blower RPMs?

aroot1

SCCoA Member
I am playing around with the idea of using a supercoupe m90 on a carbed application, a 272 y-block 56 f100 draw thru 4 barrel nonintercooled. What kind of RPM range do these spin on our SC's, stock and at diff overdriven %s? I am trying to figure out drive ratios, and the boost levels that they would produce. I believe I have a workable pullie arangement that gives me a 1.87:1 drive ratio. The engine will be a 5000 RPM max, which is around 9500 blower rpm. I know boost is a measure of resistance to air flow, and restriction on the inlet is huge, but what sort of boost #s do you guys think this could produce?

I have also seen one of the companies who specilize in v6 power have a carb conversion kit, but I have not been able to find it now that I am actually looking:rolleyes: I was planning on just building a simple 90 degree adaptor box from the rear inlet to a 4bbl flange, but if the kit is reasonable, no sense in reinventing the wheel:p Any one know of the, or a kit like this?

Thanks

Adam
 
I am playing around with the idea of using a supercoupe m90 on a carbed application, a 272 y-block 56 f100 draw thru 4 barrel nonintercooled. What kind of RPM range do these spin on our SC's, stock and at diff overdriven %s? I am trying to figure out drive ratios, and the boost levels that they would produce. I believe I have a workable pullie arangement that gives me a 1.87:1 drive ratio. The engine will be a 5000 RPM max, which is around 9500 blower rpm. I know boost is a measure of resistance to air flow, and restriction on the inlet is huge, but what sort of boost #s do you guys think this could produce?

I have also seen one of the companies who specilize in v6 power have a carb conversion kit, but I have not been able to find it now that I am actually looking:rolleyes: I was planning on just building a simple 90 degree adaptor box from the rear inlet to a 4bbl flange, but if the kit is reasonable, no sense in reinventing the wheel:p Any one know of the, or a kit like this?

Thanks

Adam

You will Definately not want to spin it much faster than 10k without a intercooler. Are you planning on using a early model (oval intake port) or a late model (rectangular intake port)? The late models produce less heat.


http://www.sccoa.com/forums/showthread.php?t=24783

http://www.capa.com.au/eaton_m90data.htm

Hope those links help a little
 
you should make about 3lbs of boost with that setup

ideally u want to spin the blower at 18,000

youll be fine without an intercooler, i run mine without intercoolers with no problems, i have a custom crank pulley i had cut on our cnc machine, if u search my username youll find a thread with the custom pulley, i have specifics on blower speed and what not there
 
Thanks for the links. I am gonna be at max of 5000 on the motor, which would be just under 10,000 blower speed. Looking at those charts, it probly won't be making too much heat yet, and will spin that hard for short periods of time. If that is a problem I could always add water/meth cooling.

I am going to use the early blower to start bcause I have a couple lying around:D If I build the carb adaptor myself I will make it so that I can port the opening to match the late blower later if I get a chance to up grade. I hadn't thought about the early model making more heat, may have to think about that.

Was hoping to see alittle more boost, kinda seems like an awful amount of trouble for so little. With the front motor mount on these trucks I can only fit a 6.5 maybe 7 in crank pullie (and that will be WAY close), and have a 3.5 upper which looks about as small as you can go. The pullies are cog so belt slip won't be a problem. I dont see much chance of a jackshaft arrangement to up the speed any. Any other suggestions for upping the boost some?

Adam
 
Got a private message that morana was the conversion I had seen, http://www.moranav6racing.com/category.html?CategoryID=47#155

That kit bolts a carb on what is normally the outlet, so must reverse the flow thru the blower:eek: At a min they would have to turn the lobes backward, how do they do that? The unit isn't designed to work that way, what does that do to efficency?

My plan was to turn the blower upside down and bolt to a box type intake, and mount the carb behind on a 90 degree elbow. The reverse setup would work even better as it would help move the snout forward to more easily align the pullies, and may even alow for a simple 4bbl maniflod adaptor plate/elbow.

Anybody ever use on of these adaptors?
Adam
 
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Got a private message that morana was the conversion I had seen, http://www.moranav6racing.com/category.html?CategoryID=47#155

That kit bolts a carb on what is normally the outlet, so must reverse the flow thru the blower:eek: At a min they would have to turn the lobes backward, how do they do that? The unit isn't designed to work that way, what does that do to efficency?

My plan was to turn the blower upside down and bolt to a box type intake, and mount the carb behind on a 90 degree elbow. The reverse setup would work even better as it would help move the snout forward to more easily align the pullies, and may even alow for a simple 4bbl maniflod adaptor plate/elbow.

Anybody ever use on of these adapters?
Adam

Adam,

I think you would be much better off mounting the blower offset to the side enough to leave your carburetor in it's current location. Then just make an adapter for the back of the blower for attaching an air filter, and plumb the blower outlet directly to the carburetor. This would be arranged the same as you would do with a centrifugal blower and carburetor.

The carburetor will have to be modified to make it work in a blow through configuration, and will also need an adapter to attach the pipe from the blower outlet, but that will be a lot better than that silly setup that Morana came up with. You are correct that the blower on that Morana thing would have to be turned backward, and that is a bad idea for numerous reasons.

