Thread: Rocker bush assembly

Hi all,
I am trying to get my 2.25P IIa 'Dirty Mary' running again. The rocker shaft was badly worn and some rocker bushes similarly so. I have pressed in NOS bushes into the rockers and bought an NOS shaft.
The shaft is 13.9mm diameter, while the bushes once fitted have an internal diameter of 13.1 to 13.2mm.
What is the best method for reaming the bushes to size? 0.8mm difference seems a lot to me.

I figured an adjustable reamer would be the go, but talking to the chap at Hare & Forbes he was doubtful that it'd be the best tool to do the job as the bushes are split and the reamer may dig in. He suggested working up in drill sizes using a very slow pedestal drill. I doubt i'd be able to find a drill close enough in diameter to not have a sloppy fit, and trying to keep it concentric with a drill could be a problem.

Any suggestions? I don't have access to a useable lathe or mill at the moment and my pedestal drill is Bunnings quality.


Mary turns 48 on Sunday and i'd like to be able to get her engine running by then.

Has anyone come across this problem and sorted it themselves or this sort of thing best left to the professionals?