Supercharger info

[Clive Apps Techno-Logicals 416 510 0020]

> 
> >This is going on a Fiat 850 sport (903cc engine), since I have no idea how
> >many
> >hp this combination will produce, how do you work the fuel calculations ?  The
> >ones I've seen all require a knowledge of desired hp (well, I know what I
> >desire but I can safely say that it will be unachievable).  So where do you
> >begin when superchargers get involved ?
> >
> Me too. I'v got an IH Cub tractor (60 CID flathead 4 banger) which has been
> crying for a supercharger so that it can even be able to move itself and
> turn a belly-mower at 7250 feet MSL. I've been looking for a blower for it
> for a while from an economical source (read cheap). More info on this Ota
> unit would be welcome.

this unit should be about the right size to produce your 30 lbs of boost
on your ~1l engine
 
there are positive diplacement and VE does not vary widely with speed
once the unit is in it's range 
until you over speed and make heat, or drop speed and leak pressure
you will have to pseed it up to about 1.5-1.7x crank top get the PR you want

Clive 

> What you have to watch with positive disp. blowers is that their volumetric
> efficiency AND their adiabatic efficiency both drop precipitously if you
> slow them down too much. My calcs for the Cub indicate that I will need a
> blower unit which only displaces about .2 to .25 liters/rev in order to get
> the blower speed up to where it would be reasonably efficient.
> 
> Your 850 Fix It Again-a-Tony will probably turn about 3 (or more) times
> faster than the Cub, although I doubt that you will want quite the pressure
> ratio that I want to go for (2.8:1). Therefore, you could probably use a
> unit with 20-30% more disp/rev than I can without trouble.
> Keep in touch. My sweetie wants our meadow mowed.
>                                         Regards, Greg
> 
>