Piston engine problem Brisbane - HOLE
Piston crowns are extremely durable and if a hole in a piston is caused by the entry of a foreign object it will need to be rather large. The ingestion of small objects like small screws, washers or carburettor parts generally remain embedded into the piston crown. However large objects like valves will easily hole the piston crown and even the block cylinder wall. (see photo's Above) Most piston crowns that present with a hole burnt through are on high performance or race petrol engines. Lean air fuel ratio is the common cause. Methanol race engines run An air fuel ratio of around 5.5 to 1(That is 5.5parts of air to 1 part of methanol) while Petrol road cars run 14.7 to 1 AFR. If a methanol race engine runs lean under race conditions within as little time as 10 seconds it can result in a large hole being burnt through the piston crown. Extremely abnormal combustion temperatures are required to cause this damage so correct Air Fuel Ratio on any engine is so very important. Disclaimer Agreement : Every care has been taken in writing this information and procedures, but no responsibility can be excepted for errors, omissions or misuse of this information and procedures. The information available on this site is for your instruction only and cannot be copied for sale, © copyright 2001 UMR Engines
Hole in piston crown
due to valve failure
Piston damage due to
timing chain failure
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Piston engine problem Brisbane - HOLE
Piston crowns are extremely durable and if a hole in a piston is caused by the entry of a foreign object it will need to be rather large. The ingestion of small objects like small screws, washers or carburettor parts generally remain embedded into the piston crown. However large objects like valves will easily hole the piston crown and even the block cylinder wall. (see photo's Above) Most piston crowns that present with a hole burnt through are on high performance or race petrol engines. Lean air fuel ratio is the common cause. Methanol race engines run An air fuel ratio of around 5.5 to 1(That is 5.5parts of air to 1 part of methanol) while Petrol road cars run 14.7 to 1 AFR. If a methanol race engine runs lean under race conditions within as little time as 10 seconds it can result in a large hole being burnt through the piston crown. Extremely abnormal combustion temperatures are required to cause this damage so correct Air Fuel Ratio on any engine is so very important. Disclaimer Agreement : Every care has been taken in writing this information and procedures, but no responsibility can be excepted for errors, omissions or misuse of this information and procedures. The information available on this site is for your instruction only and cannot be copied for sale, © copyright 2001 UMR Engines
Hole in piston crown
due to valve failure
Piston damage due to
timing chain failure
7 Moss Street, Slacks Creek, Qld 4127
