Fuel consumption Volvo D12-800 engines Fairline Targa 52

[Ndorp]

Dear forum, i am a proud Fairline Targa 43 owner with 2 Volvo TAMD75 engines and considering to buy a Fairline Targa 52 with 2 Volvo D12-800 engines. I am preparing a comparison in fixed and flexible cost before i can decide whether the difference in costs it is worth it for me. I live in an area where it takes me 1 hours from the sea but also thousands of opportunities inland. In ither words 80percent of my trips will be around 9-10 nm ph and 6 nm ph. Is there any-one who can help me what i may expect in fuel consumption running at these speeds and what the speed and consumptions is when running idle in Drive mode. The Fairline’s weight is approx 17MT. Would really appreciate your help.

 

[PowerYachtBlog]

I know from certain numbers I have been given, that the Fairline Targa 52 is one of the less thirsty in this category of 16/17 meters hard top boats, build from around 04/5 to 10.
She is also the smaller in length and also the slimmest.
Out of mind I remember very competitive consumption numbers of around 6 liters per nm at around 25 knots.
Most of the competition is around the 7 liter per NM range at more or less the same speeds.
But most of the competition (SS Portofino 53 {57ftloa 22t}, Pershing 50 21 t and wider, Princess V53 wider and a bit longer, Altantis 54 about 6.5 lpm) is also bigger and heavier.

 

[[2068]]

The curve below is for one D12-800 engine.
I don't know which RPM would correspond to 9-10 nmph or 6 nmph.

300 Litres an hour at full speed

 

[volvopaul]

The curve below is for one D12-800 engine.
I don't know which RPM would correspond to 9-10 nmph or 6 nmph.

300 Litres an hour at full speed

View attachment 93474

And that’s each engine

 

[PowerYachtBlog]

The numbers I was given was at 140 liters per hour at 23/24 knots and 1700 rpm. Which comes to 6 liter per nm, very good for that size of boat.
I think a Sunseeker Portofino 46 drinks more or less the same fuel.

 

[Pinnacle]

Guys - the OP Wants to know the fuel consumption of the boat at between 6 and 9 knots. What Hurricane would call pooling speed.
My guess would be that at 6 knots (could well be tickover) the consumption would be around 10 litres per hour per engine.

Thoughts??

 

[Portofino]

7 L / hr first click @7/8 knots with 40% load showing on 12.8 L I 6 s none CR .
Anywhere between 17/20 tns .
Nudge up to 9/10;knots near 800 rpm that rises to 18 L per side ..so 36 all in .

fly in the ointment is the EGTs never go above 190 degrees and FWIW coolant temp above 60 .
Thats ok for short hops etc but not too sure I would be happy running a planning boat at sub 200 EGTs for excessive periods .

Might be worth increasing the oil change Fq ? For the sake of the “ soot “
Or buying a boat more suitably powered for the river .

Engine soot is a common byproduct in diesel engines. Soot is formed as the result of incomplete fuel combustion. Diesel fuels are composed of hydrocarbons, containing both carbon and hydrogen, and when undergoing complete combustion, the only byproducts are CO2 and water. Fact is, no diesel engine is completely efficient and complete combustion does not occur. Complete combustion would require a very lean ratio of fuel to air, whereas real engine conditions exhibit richer fuel mixtures. The less air that is present in the ratio, the more favorable the conditions for soot accumulation.

Soot formation is more pronounced in newer, but any diesel engine. While fuel is injected during the compression stroke and ignited spontaneously from the pressure in diesel engines. Diesel engines produce fuel-dense pockets in the combustion chamber that produce soot when ignited. Newer exhaust gas recirculation (EGR) diesel engines, designed to reduce NOx emissions by routing part of the engine exhaust stream through an intercooler and back to the intake manifold, further compound soot problems in diesel engine oils.

Excessive soot concentrations in oil can be caused by a number of factors. Worn out rings or injectors, excessive idling, poor fuel spray patterns and incorrect air-fuel ratios are major causes of soot formation. A faulty fuel nozzle may spray more fuel than desired, increasing the fuel-to-air ratio and causing incomplete combustion and soot accumulation, or the air filter may become clogged, decreasing air supply and increasing the fuel-air ratio.

Soot particles are spherical in shape and 98 percent carbon by weight. They are a very small size of around 0.03 microns, but they often agglomerate to form larger particles. Although the majority of soot produced during combustion exits through the exhaust, some passes through the rings of the combustion chamber and enters the engine oil. As long as these soot particles remain suspended in the oil and are not allowed to agglomerate, they pose little risk to engine parts. It is up to the motor oil dispersants to keep soot particles dispersed. However, in high soot conditions, dispersants can become quickly depleted.

High soot load conditions lead to loss of oil dispersancy as oil dispersant additives are consumed. As dispersancy is lost, soot particles agglomerate and form larger particles that build up on engine surfaces. This soot and sludge eventually impedes oil flow, and it can also form in oil filters, blocking oil flow and allowing dirty oil to circulate through the engine. In addition, high soot levels within a motor oil increase its viscosity, further impeding oil flow and increasing engine wear. Anti-wear additive performance is also affected in high soot conditions as additives are gradually removed from the oil by adsorption to soot particles, leading to increased wear and premature engine failure.

Another negative effect of high soot conditions is the formation of carbon particles on the piston ring grooves, causing degradation of the oil seal between the ring and cylinder liner and abrading the ring and liner. As the gap between the ring and liner increases, combustion byproducts such as gases and unburned fuels blow into the crankcase, a problem known as blow-by, eventually causing expanding gases to lose ability to push the piston down and generate the power necessary to propel the vehicle. Horsepower is lost and fuel efficiency decreases. Ring sticking and poor heat transfer from the piston to the cylinder wall can also result. Carbon, varnish, soot, wear metals, acids and HEAT are all normal operating factors to consider when planning an effective diesel maintenance program.

Current industry standards outline acceptable levels of oil contaminants through a standardized oil sample test programs. These tests are available through engine manufacturers and testing laboratories. These standards have been set by the Society of Automotive Engineers (SAE), the Automotive Petroleum Institute (API) and the engine manufacturers worldwide.