Working on older cars and vehicles can be rather challenging. Older vehicles involve predominantly mechanical components rather than the new high technology electronic modular components that few backyard mechanics can do much with , if yours or some one else’s automobile breaks down or runs poorly. Hence the challenge of working on older vehicles. A hobbyist can actually work on them, enforce repairs and get them on the road without highly sophisticated, new car dealer or factory only highly specialized equipment, tools and assorted paraphernalia. One area that backyard as vintage auto restoration aficionados have trouble and questions with is in measuring piston ring clearance and clearances. Yet a lot of the “old timers” who worked on and with these older autos and especially engine and motor components are long gone or hard to find.
Just what are some of the former “tricks of the trade”” when working with older modern era electronic engine systems when it comes to measuring those piston rings clearances.

One method of measuring piston clearance is to use one half inch wide feeler gauge stock. It is sometimes hard to find this- yet most automotive big box stores stock good old fashioned imperial inches / feet measurement tools as well as the newer metric measurements. Such a feeler gauge of the desired width and thickness can be secured in lengths of approximately 12 inches long. The exact procedure recommended by the “masters” is to place the feeler gauge along the side of the actual piston. 90 degrees around piston from the piston ring. The piston and feeler gauge are now inserted into the cylinder bore itself. If the clearance is “correct”, the piston should push the cylinder with light pressure, but it should lock if a feeler gauge of .001 inches, more than standard clearance is used. Another method is to measure the pull required to pull the feeler gauge from between the piston and the cylinder wall. The feeler gauge should be pulled straight up and out by means of a scale. Expected readings should be in the range and ranges of between 7 and 18 lbs measurement. If less than that amount, then the clearance can be deemed to held to be too much and excessive. If less than that amount, the clearance is excessive and if more than that measurement then clearance can be said to be insufficient overall.

Still another method of measuring the piston clearance is to use micrometers. In this case the diameter of the cylinder bore is measured with inside micrometers, and the diameter of the piston is measured with outside micrometers. When measuring the cylinder bore, it is measured across the width of the engine, and the diameter of the piston is measured across the thrust faces. The difference between the two diameters will then be the piston clearance.

If the clearance is in excess of the amount specified, the pistons should be expanded sufficiently to obtain the desired clearance. This most likely will be beyond your skills and equipment at hand. It may be time to source out a local machine shop to help you finish your auto repair process on an older vehicle ready to hit the road or your vintage auto restoration project.

Author Bio: Adam I Watkins
Chilliwack Used Auto Dealers
Camrose Used Auto Dealerships
Winnipeg Truck Traders
 

Category: Automotive
Keywords: how to restore a car,auto restoration shops,backyard mechanic tips,working older auto engines