Eagle Upgrade

[rdean]

Two years ago I built a Bob Shores Eagle engine this is it when it was competed in 2020.
It has been very reliable and gets ran ever month or so as do all my models.


I have made some minor changes over the time like a see through gas tank and battery upgrades but basically it is just the way it was then.
I made a flying ball governor for my engine called "Red" last month and with that built and new governor I was able to get the slow speed down to 480rpms. Now the Eagle is a solid engine but because of the way it is built it is not a slow runner. At last check it likes to run at 1200 to 1400rpms so why not make a new governor for it and see if I can slow it down.

The Eagle is a much smaller engine so the governor will have to be smaller, a lot smaller actually about 1/4 the size.
I started with a block of aluminum, some 3/16" shaft and some 0.560 brass stock.
The miter gears are 0.560 in diameter with 18 teeth and cut with Mod 0.7 gear cutter.


I made a couple of extra gears just in case they are needed later.
There isn't much room on the Eagle so the gear case was a job in itself with lots of cutting and fitting and thinking.


I had forgotten how much I hated these little parts as my fingers don't work as well as they used to.
In order for the driven pulley to line up with the crankshaft it has to fit over the gear box housing.


This shows how the pulley was hollowed out on the inside to fit over the gear box.

More later

Thanks for looking
Ray

 

[rdean]

More little fidelity things made. I spent a lot of time looking for them on the floor but all were found.
The shafts are threaded 4mm and screw into the balls.
Have you ever tried to drill a hole in a round ball?
It just won't sit still !


A couple of pictures with it put together and mounted.
You can see now how the pulley goes over the frame of the governor.

There is only .035 clearance between the pulley and the flywheel.


Next will be the hit-miss plunger assembly on the near side rail.

Thanks for looking
Ray

 

[Chris Hamel]

Looks good. Will be interesting to see if it changes how the engine performs.

 

[rdean]

Just 4 major parts left to make and they have taken more than a day to accomplish. The first is the bracket that holds the actuator rod that catches and holds the valve lifter until the engine slows down. Very labor intensive with multiply angles and slots and that little piece is done.



This shows where and how it is mounted. It is also adjustable front to rear so it just catches the lifter.



The next piece is the rocker arm bracket that is mounted on the engine block. The rocker arm pivots on this bracket and pushes the actuator rod down.
Next is the rocker arm itself that is 2" long with a pivot hole in the center. One end is drilled for a 0.090 steel pin to be pressed into bar and that pin rides in the lower groove of the spool.
And finally the actuator rod is drilled and taped 4-40 for a adjusting screw and then cut to length. It also has a small spring on it to lift the rod up when the engine slows down.
I didn't take any individual pictures but I do have a couple of the parts installed on the engine.





I did start the engine and it ran fine but not any slower. The governor worked flawlessly so on to the next part of the upgrade.
From past experience I knew the flywheels were not designed for slow running. They are 3 1/2" in diameter and weigh 25oz but the new flywheels will be 5" in diameter and weigh 30oz.



The weight is not as important as the diameter and I know what the increase of diameter greatly increases the inertia of a flywheel.
I will be installing two of these 5" wheels in the coming days.

Thanks for looking
Ray

 

[Chris Hamel]

Glad to hear the governor worked smooth.

 

[rdean]

I just hit a HOME RUN and here is the video to prove it.

I was not expecting this great of a rpm reduction from this little engine but it all worked out just right.
The slowest I saw was 480 rpms with a high of around 900.
It does fire multiple times to get those big flywheels turning but then coasts for up to 5 seconds.
I couldn't be happier and now some still pictures.

Side view showing the 5" flywheels.


I removed the spring in the governor mast so the balls are free to move where they will.


Hit-Miss linkage.
I removed some of the coils off this spring as well.


Front View


Side view showing the other side.


From the rear.



Closeup view from the rear.

Thanks for looking
Ray

 

[Chris Hamel]

Sounds good. Those are some big flywheels.