Editing Blowers

THIS ARTICLE WILL LOOK A LITTLE GOOFY FOR A WHILE, UNTIL I GET EVERYTHING SORTED OUT.....

I had an article on blowers on another forum that got over 2,500 hits in a little over 2 years. Then, when they did an update on the forum, they lost all the information. I plan to research and do it again here real soon.
techinspector1

I'll be investigating and reporting on these and any others I can find......
http://www.roadsters.com/engines/#Blowers

First of all, why a blower? What good is it?
By increasing the pressure of the intake charge, you push more air into the cylinder. More air, when mixed with more fuel, makes for a stronger combustion burn. The stronger burn pushes harder on the piston, which pushes harder on the crankshaft, which creates more torque/hp. This article will only address mechanically-driven blowers or superchargers. Turbochargers will be covered later in another article, probably by someone else, because although I know they work very well, I just can't get wrapped around the maps used to size them. Maybe later.....

This will get us off to a good start....
http://www.superchargeronline.com/content.asp?id=15
http://www.superchargersonline.com/content.asp?id=16
http://www.superchargersonline.com/content.asp?id=31
http://www.superchargersonline.com/content.asp?ID=76
http://www.superchargersonline.com/content.asp?id=85

There are SEVERAL types of blowers; Roots, Screw and Centrifugal to name the most popular today. In the past there have also been sliding vane (Judson) and axial flow (Latham)units, piston type (like the unit on the top of your air compressor) and probably some other types I've never heard of.  Let's look at each one and list some sites for finding them......

ROOTS TYPE....
These blowers were never designed to compress air, just to move air from one place to another, sort of like your house fan. No internal compression takes place in the blower, but the restriction of the closed intake valves in your motor allow the buildup of pressure in the intake manifold and head ports. The centrifugal and screw type blowers make pressure inside the blower. 
There are Roots designs which have 2 lobes on each rotor and others with 3 lobes on each rotor. There are also variations where the rotors are "twisted" into a helix along their axis to help prevent the "backwash" of air between the rotors and reduce "buffeting".  
http://en.wikipedia.org/wiki/Roots_blower
A neat animation showing a straight-on view of the rotors in a 3-lobe Roots. Air entering is in blue and air exiting is in red....
http://www.mekanizmalar.com/roots3.html
The Roots types we are most familiar with came as original equipment on GMC two-stroke diesel engines. The number of cylinders and the cubic inches per cylinder is the way the engines were designated, so the blowers just naturally were called by the same designation. For instance, a 4-71