Q: My Piper Colt PA-22-108, has a C1B installed. I have a little rust in the cylinders in the lower part. From the middle part and up to the top of the piston area there are no cracks or visible rust. I have honed all cylinders and there are no sharp edges.
GUNNAR HEGSTAD, Norway
A: It’s nice to hear from Norway and, from my past experience, hearing about rust and corrosion in cylinders in that part of the world is not unusual. I believe most of these conditions come about from extended periods of inactivity, especially during the winter months when the weather prevents frequent flying.
My main concern regarding the rust situation is whether there was any deep pitting on the cylinder walls. Normally, if only slight surface rust is found, a good honing may serve to enable the cylinders being returned to service.
I strongly recommend you review Lycoming Service Instruction 1047B Reference #2 with regard to proper honing procedures. Even though this addresses the subject of honing nitride cylinders, the same procedure must be used when honing any cylinder.
The method used in this procedure is very important and any deviation from the procedure may result in high oil consumption. Also, anytime cylinders are honed, you must install new piston rings.
One more important thing to remember now that you’ve honed your cylinders and installed new piston rings: You should break the engine in according to Lycoming Service Instruction 1427C for the best results in seating the piston rings to the freshly honed cylinders. This is a very important step to assure proper break-in and avoid the possibility of high oil consumption.