MINI GROOVES AND ACCUMULATOR GROOVES EXPLAINED Piston ring second land accumulator grooves provide an area for escaping combustion gases and crankcase pressures, that get past the piston rings, to gather and dissipate. Without this feature, the passing compression...

Piston Ring Squaring Tool I made a quick and accurate piston ring aligner for checking end gaps out of a .030 over, 454 Chevy flat top piston. Just chuck the piston in a lathe and turn the ring lands down to a little under 4.000 ̋. (Mine is 3.995 ̋.) The bottom of the...

PLASTIC PISTON PACKER I recycle the thick plastic trays used to store and ship 1-liter soda bottles. They work really well for keeping piston and rod assemblies in order, and protected from damage as you move them about the shop. Trays are very stable when you set...

Evolution of Ring End Gap Theory It’s easy to see or know when you don’t have enough ring end gap. Common signs include scuffed ring faces, damaged rings and cylinders and/or shiny areas on the butt ends of the rings. The ideal minimum ring end-gap would by found...

SQUARE RINGS IN A ROUND HOLE We have a quick trick to use while checking ring gaps on odd engines that you may not have a ring squaring tool for, and/ or the pistons are not of a flat top design. Set your digital-dial calipers for the depth you want to check the...

CHANGES IN PISTON DESIGN Last month we discussed changes in piston ring design. Changes in rings also mean changes in the pistons they ride on. A century ago you could find cast iron pistons in your motor. Aluminum soon proved to be a lighter weight and more durable...