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All of our curves

We recently had a request from a customer to show all of the power and torque curves of our VGT Series of engines on a single graph, for “at a glance” comparison purposes.

 

 

Take a look at the graph. Note how very flat power and torque curves are on our engines, and compare them to the curves of our competitors. The one below is for a Cummins QSB 6.7, medium intermittent duty (Comparable to VGT 450):

cummins torque 6.7

 

Note the spike in torque on the Cummins. Why does this matter? Well, the Cummins may have a higher maximum torque level, but it occurs at a spike, at a single RPM level. The VGT provides more torque, over a wider RPM range. This translates into lower cruising RPM (thus less fuel consumption) and more power at those speeds.

 

Size Matters: Comparisons Marinediesel Versus the Competition

 

On this site, we have often written about the compact size of the Marinediesel VGT Series, and how our engines will fit into cramped engine compartments when other engines will not. What is the real size difference? See for yourself in the table below!

Manufacturer

Length (mm) Width (mm) Height (mm) Total (m3) % Difference Weight (kg)

Marinediesel

VGT Series

779 825 917 0.589 0%

510

Cummins QSB 6.7

1097 910 857 0.856 + 36.955 %

659

Cummins QSB 5.9

1036 836 831 0.72 + 20.015 %

658

FPT N67

1089 724 786 0.62 + 5.128 %

600

Volvo Penta D6

1037 773 885 0.709 + 18.49 %

699

Yanmar 8LV-370

1133 884 823 0.824 + 33.26 %

435

Yanmar 6LY3 – STP

1071

802

793

0.799

+ 30.259 %

640

Yanmar 6CX-530 1340 886 934 1.11 + 61.33 %

837

 

 

 

Engine Comparisons: VGT500

 

 

This week, we will be highlighting several of our engine models and be comparing them with others that are in the market. Our engines stand on their own merits. All data on other engines is available online. Comparisons are based on closest models / ratings for each manufacturer.

We start with our flagship product: The MarineDiesel VGT 500. Using the Duramax 6.6L as a base, we have created the lightest, smallest, and most powerful marine engine in the market today. Ideally suited for small, very fast craft, the VGT 500 delivers the high performance standards that simply leave other engines lacking.

Figures are based on commercial rating, when possible (Some manufacturers only have one rating, others have multiple ratings.)

Some specifications:

Engine Comparison MarineDiesel Volvo Cummins Yanmar Iveco / FPT
Engine Model VGT500 D6 435 QSB 5.9 6LY3-ETP N67 560
Retail Price (Manufacturer’s Suggested Retail Price, online. Prices may vary significantly. Add’l discounts may be avail) € 41,552 € 57,976 € 44,144 € 41,905 €40,929* (UK Only, Sale Price)
BHP 500 435 472 480 500
kW 373 320 352 353 368
RPM 3600 3500 3400 3300 3000
Cyl 8 6 6 6 6
Displacement (l) 6.6 5.5 5.9 5.8 6.7
Bore / Stroke (mm) 103/98 103/110 102/120 106/110 104/132
Maximum Torque Nm 1130 1040 1278 1280 1500
Time Between Overhaul (hours) 2500 1000 2000 1000 1500
Time Between Maintenance (hours) 100 50 75 50 100
Dry Weight 510 699 612 640 650
Fuel Cons at Top Speed g/kWh 230 208 232 228 215.5
Power / Weight kW/kg 0.73 0.46 0.58 0.55 0.57
Euros per kW € 111.40 € 181.18 € 125.41 € 118.71 € 111.22
Overhaul Cost (60% of New) € 24,931.20 € 34,785.60 € 26,486.40 € 25,143.00 € 24,557.40
Cost at 10,000 hours (Purchase, Overhauls, and Maintenance) € 141,279 € 405,836 € 176,579 € 293,339 € 204,647
Fuel Cost at 10,000 hours, Fuel EUR 0.80 / Litre (Calculated at 435 hp) € 710,476 € 633,905 €733,728 € 696,830 €656,761
Total Cost of Ownership 10,000 hours € 851,755 € 1,039,741 € 910,310 € 990,169 € 861,408

So, engine weights are listed in the table above. What about engine size?

