09-05-2021, 12:50 PM
(07-02-2018, 11:57 PM)GK5268 Wrote: The piston ring gaps should all be staggered and they need to be correctly gapped...
Many years ago I knew one Maurice Patey, a long-time Scott aficionado and an ex-Rolls Royce engineer who, among many other things, had worked on the development of tank engines. He told me that, curious to find out if it made any difference, in 1941 they checked to see if anyone in the department had experimented with lining up ring gaps. As nobody had, they assembled an engine in this way, ran it on the testbed for a couple of hours and carefully measured the power output, fuel and oil consumption, etc. The engine was dismantled with the intention of staggering the ring gaps to see if it would make any difference. There was no need, the rings had had already done it themselves.
On Ruairidh's point about the rings being the right way up, in the 1970s a friend bought a new Yamaha TZ350 racing motorcycle. Being of the rather thorough kind - and having a fully-equipped toolroom to hand - stripped the bike to its components parts to check tolerances and the quality of assembly. He could find only one thing wrong - the piston rings were upside down.