David
 
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Yeah David,

I thought that Morana set up just looked to easy :cool: All my under standing from this site about how these blowers work made that setup seem questionable. Exactly how would you go about turning the blower backwards? I can't come up with a GOOD idea for the belts to do that.

My knee jerk reaction was "I don't want to do a blow thru" (just don't LOOK right on an old 50s rig). After a little thought you may be right. It would alow intercooling for one. The carb mods aren't much different, boost ref the power valve, or remove it and jet rich. Only real added mods would be a fuel press reg with a 1:1 stepup for boost and a fuel pump capable of a high enough pressure at full boost. It may also make more boost without the restriction of the carb in front of the blower.

Another thought is that several other forums had posters who felt that running fuel thru the blower would wash out the grease in the rear bearings. Awhile back I talked to eaton about a carb ontop of a m112 and they never said anything about it being a problem.

Adam
 
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My knee jerk reaction was "I don't want to do a blow thru" (just don't LOOK right on an old 50s rig). After a little thought you may be right. It would alow intercooling for one. The carb mods aren't much different, boost ref the power valve, or remove it and jet rich. Only real added mods would be a fuel press reg with a 1:1 stepup for boost and a fuel pump capable of a high enough pressure at full boost. It may also make more boost without the restriction of the carb in front of the blower.

Take a look at this page to see how Studebaker did it back in the 50s.
http://www.1956goldenhawk.com/superchg.htm

Another thought is that several other forums had posters who felt that running fuel thru the blower would wash out the grease in the rear bearings. Awhile back I talked to eaton about a carb ontop of a m112 and they never said anything about it being a problem.

Shouldn't be any problem at all. See link.
http://www.4wheelparts.com/Performa...&emlprox=out&gclid=CKqn58Tgi7UCFUid4AodLG8Ahw
 
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Take a look at this page to see how Studebaker did it back in the 50s.

:DYeah, so did ford on the t-birds:D and fairlanes. Still think the carb on top of the positive disp just looks so much more "correct". Plus on these trucks you could put an 18 in tall set up and STILL have room. Anyway gonna spend the w-end looking, measuring, drinkin beer and see what we come up with:D

Adam
 
Take a look at this page to see how Studebaker did it back in the 50s.

:DYeah, so did ford on the t-birds:D and fairlanes. Still think the carb on top of the positive disp just looks so much more "correct". Plus on these trucks you could put an 18 in tall set up and STILL have room. Anyway gonna spend the w-end looking, measuring, drinkin beer and see what we come up with:D

Adam

Adam,

To put the carb on top, you'll need an old school blower with a top inlet and bottom outlet.

David
 
My plan was to flip the blower upside down (outlet facing down), and mount to the top of a box type intake manifold with a hole for the outlet to feed. The carb would be mounted to a 90 degree "elbow" adaptor to the stock inlet so the carb was above, but behind the blower. It wouldn't be on top exactly, but would have sorta the same look. The two problems are getting the blower far enough forward to align pullies, and getting the outlet mounted so that the air charge is reasonably distributed to the runners.

Adam
 
Adam, once you get the blower in there, you'll want the rest of the SC engine as well. It just looks so dang pretty. You wouldnt believe that those who were pushing V8 on me have actually apologized saying that this is a beautiful fit!

Good luck and post some pics!

John L.

PS - note the grille V8 emblem was replaced! Just taunting those old hot rod neysayers. I expect you will get a few eyerollers from the traditionalists too. Good on ya!
 

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you should make about 3lbs of boost with that setup

ideally u want to spin the blower at 18,000

youll be fine without an intercooler, i run mine without intercoolers with no problems, i have a custom crank pulley i had cut on our cnc machine, if u search my username youll find a thread with the custom pulley, i have specifics on blower speed and what not there

Got any pics of your setup from blower to return plenum? Where do you inject the meth?
 
i could be wrong but i thought if u mount the blower upside down it wont lubricate itself

for all this hassle why not just stuff a turbo on it? less lag, more boost, better fuel economy, and sounds better
 
i could be wrong but i thought if u mount the blower upside down it wont lubricate itself

for all this hassle why not just stuff a turbo on it? less lag, more boost, better fuel economy, and sounds better

The blower will be fine. The gears will run in the oil regardless of mounting, as long as the level is correct. But you can't check the level with the drain plug on bottom.
 
Been watching all your posts about the truck John. Love it, but one electronic demon of a car at a time is enough 4 me:D I am hoping to use more of the KISS method here. I also kinda want to keep the Y-block. This is still very much at the drink beer and look/measure/brainstorm phase. IF it ever gets past that I will post up pics.

I do actually have a PAIR of turbos off new ecoboost F150, and the exhaust crosses over from driver to passenger side across the TOP FRONT of the motor in stock config:confused: Worst design EVER. But remove crossover pipe, a couple stub pipes, cap off the pass side lower rear manifold exit, plenty of room for down pipes.....I have actually held the turbos in there to eyeball mounting/routing ect. Still wanted the roots blower kinda look tho. Seems to be trading one set of design troubles for another (belt/pullies vs exhaust and plumbing). Also don't think the y-block is real well suited to boost, they don't tend to be able to handle a whole lot of compression, so keeping the #s lower is probly better.

Adam
 
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