connecting rod wear & side play
Posted: Sun Dec 26, 2021 7:00 am
Dear All,
while waiting for warmer weather to continue the finetuning of my 59 engine, I am preparing parts for the next projects -- currently I want to assemble two crank sets and I came up with a very general question.
I know that the connecting rod play is measured in different ways and that the main point of interest is the radial play, hence the wear of the rollers and races. Still, there are values for "pure" side play of the rods, measured with a feeler gauge. So here is my question:
The tolerances specified is for the side play, not the connecting rod width -- the flywheel washer are available in different variants (with/without recess) and thicknesses. Is there a minimum width of the lower female rod or is only the side play relevant and should be set with thicker washers? (Of course the width must be wide enough, that the rollers run fully in the races). That beeing asked, what happens if the width of the female rod is not equal (e.g. one side 0.02" smaller than the other side)?
I know, that a connecting rod is not that expensive and that I shouldn´t mess around with the bottom end. But having an almost perfect (still in its original assembly) set of KH flywheels, besides the reduced width of 1.46" of the female rod and the option to have the side faces grinded perfectly parallel and rectangular to the rollers, I am considering to re-use these rods with thicker flywheel washers ...
A friend of mine, a quite experianced engine builder (Indian, Flatheads, Knuckleheads) mentioned, he wouldn´t worry to use the rods with thicker washers -- still, not an expert with Ks and Ironheads, I hope for the well educated feedback from this group!
Have a nice "rest-christmas", and thanks in advance
Ralf
while waiting for warmer weather to continue the finetuning of my 59 engine, I am preparing parts for the next projects -- currently I want to assemble two crank sets and I came up with a very general question.
I know that the connecting rod play is measured in different ways and that the main point of interest is the radial play, hence the wear of the rollers and races. Still, there are values for "pure" side play of the rods, measured with a feeler gauge. So here is my question:
The tolerances specified is for the side play, not the connecting rod width -- the flywheel washer are available in different variants (with/without recess) and thicknesses. Is there a minimum width of the lower female rod or is only the side play relevant and should be set with thicker washers? (Of course the width must be wide enough, that the rollers run fully in the races). That beeing asked, what happens if the width of the female rod is not equal (e.g. one side 0.02" smaller than the other side)?
I know, that a connecting rod is not that expensive and that I shouldn´t mess around with the bottom end. But having an almost perfect (still in its original assembly) set of KH flywheels, besides the reduced width of 1.46" of the female rod and the option to have the side faces grinded perfectly parallel and rectangular to the rollers, I am considering to re-use these rods with thicker flywheel washers ...
A friend of mine, a quite experianced engine builder (Indian, Flatheads, Knuckleheads) mentioned, he wouldn´t worry to use the rods with thicker washers -- still, not an expert with Ks and Ironheads, I hope for the well educated feedback from this group!
Have a nice "rest-christmas", and thanks in advance
Ralf