Difference between blower and Supercharger.

[Swamp Donkey]

What is the difference between the two. I pretty much thought they were the same thing, but am now second guessing myself. What do you know?

 

[RustyJC]

The term "blower" is generally used for 2-cycle engines which cannot pump their own scavenging and combustion air since they do not have intake and exhaust strokes. An example would be the Roots-type blower used on GM V-53 and V-71 series uniflow diesels.



A supercharger, on the other hand, increases the amount of air in each cylinder of the engine at the start of the compression stroke beyond that amount which the engine is able to pump on its own - the "super" in supercharge literally means an air charge "above atmospheric". It can be either mechanically driven (an example would be the centrifugal Paxton or the Roots-type Eaton superchargers) or exhaust driven (the turbo-supercharger [the correct engineering terminology] as used on our Cummins).



Does this help?



Rusty

 

[Joe G.]

The way I understand the terms is that blower and supercharger are the same type of thing. Engine driven at some direct multiple of engine speed by some mechanical means(belt, chain, gears, ... ). The turbo charger is exhaust gas driven and does not turn at some direct multiple of engine speed.



The first type does not have a "spool up" delay. However it takes more horses to run it.

 

[kcjayco]

I think if you look it up, a turbo is defined as an exhaust driven supercharger.

 

[Diesel Freak]

a blower moves air, positive displacement, no compression takes place.



a supercharger compresses the air



a turbo charger or centrifugal supercharger like the Paxton are not positive displacement but compress the air by "stacking it in the Volute KE to PE conversion.

 

[jwdeeming]

I've always heard blower used interchangeably with supercharger. Only distinction I ever heard of was that there are two types of superchargers: one (like the GMC models) is a box that pressurizes the fuel-air mixture, AFTER carburetion or fuel injection. The other type, like the old McCullough (sp?) my Dad raced with back in the 50's was a belt-driven air pump that pressurized the air prior to the carburetion. I suppose that might qualify as a "blower", but I don't know.



The hottest setup my Dad ever raced was a rig John Bandimere helped him build in his '55 Chevy. It was a Corvette 283 fueled by 3 Buick 2-barrel carbs - the biggest 2bbls available at the time. Then they built a housing around the six pack and pressurized that with a McCullough supercharger (blower?). Before Bandimere Speedway was built, lots of people used to race out on Alameda Avenue in Lakewood, CO, and Dad's 55 was the rig to beat for a couple of years.



JimD

 

[RustyJC]

Originally posted by Diesel Freak

a blower moves air, positive displacement, no compression takes place.

A blower is not always a positive displacement device. As an example, the Cooper-Bessemer GMVA and GMWA-series 2-cycle integral engine/compressors use a centrifugal blower gear driven off the crankshaft to pump their scavenging/combustion air. Interestingly, the GMVC and GMWC versions of these engines have a turbo-supercharger (18" diameter impeller) in series with the centrifugal blower.



Rusty

 

[RustyJC]

Originally posted by jwdeeming

I've always heard blower used interchangeably with supercharger.

That's because in the early days of drag racing Jimmy "blowers" were removed from 53 and 71 series GM diesel engines and used as "superchargers" on drag cars. This has led to the terms erroneously being used interchangeably by automotive enthusiasts.



There is a distinction between the two as I've noted - the terminology I gave is that used by engine designers and manufacturers and by associated professional organizations such as the Society of Automotive Engineers (SAE) and American Society of Mechanical Engineers (ASME). I've worked for an engine manufacturer for 28 years and use these terms daily.



Rusty