spoolin01
Contributor
I'm rebuilding an electric RIX SA-3 that broke the first stage connecting rod. Since it's apart, I'm replacing all the o-rings, rider rings, and compression rings in the pistons and heads, as well as the few 1st stage parts that were damaged. There was a modest amount of sooty coating on all the parts in the compression chambers, but overall there doesn't seem to be much wear on any moving parts like the cylinder walls, rod end bearings, or thrust plate surfaces.
The first stage piston is aluminum, the second is brass. My question is whether the connecting rods are supposed to be bottomed into the pistons, or whether a little play should be allowed, and torque applied to the simple locking nuts at either end. I don't want the pistons to work loose.
The manual is a little sketchy. In the section on the piston assemblies, it states 45-55 ft-lbs for the rod end bolts. Even though there is a separate manual section regarding the rod end bearings, which are fastened with 1/2-20 bolts, I'm assuming that torque figure is for those bolts. At first I took it to be referring to the connecting rod installation, but it seems too high for the 5/16 connecting rod, especially into aluminum, and the description more closely matches the rod end bearing assembly. The manual says nothing about installation of the connecting rods, or torque for those locking nuts.
The first stage piston is aluminum, the second is brass. My question is whether the connecting rods are supposed to be bottomed into the pistons, or whether a little play should be allowed, and torque applied to the simple locking nuts at either end. I don't want the pistons to work loose.
The manual is a little sketchy. In the section on the piston assemblies, it states 45-55 ft-lbs for the rod end bolts. Even though there is a separate manual section regarding the rod end bearings, which are fastened with 1/2-20 bolts, I'm assuming that torque figure is for those bolts. At first I took it to be referring to the connecting rod installation, but it seems too high for the 5/16 connecting rod, especially into aluminum, and the description more closely matches the rod end bearing assembly. The manual says nothing about installation of the connecting rods, or torque for those locking nuts.
