41. 25' 38"N 71. 29' 51"E
Barton P Cerra
Yacht and Small
At 41 North Marine Surveying not only do we specialize in all types of marine surveys, we also offer additional services to further investigate your vessels systems. With over 15 years of commercial maritime technical experience and the fact that I am certified ABYC Master Technician I am more than able to carry out the following services.
An inspection and evaluation of a vessel’s engine(s) as well as computer diagnostics is so that you as a prospective buyer or current boat owner can come to understand the true condition of the engine(s) and what repairs and or maintenance may be required to get the engines up to turn key condition. This inspection is very important in determining a more accurate value of the vessel based on the engine(s) overall condition and performance. Some problems may not be visually apparent during a marine survey until the engine survey is performed. A good thorough marine engine survey can save a significant amount of money if problems are found before the purchase or a complete failure of the engine occurs. Computer diagnostics can look deeply into the history of an engine and tell much of how it was treated, maintained and give you a very good indication of its overall condition. I can perform engine surveys and have the technology required to run diagnostics on most marine gasoline outboard and inboard engines and work closely with two very reputable diesel technicians combined are factory certified on all makes of marine diesel engines and generators.
Cylinder testing is a good start when it comes to learning about the overall condition of an engine but it is not a substitute for a full engine survey or a sea trial. Like I previously stated it’s a good start and can give an indication that a vessel is worthy of pursuing or it should be avoided. There are two types of compression tests for engines. The regular engine compression test uses a single gauge and measures the maximum instantaneous compression built by that cylinder. A compression test uses the engine turning to generate the compression in the cylinder for the compression stroke, in which both intake and exhaust valves are closed. A leak down test uses a set of gauges and pressurizes the cylinder with air and measures how much of that air is escaping. I prefer the leak down test which in my opinion is much more accurate in determining the condition of an engine's cylinders. Leak down is the percentage of compression that is lost by the engine, and every engine has some. Like a compression test, a leak down test is accomplished by replacing a spark plug with the tester hose. Unlike a compression test, a leak down tester has two gauges and requires a compressed air source. One of the gauges on the tester shows the pressure at which the cylinder is being pressurized. The other shows the percentage of the pressure that is being lost through leakage. That percentage tells you the condition of the cylinder. As with a compression test, leak down variance should be minimal.
Ocean-going engines although similar to land based engines the environment in which they operate is very different. Marine engines are often situated in holds with little air for cooling, they tend to work harder and hotter and so does the oil. These are all factors to consider when analyzing the oil. Does sitting over the winter cause corrosion? Has the oil been changed appropriately? Is water getting into the oil supply? Oil analysis can help to understand an engine’s condition, it’s like a blood test for an engine and like a blood test it can measure many things most importantly the overall condition of an engine. Oil analysis is always a good idea periodically when you own a vessel to insure that your vessels engine(s) are in good condition, but when it comes to purchasing a vessel it can be very important especially if the vessel has little or no maintenance/service records, but even when a vessel does have its service history well documented it is still a good idea to have the oil analyzed. Considering even the smallest marine engines could cost thousands to repair or replace, pre-purchase oil analysis can save you those thousands not to mention the piece of mind it can give you that your new investment is a good one.
Hull Potential Testing
Stray current corrosion is simply corrosion caused by stray (leaking) current from a vessel out into the water surrounding the vessel. Stray Current leaking from your vessel can have disastrous and very costly effects. The hull potential test is an extremely useful test that can help to determine if a vessel is in fact leaking current. If you have noticed excessive or abnormal galvanic corrosion or you want to see if your bonding system is working up to its potential a hull potential test can shed light on both.