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- Jul 16, 2007
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Gentlemen,
I have been following the O ring discussion in another thread and have read several others in the past. Most of the builders on this forum have been machining and making engines for quite some time. That being said I have trouble understanding why there is such an aversion to making actual piston rings. If one follows the discussions about O ring use there seems to be more negatives than positives in their use. It seems everyone has their own guidelines for using them, type, O ring, X ring, material, Viton, neoprene, piston fit, loose, tight, cylinder wall fit, tight versus loose. When using piston rings there are hard numbers and data for their use. I feel that using O rings is taking the easy way out. Granted for a novice builder who would just like to build his first engine and hear it run I understand their thoughts but for the rest of us that have two or more engines under our belt I don't understand the aversion to making and using piston rings. Having built many engines over the years and following other's builds the biggest challenge in getting an engine running, bar none, is getting the valves to seat and seal properly. Hours can be spent machining the valves, seat cutting, lapping and pressure testing but yet we all accomplish this task one way or another. In building an engine there's so many somewhat complicated parts that need to be made, gears, cams, valves and crankshafts to name but a few and yet here again we are all able to do this but mention the word piston ring and some people get cold chills. To me making rings is one of the easier machining exercises connected with building an engine. You turn a piece of iron (very easy to machine) to a given I.D. and O.D. You then part it off to a given thickness. You break the edges then split the ring. If using the Trimble method a fixture needs to be made for heat treating. This is just another simple machining project. Now the heat treating. I don't have a kiln or heat treating furnace, I just use a standard propane torch. When making my fixture I hollow out the bottom so when heating there's not a lot of mass to heat up. Long ago i purchased a jar of Boron powder from a gun supply shop and after multitudes of piston rings I still have enough to last my engine building career. The rings are mounted on the fixture. The fixture is heated up then coated with the powder. The powder turns to a somewhat liquid coating much like silver solder flux. I then place the flame of the torch into the pocket in the bottom of the fixture so that I'm not applying the heat directly on the rings. I then hold the torch until the whole fixture and rings are brought up to a dull red color and once obtained hold it there for 2-3 minutes. The fixture is then allowed to cool and then the Boron coating is washed of with tap water. The rings are then unmounted, cleaned. fitted to the bore and gapped. Trimbles method and several other can be found on the internet for free and give a more thorough explanation in the making of piston rings.
To sum up my dissertation, why not give piston rings a try. It's really not that hard of a job and then you don't have to worry about all the issues of fitting and using O rings.
gbritnell
I have been following the O ring discussion in another thread and have read several others in the past. Most of the builders on this forum have been machining and making engines for quite some time. That being said I have trouble understanding why there is such an aversion to making actual piston rings. If one follows the discussions about O ring use there seems to be more negatives than positives in their use. It seems everyone has their own guidelines for using them, type, O ring, X ring, material, Viton, neoprene, piston fit, loose, tight, cylinder wall fit, tight versus loose. When using piston rings there are hard numbers and data for their use. I feel that using O rings is taking the easy way out. Granted for a novice builder who would just like to build his first engine and hear it run I understand their thoughts but for the rest of us that have two or more engines under our belt I don't understand the aversion to making and using piston rings. Having built many engines over the years and following other's builds the biggest challenge in getting an engine running, bar none, is getting the valves to seat and seal properly. Hours can be spent machining the valves, seat cutting, lapping and pressure testing but yet we all accomplish this task one way or another. In building an engine there's so many somewhat complicated parts that need to be made, gears, cams, valves and crankshafts to name but a few and yet here again we are all able to do this but mention the word piston ring and some people get cold chills. To me making rings is one of the easier machining exercises connected with building an engine. You turn a piece of iron (very easy to machine) to a given I.D. and O.D. You then part it off to a given thickness. You break the edges then split the ring. If using the Trimble method a fixture needs to be made for heat treating. This is just another simple machining project. Now the heat treating. I don't have a kiln or heat treating furnace, I just use a standard propane torch. When making my fixture I hollow out the bottom so when heating there's not a lot of mass to heat up. Long ago i purchased a jar of Boron powder from a gun supply shop and after multitudes of piston rings I still have enough to last my engine building career. The rings are mounted on the fixture. The fixture is heated up then coated with the powder. The powder turns to a somewhat liquid coating much like silver solder flux. I then place the flame of the torch into the pocket in the bottom of the fixture so that I'm not applying the heat directly on the rings. I then hold the torch until the whole fixture and rings are brought up to a dull red color and once obtained hold it there for 2-3 minutes. The fixture is then allowed to cool and then the Boron coating is washed of with tap water. The rings are then unmounted, cleaned. fitted to the bore and gapped. Trimbles method and several other can be found on the internet for free and give a more thorough explanation in the making of piston rings.
To sum up my dissertation, why not give piston rings a try. It's really not that hard of a job and then you don't have to worry about all the issues of fitting and using O rings.
gbritnell