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Bonnie at the Castle - Comparing Two Crankshafts

February 2023

As I was completing final engine assembly in the spring of 2022 I discovered there was a chunk of metal missing from the end of the crankshaft keyed for the rotor. Ballgame over. Crank toast.

At the end of the year I acquired a used crankshaft (ground .010" under) as well as new connecting rods from Mitch Klempf.

Bonnie's original crank was one with the lightweight flywheel, while the used crank from Klempf has the heavyweight flywheel. Photos below compare the two.

More on Flywheels:
"Flywheel"
The Bonnie Ref

(Click Photos to Enlarge)

1. Bonnie's original lightweight crank. Notice damage to shaft at location of rotor key.



2. Used heavyweight replacement crank.



3. Lightweight crank.



4. Heavyweight crank.



5. Lightweight crank.



6. Lightweight crank.



7. Lightweight and heavyweight cranks side by side.



8.



9. Number on heavy flywheel: "70-9745".



10. Marking on heavy flywheel: "RJH1".




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More Info Here
"Crankshaft"
The Bonnie Ref

See also
"Triumph Crankshaft Balancing"
The Bonnie Ref

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