Piston ring kit Std. 3/16″ = 4.76mm Wide oil ring

Tip!

Before installing the piston rings on the piston, slide the piston rings into the cylinder bore one at a time using a plunger so that they come straight. Check that the end gap is the same on all rings. If you want to measure the end gap use a blade gauge, the Cadillac workshop manuals say there should be an end gap of at least 0.33mm. The max end gap according to Cadillac is 0.73mm, if the gap is bigger it means you get a little worse compression, if the gap is less than 0.33mm then something is wrong.

In order to get a good contact surface between the cylinder bores and the piston rings, these must be worn against each other.

The cylinder wall must be cross-honed (slightly roughened surface) when fitting new piston rings. The tops of this surface are cut down by the piston rings during run-in. In order to get a good seal between the ring and the cylinder wall, you have to create a proper cylinder pressure so that the entire circumference of the piston ring is forced out against the cylinder wall.

When you have refurbished the engine, do not let it idle. Let the engine run at a slightly higher speed for the first half hour and you will get better speed of the oil pump and water pump, thus better lubrication and cooling. Load it a little at regular intervals and you will get a higher pressure behind the piston rings and break-in will be easier.