Attention: TDR Forum Junkies Continuation from "How to PROPERLY break in a diesel engine. Part 1"
Once the rings and cylinder have "mated," they will have worn away a considerable amount of their roughness. They will wear slower than they did when they were new. This reduced wear rate indicates the end of break-in, and a decrease in oil consumption should be obvious to the owner / operator. Furthermore, blow-by and fuel dilution should also be reduced but may not be so obviously evident. Be aware that engines employing Plasma faced ring technology will take a longer time to break-in. These rings tend to wear far slower than chromium-plated rings. The plasma ring’s hardness allows it to wear the cylinder wall in a more aggressive manner while only polishing the ring surface. Eventually the cylinder wall wears to the shape of the ring and subsequent cylinder wear evolves to a polishing process. This extended process drastically improves the sealing potential of the cylinder, which will correspondingly reduce blow-by and the amount of physical wear on these components. Therefore, we can safely say that the plasma faced ring / Ni Resist insert combination greatly extends engine life. Unfortunately, the price of this better seal is a longer break-in period.
So the big question is: How long does it take for an engine to break-in? Outside of the rings being hard as rocks and just taking their own sweet time to mate to the cylinder bores, the greatest factor is how the engine is broken-in. Most engines will be broken-in after running for some time, but some ways of breaking-in an engine are far superior to others as they are more likely to produce low blow-by and near zero oil consumption.
Therefore, I will lay out some recommended DOs well as definite DON’Ts:
1. DON'T run the engine hard for the first 50 to 100 miles. It is recommended that the engine be operated around the torque peak (1500 to 1800 RPM) in high gear. This loads the engine very gently, and allows the internal parts to "get acquainted" without any extreme forces.
2. DON'T let the engine idle for more than five (5) minutes at any one time during the first 100 miles. (Even in traffic. ) Remember those loose fitting rings, and possible fuel-oil dilution that were noted above? (Fuel Dilution is very common when diesels idle, even with well broken-in engines. ) Well, if that fuel is allowed to contact the main and rod bearings during break in (not really good at any time), you might be looking at an engine that will always consume some oil and one that may not produce power or mileage as expected. In the first few miles of break-in, the bearings are mating to the crank, rods, etc. It is imperative during this time that the lubrication qualities of the oil remain robust. Fuel in the oil will reduce its ability to absorb shock and float the rotating parts in their bearings. Contact between bearings and journals will occur more frequently which will result in additional friction wear. This will ultimately reduce the tight tolerances between the bearings and journals. What was originally a tight fit will be sloppy and will never be able to mate properly.
3. DO drive the engine at varying RPMs and speeds until about 1000 miles. The idea is to alternately heat and cool the rings under varying RPMs. Manual transmission-equipped trucks are the best for this as they typically employ engine compression to slow the vehicle during normal operation, this constantly allows for varied RPMs. This can also be done with automatic transmissions, but it requires that you manually downshift the transmission into the lower gears while driving. Typically, most people with automatic transmissions operate their vehicles in Drive or Overdrive gear positions without making these manual shifts. When their vehicle is decelerating and the speed falls below 38 mph the transmission has little influence on engine RPM. This is because the torque converter unlocks and the auto transmission does not downshift to lower gears in the same fashion that manually shifting does. My suggestion to those with auto transmissions is to find an empty parking lot in the evening, and drive back and forth across it in the lower gears. (This can be done with standard transmission trucks as well. ) Each time revving her up close to redline and letting engine compression slow it back down. This gets the rings a bit hot, but the compression braking allows the pistons to cool with high oil spray flow and no fuel load. Keep doing this for a number of runs, or until boredom sets in.
4. DO put a load on the engine at around 1000 miles, and get the thing hot! Diesels are designed to work, and in many cases, they operate best under a load. Baptize your engine with a nice "initiation load," to introduce it to hard work. Keep the revs up (but watch the EGTs), and make sure the coolant temps rise. Hooking up your trailer and finding some hills to pull works great for this. After the 1000 mile pull, just drive it normally, always making sure to let the engine get up to normal operating temps (no 1-mile trips to 7-Eleven). Towing is ok but remember to not overload and to monitor your gauges carefully erring on the side of caution. Under these conditions, I have seen most diesels completely break-in between 10-15,000 miles, and have always been able to tell that point from mileage gains. One may also notice that the "symphony" of the engine also changes slightly at this point.
We know that Engine Manufacturers have built today’s diesel engines using state of the art technology. They have fashioned parts to match in near perfect fashion. We can understand, through this article, that breaking-in this modern marvel of technology is more important then the manufacturers have lead us to believe. Furthermore, we can appreciate that following their claims can result in an engine that is wrought with inefficiency, sloppy fitting parts, and oil consumption problems. Following the guidelines and warnings set forth in this article will provide anyone who desires maximum efficiency and power out of his engine many miles of trouble free operation.
