# Hodgson 9 Cylinder Radial Aircraft Engine



## pelicanparts (Oct 3, 2012)

Hodgson
9-cylinder Radial engine. It has a 24 inch prop. It has a 1 inch bore, 1 & 1/8 inch stroke, and
is 7.95 cubic inches. Built by well-regarded enthusiast Bob Haageson of Pomona, California. Acquired by Wayne R. Dempsey of Pelican Parts Inc. for his collection in 2012.


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## Bentwings (Jun 25, 2020)

Lots of nice builds on the site. I’m an ex hotrodder dating back to early fuel dragster and later funny cars.
if you wanted performance it had to be supercharged and today it’s all about turbo charged.  So has there been any work done on blowers or super charging the radials. Conley has a scale spurt charger that really works. It would seem that both the inline and radials would benefit by some air mover. I don’t know how much vacuum or sbsolute pressure is in these motors but some form of air mover I’m sure would make them easier to operate. Just because there is a more positive movement of air and fuel mixture in the manifolds.

having given some thought to this it’s apparent that the drive system is very confining. Possibly an electric model motor could drive a blower for the short time these motors are usually operated. You could even add the battery charger for a longer run time.  Making a scrol or lobed rotor blower would be challenging as mr conley found. I’m sure most know of cnc shops that could machine parts and now with 3D metal printing coming of age I think there are possibilities .  Once I get into my project a ways I’ll get to looking at reality more.  The positive displacement diesel 6-71 blowers have come a long ways from their beginnings. The technology can be used but you are still attempting to push a relatively small piece of air with a ver small mover. It doesn’t scale well at all so it mostly a matter of improving volumetric efficiency with a very small size wise device.its hard enough to just get a small shop air compressor to put out 120 psi takes forever to fill the tank. Imagine what it would be like with a 1/4 scale compressor.


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## William May (Dec 13, 2021)

Bentwings said:


> Lots of nice builds on the site. I’m an ex hotrodder dating back to early fuel dragster and later funny cars.
> if you wanted performance it had to be supercharged and today it’s all about turbo charged.  So has there been any work done on blowers or super charging the radials. Conley has a scale spurt charger that really works. It would seem that both the inline and radials would benefit by some air mover. I don’t know how much vacuum or sbsolute pressure is in these motors but some form of air mover I’m sure would make them easier to operate. Just because there is a more positive movement of air and fuel mixture in the manifolds.
> 
> having given some thought to this it’s apparent that the drive system is very confining. Possibly an electric model motor could drive a blower for the short time these motors are usually operated. You could even add the battery charger for a longer run time.  Making a scrol or lobed rotor blower would be challenging as mr conley found. I’m sure most know of cnc shops that could machine parts and now with 3D metal printing coming of age I think there are possibilities .  Once I get into my project a ways I’ll get to looking at reality more.  The positive displacement diesel 6-71 blowers have come a long ways from their beginnings. The technology can be used but you are still attempting to push a relatively small piece of air with a ver small mover. It doesn’t scale well at all so it mostly a matter of improving volumetric efficiency with a very small size wise device.its hard enough to just get a small shop air compressor to put out 120 psi takes forever to fill the tank. Imagine what it would be like with a 1/4 scale compressor.



The Hodgson engine has a built-in blower in the rear case, between the carb inlet and the fuel distribution tubes that lead to the cylinders.


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## Bentwings (Dec 13, 2021)

I thought about expanding this to two of them , one being given over drive to provide mor air to the original blower . Something thi small is hard to get much air moving. There have been a number of attempts to do this on YouTube but I haven’t seen much that worked. a well done positive displacement supercharger would be better I think but drive speed is hard to do efficiently in this size. 
byron


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