Blew #1 Piston because of Rev Limiter?
Blew #1 Piston because of Rev Limiter?
I have a good tune on my car. Fully built motor. I have ran my car hard off and on for the past 2 months with no problems. For the first time, i hit my rev limiter and right then and there, i cracked my ringland. What cause this? i thought hondata was ignition cut? Maybe it cut fuel and ran really lean?
Hitting the rev limit puts mechanical stress on the engine via vibration and because there is no combustion pressure. However, a cracked piston land is usually always from excessive cylinder pressure or detonation. If the piston is damaged around the exhuast valve relief then it is probably detonation.
There are many incorrect myths surrounding the rev limiter. All Honda ECUs use a fuel cut rev limiter. When this activates, the fuel is cut. The next firing cycle will have only a very tiny amount of fuel from wall depositis - well below the air/fuel ratio where it will ignite. A fuel only rev limiter is safe. If, however, you use an ignition cut only, you will wash the cylinder wall down during the rev limit, and run the risk of overheating the rings and/or scuffing the bore. An igniton rev limit should only be used with a fuel cut as well.
There are many incorrect myths surrounding the rev limiter. All Honda ECUs use a fuel cut rev limiter. When this activates, the fuel is cut. The next firing cycle will have only a very tiny amount of fuel from wall depositis - well below the air/fuel ratio where it will ignite. A fuel only rev limiter is safe. If, however, you use an ignition cut only, you will wash the cylinder wall down during the rev limit, and run the risk of overheating the rings and/or scuffing the bore. An igniton rev limit should only be used with a fuel cut as well.
Hondata