Reply To: 1956 Johnson 15HP Rod bearing clearance

[Don]

Hmmm, I dunno…. You may be looking for problems that aren’t really problems. These engines were never designed with real tight tolerances to begin with. I hear you saying that the excess clearance is on the wrist pin end, am I understanding you correctly? The big ends of the rods surely seem to “look” fine as do the crank journals. Mumbles has surely had great success pressing in new bearings on these rods, but you have to be sure there is no slop between the wrist pin and its corresponding bore in the piston as well.
Just wondering if this engine could be “updated” to use the 57 rods and wrist pin roller bearings?? Just a though, no idea if it can be done though.