akeeva
08-25-2011, 10:23 PM
Akeeva is a 1968 50' MY with about 4,000 hours on her 8V71Ns. We bought her in 1999 and had our mechanic remote the oil filters in 2000.
On July 10 this summer we lost our port engine when a cylinder liner broke. Other problems with the engine became apparent; we are almost finished with a complete rebuild (ouch!). We also had the Allison pulled and checked out while the engine was out of the boat.
The injectors tested out fine. After some investigation, our (new) mechanic feels like he has figured out the cause of the liner breakage - the hose to/from the remote engine oil filter was too small (a size 12). Apparently there is a DD spec book that specifies the minimum hose size to use with remote oil filters on the 2-cycle DDs. In the case of an 8V71, the minimum size is a 20, considerably larger than the 12 in place. The book also says that the hose run to the remote filter should not exceed 9 feet.
Our mechanic's theory is that the hose didn't allow for the circulation of a sufficient volume of oil to adequately cool the engine. Excessive heat build-up caused the piston to seize and break the liner.
Just an FYI for all of you that have a 2-cycle DD with a remote engine oil filter.
Park
aboard Akeeva, in Seattle
On July 10 this summer we lost our port engine when a cylinder liner broke. Other problems with the engine became apparent; we are almost finished with a complete rebuild (ouch!). We also had the Allison pulled and checked out while the engine was out of the boat.
The injectors tested out fine. After some investigation, our (new) mechanic feels like he has figured out the cause of the liner breakage - the hose to/from the remote engine oil filter was too small (a size 12). Apparently there is a DD spec book that specifies the minimum hose size to use with remote oil filters on the 2-cycle DDs. In the case of an 8V71, the minimum size is a 20, considerably larger than the 12 in place. The book also says that the hose run to the remote filter should not exceed 9 feet.
Our mechanic's theory is that the hose didn't allow for the circulation of a sufficient volume of oil to adequately cool the engine. Excessive heat build-up caused the piston to seize and break the liner.
Just an FYI for all of you that have a 2-cycle DD with a remote engine oil filter.
Park
aboard Akeeva, in Seattle