Lycoming O290 top

John Hill

Nov 10, 2022
Gabriola Island, BC, Canada.
Hi guys. Well I am stuck. I have a set of cylinders from a G model O290 that set up very nicely at 002 over standard and had, in the face of the ridiculous price of rings and even then nobody will give me a delivery date, arranged to have the double keystone groove in the pistons cut for a strait side ring that TotalSeal had promised they could fit with a state of-the-art ring. Just before the machining was to start they informed me, well the machinest, that they couldn't fit the 4.85 bore. So, with all the Covid induced supply chain issues and lycoming effectively orphaning this model, I am once again stopped looking for parts or a modification to a solution. This engine went in various airplanes by the thousands and provided as is still providing reliable service for millions of hours and in the face of the drive to re-engine all these machines with the 320 I would love to find a reliable solution to re-ring this thing with a modification from available parts and a bit of machining to keep them safe and running. So searching for Ideas