Antique Tractors Forum

[jdcrawler]

Here are the three cams that I've ended up with so far.
The cam on the right is my original cam without a governor.
It has a mechanical advance for the ignition points on the end of the camshaft.

The cam on the left is the one I got from a member and the cam in the center is the new one I got today.

Notice that my old cam has a narrow cam bearing area with the points lobe on the end.
The cam on the left has a wider cam bearing area with the points lobe on the end.
That is why this cam did not work.
When I installed it, the hole for the points plunger opened up on the cam bearing surface and not the lobe surface.

The cam in the center has the narrow cam bearing area with the points lobe on the end just like my old cam.
When I installed it and rotated the engine crankshaft the points plunger moves down and up like it should.

..... NOTE .....
The cams are setting with the points lobe up.
The cam lobes on my old cam are pointing to the left and the cam lobes on the new cam ( center cam ) are pointing to the right.
With the points lobe up, the two cams are 180 degrees off from each other.
The timing mark on the front of the gears are also 180 degrees off.

If I set the cams so the timing mark on each is at the same position, then the cam lobes are the same and the points lobes are 180 degrees off between the two cams.

What is this telling me ???????
Does that just mean that instead of firing left side and then right side, it will now fire right side and then left side ?

....... I put a test light on the points.
They close just as one piston starts coming up on the compression stroke and open up when that piston reaches about 20 degrees BTDC.
Then it does the same on the other side so I guess it's working OK.





Anyhow ... the engine is torn down so I can change the cam.




Here is the workings of the governor on the cam.
It has all these steel balls the are held in the pockets on the front of the cam.




There is a cone shaped plate that fits over the balls.
As the cam spins, the balls are thrown to the outside by the centrifugal force.
This forces the front plate to move out away from the cam.




The front cover has a rod with a forked tab that rides against the plate on the cam.
As that cam plate moves it makes the rod move.
At the top of this rod is a lever that ha a a linkage rod attached to the throttle on the carb.




The new cam is installed and I lined up the timing mark with the timing mark on the crankshaft.
That's as far as I got today.


_________________
Ray
..........................................................................
1945 John Deere Lindeman crawler ( modified )
1949 Agricat crawler
1948 Bolens Ridemaster
1953 Bolens Ridemaster
1959 Chevy 1-Ton truck

[Grizz]

Dumb question time .
Is the cam gear perminantly attached to the cam or can it be changed, IE one of the governored gears onto your origonal cam (you probably already though of this but I had to ask)
_________________
1958 JD 820
A fleet of JD 96 combines
1988 379exhd Pete 3406 CAT
Pettibone super 20
A bunch of other junk

[kiwi071]

Looking good Ray,back to putting it all back together (again) be good to see
it outside running
_________________
kiwicolin

[jdcrawler]

[jdcrawler]

Along with the cam and governor, I got the correct carburetor for the engine ( the other one was off a B&S V-twin )

The carb is mounted and sets right down on the manifold with out having to use any adapter for it to clear the points box.
I had to modify the lever arm for the governor so it would clear the bracket for the alternator.
This is the linkage position at idle.




And the linkage position at full throttle.




The throttle cable should still work out OK on this setup because it will still come in from the side of the engine.
I may have to make some sort of 90 degree bracket for the choke as that cable comes in from the front of the engine right now.

I'm waiting on head gaskets to arrive and then I can set this back into the tractor frame.
_________________
Ray
..........................................................................
1945 John Deere Lindeman crawler ( modified )
1949 Agricat crawler
1948 Bolens Ridemaster
1953 Bolens Ridemaster
1959 Chevy 1-Ton truck

[jdcrawler]

At last .. the engine is setting back on the frame !
Hopefully I can still get this tractor finished in time for the Buckley show in August.


_________________
Ray
..........................................................................
1945 John Deere Lindeman crawler ( modified )
1949 Agricat crawler
1948 Bolens Ridemaster
1953 Bolens Ridemaster
1959 Chevy 1-Ton truck