Once the rings and cylinder have "mated," they will have worn away a considerable amount of their roughness. They will wear slower than they did when they were new. This reduced wear rate indicates the end of break-in, and a decrease in oil consumption should be obvious to the owner / operator. Furthermore, blow-by and fuel dilution should also be reduced but may not be so obviously evident. Be aware that engines employing Plasma faced ring technology will take a longer time to break-in. These rings tend to wear far slower than chromium-plated rings. The plasma ring’s hardness allows it to wear the cylinder wall in a more aggressive manner while only polishing the ring surface. Eventually the cylinder wall wears to the shape of the ring and subsequent cylinder wear evolves to a polishing process. This extended process drastically improves the sealing potential of the cylinder, which will correspondingly reduce blow-by and the amount of physical wear on these components. Therefore, we can safely say that the plasma faced ring / Ni Resist insert combination greatly extends engine life. Unfortunately, the price of this better seal is a longer break-in period.
So the big question is: How long does it take for an engine to break-in? Outside of the rings being hard as rocks and just taking their own sweet time to mate to the cylinder bores, the greatest factor is how the engine is broken-in. Most engines will be broken-in after running for some time, but some ways of breaking-in an engine are far superior to others as they are more likely to produce low blow-by and near zero oil consumption.
Therefore, I will lay out some recommended DOs well as definite DON’Ts:
1. DON'T run the engine hard for the first 50 to 100 miles. It is recommended that the engine be operated around the torque peak (1500 to 1800 RPM) in high gear. This loads the engine very gently, and allows the internal parts to "get acquainted" without any extreme forces.
2. DON'T let the engine idle for more than five (5) minutes at any one time during the first 100 miles. (Even in traffic. ) Remember those loose fitting rings, and possible fuel-oil dilution that were noted above? (Fuel Dilution is very common when diesels idle, even with well broken-in engines. ) Well, if that fuel is allowed to contact the main and rod bearings during break in (not really good at any time), you might be looking at an engine that will always consume some oil and one that may not produce power or mileage as expected. In the first few miles of break-in, the bearings are mating to the crank, rods, etc. It is imperative during this time that the lubrication qualities of the oil remain robust. Fuel in the oil will reduce its ability to absorb shock and float the rotating parts in their bearings. Contact between bearings and journals will occur more frequently which will result in additional friction wear. This will ultimately reduce the tight tolerances between the bearings and journals. What was originally a tight fit will be sloppy and will never be able to mate properly.
3. DO drive the engine at varying RPMs and speeds until about 1000 miles. The idea is to alternately heat and cool the rings under varying RPMs. Manual transmission-equipped trucks are the best for this as they typically employ engine compression to slow the vehicle during normal operation, this constantly allows for varied RPMs. This can also be done with automatic transmissions, but it requires that you manually downshift the transmission into the lower gears while driving. Typically, most people with automatic transmissions operate their vehicles in Drive or Overdrive gear positions without making these manual shifts. When their vehicle is decelerating and the speed falls below 38 mph the transmission has little influence on engine RPM. This is because the torque converter unlocks and the auto transmission does not downshift to lower gears in the same fashion that manually shifting does. My suggestion to those with auto transmissions is to find an empty parking lot in the evening, and drive back and forth across it in the lower gears. (This can be done with standard transmission trucks as well. ) Each time revving her up close to redline and letting engine compression slow it back down. This gets the rings a bit hot, but the compression braking allows the pistons to cool with high oil spray flow and no fuel load. Keep doing this for a number of runs, or until boredom sets in.
4. DO put a load on the engine at around 1000 miles, and get the thing hot! Diesels are designed to work, and in many cases, they operate best under a load. Baptize your engine with a nice "initiation load," to introduce it to hard work. Keep the revs up (but watch the EGTs), and make sure the coolant temps rise. Hooking up your trailer and finding some hills to pull works great for this. After the 1000 mile pull, just drive it normally, always making sure to let the engine get up to normal operating temps (no 1-mile trips to 7-Eleven). Towing is ok but remember to not overload and to monitor your gauges carefully erring on the side of caution. Under these conditions, I have seen most diesels completely break-in between 10-15,000 miles, and have always been able to tell that point from mileage gains. One may also notice that the "symphony" of the engine also changes slightly at this point.
We know that Engine Manufacturers have built today’s diesel engines using state of the art technology. They have fashioned parts to match in near perfect fashion. We can understand, through this article, that breaking-in this modern marvel of technology is more important then the manufacturers have lead us to believe. Furthermore, we can appreciate that following their claims can result in an engine that is wrought with inefficiency, sloppy fitting parts, and oil consumption problems. Following the guidelines and warnings set forth in this article will provide anyone who desires maximum efficiency and power out of his engine many miles of trouble free operation.
