all of the rear intake and port injection that you're trying to get away from , it has 42K miles on it and has run great with no problems . I brought this up as I thought that you might be interested in the reliability factor . Good luck with your project .

 

When I first met Jerry Magnusen in about 2001, I asked about running one of his Superchagers with a carb, at that time he didn't like the idea of running fuel through the case as the bearings were not designed to be run "wet". Some years later he brought out a blower with a carb flange on top so I assume he did something different with the rotor bearings. So adapting a carb or two onto that case may have problems. As to wether introducing the fuel/air onto the top of the rotors, the reason that design of blower works so well is the air flow along the length of the rotors where he claimed a 60% efficiency vs about 30% from a roots type blower that drops air/fuel onto the top of the rotors. I'm not sure but I think his design that mounted a carb, may have ducted the fuel into the end of the rotors in a "normal" fashion. So IMHO, you may have more trouble than it's worth.

 

Do you know what generation supercharger it is? Or what it came off of? Any pictures?

 

I am using an Eaton M112, I decided to flip the case to give me a bit more area to mate the carbs. Haven't run this yet but I think it'll work. I would agree with bellytanker that the supercharger isn't going to be as efficient in this configuration but the flathead only wants 3-5PSI of boost so it doesn't really matter.

 

Wow! Looks like you did almost exactly what I was thinking. I was going to drill and tap the webs after milling them instead of welding... also I was going to extend out the back to add one more carb if I had room.

Any more details on it? What ratio pulleys? How much psi? Motor specs?

Any good hints on places to find those blowers cheap?

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Another question on the jag unit.. what are the center dimensions of those ribs on top? Are they wide enough that the 97 venturis fit between them? Looks like it in the pic.

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May be a little too impractical but on , say a flathead FED they could be crank driven and draw through the original end opening.

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I picked up a Lightning M112 for $125 and a 2 bbl to 4 bbl adapter, welded some ears on it, still need to drill blower pattern bolts and open it more (bottom view)

 

Are these screw or roots style blowers?

 

Roots: http://www.eaton.com/Eaton/Products...rformance-aftermarket/Superchargers/index.htm