(L) X (W) X (H), in mm

MarineDiesel VGT 500: 779 X 825 X 973 (Note: MarineDiesel engines always allow for remote location of some components, such as the grid cooler, filters, or starter motor. Dimensions, particularly height, can often be reduced considerably or shifted around to a great extent.)

Volvo Penta D6 435: 1,456 X 753 X 897

Cummins QSB 5.9: 1,255 X 836 X 858

Yanmar 6LY3 – ETP: 1,458 X 801 X 793

FPT N67 560: 1,063 X 843 X 766

 

Curves:

When comparing power, and especially torque, curves, you need to keep in mind how the vessel will be used. All engine manufacturers rate their engines differently, many times with several different ratings under a single model. Others, like MarineDiesel, can change the ECU and engine programming to suit a vessel’s mission. The curves below are the most common ratings, but when reviewing, attention must be given that these curves can be different or altered due to rating.

MarineDiesel VGT 500:

Volvo Penta D6 435:

d6 pwr torque

Cummins QSB 5.9 472:

qsb power torque

Yanmar 6LY3-ETP:

yanmar 6ly3etp curves

FPT N67 560:

n67 560 curves

 

 

 

 

 

 

 

 

 

 

Comparing Torque Curves – VGT 400 vs Volvo Penta D6

 

 

MarineDiesel’s VGT Series of high speed marine engines are the lightest and most powerful engines in the marine market today. Don’t just take our word for it, though. Compare for yourself! In this article, we compare the torque curves of the VGT 400 with the Volvo Penta D6:

Volvo Penta D6 Torque Curve

Volvo Penta D6 Torque Curve

VGT400 torque

VGT400 torque

Note the “flatness of the VGT’s torque, as compared to the “spike” on the Volvo Penta.

 

 

 

Diesel versus Petrol: What’s the advantages and disadvantages?

We occasionally get asked by our customers whether or not they should put a diesel engine in their vessel, or a petrol engine. As with everything else in life, there is no single “right or wrong” answer. We manufacture both types of engines, so we are truly non-biased in our opinion. The answer is, “It depends.”

Ask yourself these questions:

What is the purpose of the vessel?

How will the vessel be used?

What are the emissions regulations in my area?

What is my budget?

These all have an impact. So, to make things easier to break down, we will use diesel as a starting point, listing advantages and disadvantages versus petrol.

Advantages

  1. More efficient combustion versus petrol. Diesel engines have a much higher output of torque than petrol engines. Given the same horsepower on two engines (see below), the diesel will provide more work for the fuel spent.
  2. Much longer life cycle that petrol engines. As much as three or four times longer. Petrol engines work “harder” to produce the same power, and are more complex, thus needing more frequent maintenance.
  3. Diesel is cheaper than petrol (At least in most of the world).
  4. Much lower fuel consumption.
  5. Petrol has a greater risk of explosion and fire. Requires greater ventilation.
  6. Diesel engines produce much less heat, and are cooled more efficiently. Petrol engines can require substantial cooling systems at greater cost.

 

Disadvantages

  1. Diesel engines are usually more expensive than petrol engines, often up to twice the price.
  2. Diesel engines produce more smoke with dirty fuel (Though ULSDF required in Europe and the USA is actually cleaner than petrol).
  3. Diesel fuel breaks down rapidly. If engines will sit for long periods of time, the fuel will need to be stabilized or drained.

The pictures below illustrate two MD engines’ power and torque curves, showing a big difference in torque, but producing the same horsepower.

petrol 6-2

MD VGT 400 diesel power and torque curves.

MD VGT 400 diesel power and torque curves.

Life Cycle Cost Calculator

 

 

At MarineDiesel, we often come across potential customer who are confused about which engine to purchase. Yes, there are brand loyalties at play in any power decision, yet, more often than not, cost and price usually plays the biggest part in purchasing decisions, often eclipsing performance or technical requirements.

