Flywheel ring gears

[frequentflyer]

Were they all shrink fit or are some from parent metal? I am lightening a flywheel for our new engine in the lathe and thinking that the ring gear is a bit tired and have seen that they are available at a reasonable cost. This got me thinking if cutting across them with a hacksaw is the easiest way to remove or just turn it off in the lathe.

[AustinWood]

All originally machined from the metal. Fitted ring gears are replacements.

[Reckless Rat]

The old timer's method was to drill a hole in the face and then whack it with a cold chisel across the drilling to break it off.

[Ken Morton]

After you have turned off the original starter ring (or removed a previous replacement ) , arrange to turn down to get at least a 5 thou interference fit. warm the ring and press on . You will now have to open up the 6--   1/4 inch holes for the clutch plate (and when assembled the 1/4  inch bolts will prevent the ring from slipping)

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Apology for my previous advice. This is only valid for rear mounted starters.

[Howard Wright]

Hi 

I’m told that rather than drill these holes it is better to mill them. Less chance to drift.  I cheated and had a machine shop do mine.

Cheers

Howard

[Charles P]

And look very carefully at what you already have.
I machined the teeth off late type starter flywheel, which is a pretty brutal and jarring task, believing the teeth to be the originals. It was only some months later, after being balanced and used in competition, that the vestigial ring of the previously shrunk on replacement gear broke at a balancing hole. It made a minor clatter before expanding to fit tightly inside the bellhousing.

c

[Bob Culver]

With a crank handle a degree of tiredeness way beyond "moderns" can be risked. Shoud it occasionally miss, turning the motor 1/4 turn often allows a gear to operate

[dickie65]

I have just ordered a new ring gear from the Seven Workshop.
I am looking forward to the fun of removing the teeth on the flywheel.
I might take it into work and get most of the teeth milled off before turning it to finished size.
It will give the CNC operator a bit of a challenge, holding it down will have to be done down the centre hole.
The Big XYZ mill does a pretty good circular programme.

[Ruairidh Dunford]

Good to hear these are in stock again.

[Robert Foreman]

If you have a good lathe you can turn the teeth off in one go.