# Cam for the Edwards Radial 5 started.



## deere_x475guy (Nov 10, 2007)

Hey gang as promised I have some pics of the cam for the Edwards Radial 5.   This is the first part I have made for this engine.  I stated with this one because I figured it was the going to be the most difficult for me to machine.  

















The tuff part is yet to come on this.  As you can see I still need to cut the lobes.  I probably won't get back to this till after the holidays.  






I have the week of Thanksgiving off and the week of Christmas so I think I can maybe get the Webster started an completed between the two weeks off.  I am going through the plans right now so I can try to come up with the reamers I will need for it.


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## cfellows (Feb 1, 2008)

Lew Hartswick  said:
			
		

> cfellows.
> What makes the "floating piston" go up and down? Is it the pressure of which ever side is exposed,
> inlet or chamber? If so, does "blowby" cause any problem?
> ...lew...



There is a compression spring above the floating piston which holds it down as long as the inlet (poppet) valve is closed. When the poppet valve is opened by the camshaft, high pressure air pushes the floating valve up, closing off the exhaust port and admitting the high pressure air into the cylinder. 

The floating piston doesn't need to be real loose, just enough to let any high pressure air trapped in the chamber out when the poppet valve closes. The blowby doesn't really hurt anything and it actually adds a little "pop" sound when the poppet valve opens. 

The nice thing about this valve operation is, that the exhaust pathway is always open as long as the input valve is closed. this makes it easy to simulate 4 stroke, 6 stroke or hit n miss operation.


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