Running a centrifugal supercharger backwards

[TonyL]

I've devised a plan.

corvairs like mine have limited options when it comes to aftermarket induction options. there's this thing.



It makes it so you can convert the 4 little one barrels, which are hard to sinc up to a nice 4150 type holley carb.



Neat, but still, a carb. still difficult to get to work well.

But then I saw this puppy,



And I think it'll work awesome.... Especially with a supercharger hooked up to it. My car cant see loads of boost, but that's not the biggest hurdle.

My engine rotates BACKWARDS. all corvairs do. Can one modify a blower to run backward? I know it can be done with a roots type one. But this? Anyone? Bueller?

[Twentyover]

You can weld injector bungs tothe tubes adjacent to the port, to make this MPFI, rather than a TBI, and use a regular throttle body.

As far as the supercharger, can you devise a gear driven jackshaft to reverse rotation (maybe something like the cam drive gears on the Ford 2.8) Centifugals won't work backwards.Maybe a turbo may be a better bet?

[TonyL]

possibly. I've thought of running a pulley under and another one just over the top and "S"ing the belt. running the belt up against it, rather than around it, I'll have to model it.

I do have a turbo already though.... an older one, but still. Free is good. Turbo Corvairs have been done though, I want to be different.

[TonyL]

MSPaint FTW!

Will this work? Or does the belt need better contact than that?

[parsonsj]

Tony,

I've done some fab with supercharger pulleys (a loooong time ago), and we had a hell of a time with belt slippage. And we had almost 150* of belt contact. The 70* in your drawing just won't cut it. I think you need to try and get 180*, if possible.

jp

[TonyL]

i thought so. thanks!

[CarlC]

Agree with John. Mine has more than 180* and is very close to slipping.

[RSX302]

I agree with the weld in injector bungs at the head. When you get that far out, it's ugly for tuning/response. Much nicer at the head if you can get it there.

My Kenne Bell blower had a little more then 180* on the pulley with a 5 spline belt. It was only 8psig boost. Street blowers pull around 30-50hp and race versions around 100hp. God knows what a Top Fueler does....Probably the amount my Twin Turbo V8 does..

[camcojb]

Procharger makes reverse-rotation centrifugals, I had one on a Cobra replica where turning the blower backwards was the only way it would fit.

Jody

[Roadbuster]

Tony,

How about mounting the supercharger the other way around?
Mount it facing toward the back of the engine (the front of the car) instead of toward the front of the engine (back of the car). This way You don't have to change any internals or buy a custom rotating assembly and just have to fab the custom mounts which you would probably have to do anyway. The rotation is reversed and you can still get a simple pulley arrangement. The pain would be in changing the belt.

Jon

[Nessumsar]

Why not mount the super charger not on the engine, spun 180*?

Make a mount that bolts to the engine but extends out far enough to mount the charger bolted in backwards?

Like on Notorious?

[TonyL]

Sometimes the simplest solutions are the hardest ones to see. I cant believe I didn't think of just mounting the compressor itself backward! *d'oh*

[RSX302]

But then I saw this puppy,



And I think it'll work awesome.... Especially with a supercharger hooked up to it. My car cant see loads of boost, but that's not the biggest hurdle.

Check to see if they will run different MAP sensors for boost. In the instruction manual it says it comes with a 0-105kpa sensor.

[TonyL]

will do.

I've also thought about welding bungs into the manifold and just finding a throttle body that'd work. The problem is thanks to my engine's bizzare layout, firing order, reverse rotation, etc there isnt a management program in the world for it.

In the corvair world theres a HUGE demand for this type of setup. getting all 4 carbs to work is really difficult for most. I can't believe someone hasnt made a kit for us weirdos yet. They'd sell like hotcakes.

[gkring]

will do.

I've also thought about welding bungs into the manifold and just finding a throttle body that'd work. The problem is thanks to my engine's bizzare layout, firing order, reverse rotation, etc there isnt a management program in the world for it.

In the corvair world theres a HUGE demand for this type of setup. getting all 4 carbs to work is really difficult for most. I can't believe someone hasnt made a kit for us weirdos yet. They'd sell like hotcakes.

I have done a few cars using a system designed for one motor, then used on another. As long as you know the firing order the ECM is using you can just run the wires accordingly. if you are using a distributor it is real easy since you just have to run the injector wires correctly. All of the systems I have seen that are not made specifically for one car can have the firing order changed. The distributor signals are the same, it does not matter which way the motor turns. An ECm programmed to give 10 degrees advance won't give your motor 10 degrees of retard just because your motor spins the opposite direction.

[Damn True]

Centrifugal run backwards? That would suck.

[6'9"Witha69]

Centrifugal run backwards? That would suck.

[TonyL]

lol!

The weirdness that is the corvair is thus: 4 intake ports, two per head. *six cylinders* per head. Weird compression waves sharing the plenum inside the manifold/head. would most likely be a problem. Now, there's a mod out there that mills off the head, and lets you bolt on *six* runners so I'd have one injector per runner. solving that problem. But it's exorbitantly expensive.

Hence me going for the simplest carb-like answer.

[gkring]

That makes more sense. Looks like you need to stick to a throttle body injected style system. If you keep the ignition seperate (I would NOT) it would be very easy as you just need a tach signal to fire off the injectors in batch mode. it would basically be a carb, but with better control and O2 sensor feedback capability. The ignition control is a really nice gain for a supercharged application like you are planning.

[mjoc1]

The six carb intakes are not that expensive. I have seen them for $400.00 Do you belong to the CORSA.
Mike