| The old piston ring was graphite yarn, it had lasted many many hours but as with most yarn rings it had lost some of its seal before it was mashed. I wouldnt use cast iron rings in a engine with a bore less than 1.5 inches. i doubt there would be any bennefit.
Delrin makes superb nuts for lite use I wouldnt want it in a cross slide i must say. Its like any material used in the correct place its superb at its job. As a lite duty bearing its hard to better it. I used to use Nylatron but after being introduced to Delrin i kept with it on most fixed bearing that have small loads.
The one big advantage with Delrin is if you get swarf or grit in the nut/ bearing it will tend to sink into the surface of the Delrin and not do too much damage to the shaft that the bearing is on.
Be warned it grows after machining! if you machine Delrin and let it sit over night it can grow a thou or so. |