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Rings 02/25/04

Choosing the correct ring for the application is crucial. As a professional engine builder I would consider this to be one of the most complex areas of the entire engine build and it ranks very close to choosing the correct camshaft profile, which I would categorize as being the most important. The wrong ring combination, material, and radial wall tension could either create catastrophe or can yield substantial power gains in an engine. Ring choices are application specific and to determine the correct ring package that would be right for your engine, would entail having a complete understanding of the engine you plan to build, or are building. Below is a small list of applications, and depending on the application at hand, would determine the ring choice that best is suited for that application. The right choice will yield the maximum benefits with out sacrificing mechanical reliability, it will actually increase the engines mechanical reliability. The incorrect ring combination could either contribute to excessive drag which would produce additional load on the reciprocating assembly, and additional load could cause an engine to prematurely fail do to excessive cylinder wall heat, heat absorbtion in the pistons, and stress on the lower end. These Olds engines are temperamental when using factory crankshafts and the ring choice is crucial. Too loose of a radial wall tension ring, especially in the oil ring rails and its expander, could cause oil contamination in the chamber, detonation and oiling out that exhaust port will occur. Oiling an exhaust port will hurt exhaust flow. A bore is a bore is a bore, and choosing that correct package takes many years of understanding on what works and what does not. Have a professional engine builder help you with your choice of rings for your application. Have a professional engine builder help you design the piston so that it can accommodate the correct ring package for your application. There are substantial gains in HP, torque, longevity and mechanical reliability when it comes to the correct ring choice. Gains of over 25 to 30 hp can be found when using the correct ring package. 80 percent of an engines power is lost in the reciprocating assembly and by making the correct choices you can limit your hp losses. The myth, a lighter ring package will not last as long as a heavier one. This is completely untrue. The lighter ring packages will out last, out perform and be mechanically better for the application than a conventional heavy weight ring package. The key is understanding how light you can go, and most engine builders do not have a clue, so they use standard tension rings with the motto, better be safe than sorry. Again too much tension can create mechanical failure and premature engine life expectancy. How do you measure or know what ring is correct or incorrect? This is the art form, it is by feel and it is almost impossible to explain. Over the years and in working with many bores and many different applications, I learned exactly what package would work the best for a given bore size and application, again, one of the most complex items to understand in engine building. I can guarantee you this, and that is, if you can purchase a ring package through a mail order house chances are is that it will be incorrect for your application, not in bore size but in radial wall tension. Be very cautious, there are many ring companies that box there rings and classify them incorrectly. Buyer beware. Here is a list of just a few applications, normally aspirated no vacuum pump bores 4.0 to 4.280, normally aspirated vacuum pump 4.0 to 4.280, normally aspirated dry sump 4.0 to 4.280, The same as above with bores 4.350 – 4.500, the same as above with 4.560-4.700, the same as above with bores greater than 4.700. The same as above with aluminum blocks vs. iron blocks. Injected alky. Blown injected alky. Turbocharged. Nitrous Oxide. All different applications that would determine different styles of rings, radial wall tensions, and bore finishes. To some this will help, to others this will be confusing. No one said engine building is easy and learned over night. I have over 21 years in doing this and you learn something new every day.