[Diy_efi] tiny injection

[The Punisher]

For Small engines I have been thinking about a centrifugal supercharger made 
from a vaccum cleaner impeller, overdriven by means of a small cog belt 
drive. The bearing support section could be a basic aluminum plate, and the 
compressor housing could be fiberglass(or CF). The whole thing could be made 
with common garage tools and a drill press. An order of magnitude simpler 
than sizing a turbo to the application.

Centrifugal blowers are realy quite simple devices(and SERIOUSLY 
OVER-PRICED). Another thing to consider is if using a carb make sure its a 
"draw through" configuration, since the small engine carbs use a low 
pressure fuel supply system. A "draw through" also lets the impeller spin 
with low drag in the high vaccum of part throttle and cruise conditions. 
Full size car centrifugals like Vortech, ATI, Paxton/NOVI and the like 
expose the compressor to full atmospheric pressure at all times and have to 
have a "bypass" system open most of the time, This wastes energy during 
normal driving(its done this way to make the kits "bolt on's").
The real problem with supercharging a small 2 stroke is determining how much 
you can boost it before youre just blowing it through the exhaust. Small 
4-strokes would be another story.

Just my $.02
Marvin Fugate


From: Brian Dessent <brian at dessent.net>
>Reply-To: diy_efi at diy-efi.org
>To: diy_efi at diy-efi.org
>Subject: Re: [Diy_efi] tiny injection
>Date: Tue, 25 Jun 2002 00:32:43 -0700
>
>Santi Udomkesmalee wrote:
>
> > I think making a turbo would be quite hard since I don't think turbines 
>that
> > small are easy to come by.  But this makes me want to design and build a
> > small belt driven supercharger.  Does anyone out there have any 
>experience
> > fabricating superchargers.  Anybody want to point me to some books?  Is
> > there any way to make a super charger without having to cut extremely
> > complex compressor wheels or blades (I unfortunatly don't have access to 
>a 6
> > axis cnc machine)
>
>In MacInnes' book _Turbochargers_ in the section on motorcycle turbos
>there is a picture of a Warner-Ishi RHB3, and the caption says it's
>suited for engines down to 0.5L.  It's pictured next to a roll of film
>for size comparison, and the compressor housing isn't much bigger than
>the film (the wastegate actuator is almost as big as the whole
>housing.)  This book is almost 20 years old, so I wouldn't be surprised
>if some manufacturer now offers a smaller model.  It's worth a shot to
>look at the catalogs or call the manufacturers.  I would sure not want
>to try to fabricate such a thing myself, the metallurgy and precision
>both seem pretty advanced.
>
>Brian
>
>_______________________________________________
>Diy_efi mailing list
>Diy_efi at diy-efi.org
>http://www.diy-efi.org/mailman/listinfo/diy_efi


_________________________________________________________________
MSN Photos is the easiest way to share and print your photos: 
http://photos.msn.com/support/worldwide.aspx


_______________________________________________
Diy_efi mailing list
Diy_efi at diy-efi.org
http://www.diy-efi.org/mailman/listinfo/diy_efi