Working on older vehicles – especially older Chevrolets “Chevies” is a labor of love for many backyard mechanics. These automobiles and their mechanical components were just so “American”. They were built rugged “like a Chevy” and easy to work on and repair. Its simple mechanical components in a generally open fashion. Easy and fun to work on – not these modern cramped, electronic ridden contraptions that we have today in 2011. One simple routine that is often asked is “How do we fit piston rings” (properly).

No doubt that it is a good thing for auto owners and those wishing to overhaul engines that replacement type piston rings are designed to compensate for a certain amount of wear in the cylinders. It can be said that the claims that were made by some manufacturers were somewhat extreme, but in general replacement type rings should not be installed into cylinders that have more than .01 inch taper or .005 inches out-of-round.

When selecting a piston ring set for an engine, it is necessary to select its proper size. To do this, position the ring in the cylinder bore in which it is going to be used. Push the ring down in its bore area where normal ring wear is encountered. Use the head of a piston, to position the ring in the bore so that the ring itself is square within the cylinder wall. Be careful to avoid damage to the ring or cylinder bore.

Measure the gap between the ends of the ring with a feeler gauge. The size of the gap is dependent on the make of the piston ring and also on the diameter of the cylinder bore. In general this gap should be .003 inches for each inch of diameter. In other words the correct ring gap for a 3 in bore cylinder should be three times .003 inches or .009 inches.

The slide clearance of the piston rings in the groove should not be less than .001 inches for both oil and compression rings.

Piston rings are easily installed on the pistons. Some mechanics use special ring spreader tools, which of course make the installation quite simple and without any danger of breaking the ring. Other mechanics will use a special tool but will spread the rings by hand. On the cast iron type rings, the procedure is to place a thumb over each end of a ring and spread the end of the ring apart. This will enlarge the diameter sufficiently so that it can be slid down over the piston to its proper groove. Be careful to follow the manufacturer’s instructions so each ring is placed in the correct groove. In some designs it is necessary that one sing of the ring be toward the top of the piston, if rings are not placed in the proper groove and with the right side up, excessive oil consumption will result.

Lastly when placing piston rings on the pistons they make sure that the gaps and gapping is correct. In this way the ring gaps are not in a row. As a result and consequently, blow-by through the gaps is kept to a minimum.

Author Bio: Ted I Boatman Wpg Auto Auto Sales Vancouver BC Canada Car Information