Phoenix crank

[Bob Culver]

Still curious about the roller damage. Wedging usually damages the cage and is amajor cause of collapse of rolling bearings.
What is the betting it is cracked 5:1. 10:1?

[Dave Mann]

Two of the rear rollers have grooves in them like something hard entered the bearing. Realizing that it was an original crank I advised the owner to get it checked for cracks by magnetic particle as it appeared to have a crack in the usual place. He returned it today it was cracked.

[Bob Culver]

Hi Dave
Curious as to "'usual place"'. My fluid is a bit tedious to use so start at the back and work forward and stop at the first or second crack. Limited samples, but If the rear journal has been heated usually cracked there, The presence of the rigid flywheel seems to be a factor. Otherwise either side of the first crankpin encountered.

[AllAlloyCup]

Hi Ruairidh 

You may remember when I first started my rebuilt engine with a 1 1/8th new steel crank I discovered it shaved very thin slices of ally off that Camshaft housing. I think this only happened on higher revs? Due to Whipping? I cleaned out the sump and the innards of the crankcase plus used a Dremel to relieve the camshaft casting to give a 25th clearance.

Perhaps if alloy shavings got into a bearing this might Have damaged it?

I worry that  at 25th might not be enough?

I’ve not run the engine for a bit due to house drain issues and hope to get it going again soon.

All the best
Bill G

[Ruairidh Dunford]

I do remember that happened to you Bill.

Hope you are up and running again soon.

[Dave Mann]

    This shows the mark in the top roller.

[Bob Culver]

Is it just remnant of a rust mark? 9Not the bright ring) Rollers should appear like polished chrome as when new. A matt appearance is usually associated corrosion as from short runs.

[Dave Mann]

If you look closely at the roller just to the right of center you can see a 1mm groove in it caused by a foreign body.