Originally Posted by
1QwkSport2.5r
I don't understand why you would want to lap a Ringless aluminum piston to a brass liner that's gonna expand when hot. On paper it sounds nice for a quick break-in, but it also sounds like it takes life off the P/L set at the same time. I can understand doing this with the old Meehanite piston in a steel liner type of construction - those types of engines took gallons to break-in. But an ABC? I'd never allow that kind of thing in my engines. No offense.
On the flip - I'm glad I grabbed an extra piston/liner for my P3. I don't mind long break-ins and tight engines. Tight engines to me mean I'm getting my money's worth out of it.
Lapping is an option for racers to use notoriously tight engines without time consumed....it will reduce life of the piston/liner....might make the rod/crank/bearings last longer....
Having a totally round piston on a two stroke is wrong due to the piston seeing such varying temperatures in differrrent areas....you can only make the piston and liner fit together properly by bedding them im together under running conditions...
Back along there were many engines that would take a gaallon and more of fuel before they would free up.....hence the short cut for racers with more money than patience.