However, when choosing between two engines, much more goes into the cost calculation than simply purchase price.

Yes, very inexpensive engines are available in the market, usually, but not always, produced in China. Though these engines may be cheaper to purchase outright, their real cost becomes evident when maintenance, service life, and fuel consumption are taken into account.

When choosing an engine, you need to look at the following factors:

Purchase price

Engine rating

Life Cycle

Time between overhauls

Time between service

Fuel consumption

Cost of engine downtime

Cost of spares

Cost of service / labor

All of these factors add to the real cost of an engine, and in comparing one engine to another.

Therefore, in order to make your purchasing decision easier (Whether you choose us, or not), we have made the calculator below available for download for your use, free of charge.

Simply fill in the blanks indicated by yellow, and your real cost is indicated at the bottom. The spreadsheet is pre-loaded with the data from our VGT Series.

We hope you find it useful and helpful in making engine comparisons.

Life Cycle Cost Calculator

 

 

VGT Series vs Cummins QSB 5.9 – How do we Compare?

 

 

The VGT Series of marine engines is MarineDiesel’s flagship product. We originally aimed to make the lightest, most powerful, most reliable engine available in the market, and we succeeded where others have not.

So, how does the VGT Series compare to others?

Price:

MarineDiesel VGT: Mid-range

Cummins QSB 5.9: Low

*Price will vary greatly based on many factors, including import duties and dealer markups, but in general

 

Cost of Spares:

MarineDiesel VGT: Mid-range

Cummins QSB 5.9: Mid-range

*Note: The Cummins engines are sold and serviced through the CMD network, which is largely focused on the recreational market

 

Rating:

MarineDiesel VGT: Commercial / Military Medium to Heavy use

Cummins QSB 5.9: Recreational

 

Engine Block:

MarineDiesel VGT: V-8

Cummins QSB 5.9: Inline 6

*Inline cylinder arrangements tend to produce higher levels of vibration

 

Weight:

MarineDiesel VGT: 500 kg

Cummins QSB 5.9: 658 kg

 

Fuel Consumption:

MarineDiesel VGT: Max 220 g / kWh

Cummins QSB 5.9: Max 235 g/kWh

 

Curves:

Cummins QSB 5.9 Power Curve

Cummins QSB 5.9 Power Curve

MD VGT 450 Power and Torque Curves

MD VGT 450 Power and Torque Curves

 

 

VGT Series vs Yanmar 6LY3 Series – How do we compare?

 

 

The VGT Series of marine engines is MarineDiesel’s flagship product. We originally aimed to make the lightest, most powerful, most reliable engine available in the market, and we succeeded where others have not.

So, how does the VGT Series compare to others?

Price:

MarineDiesel VGT: Mid-range

Yanmar 6LY3: Inexpensive to Mid-range

*Price will vary greatly based on many factors, including import duties and dealer markups, but in general

 

Cost of Spares:

MarineDiesel VGT: Mid-range

Yanmar 6LY3: Expensive

 

 

Rating:

MarineDiesel VGT: Commercial / Military Medium to Heavy use

Yanmar 6LY3: Recreational

 

Engine Block:

MarineDiesel VGT: V-8

Yanmar 6LY3: Inline 6

*Inline cylinder arrangements tend to produce higher levels of vibration

 

Weight:

MarineDiesel VGT: 500 kg

Yanmar 6LY3:640 kg

 

Fuel Consumption:

MarineDiesel VGT: Max 220 g / kWh

Yanmar 6LY3: Max 221 g/kWh

 

Curves:

MD VGT 450 Power and Torque Curves

MD VGT 450 Power and Torque Curves

MD VGT450 Fuel Curve

MD VGT450 Fuel Curve

Yanmar 6LY3 ETP Power, Torque, and Fuel Curves

Yanmar 6LY3 ETP Power, Torque, and Fuel Curves