Brand new high end diesel engine - Volkswagen Marine

[LuckyLady]

Force 8

In 2009, a brand new high end diesel engine for luxury speed boats will enter the stage: The Volkswagen Marine TDI 350-8

Volkswagen Marine TDI 350-8

Technical data TDI 350-8
Engine type Eight cylinder turbo diesel
Fuel system common rail direct injection
Charge turbocharger with variable turbine geometry
Boost intercooling seawater tube heat exchanger
Cylinders V 8
Displacement [cm3] 4.134
Stroke [mm] 95,5
Bore [mm] 83,0
Compression ratio 16.4: 1
Performance (ISO 3046) [kW] 257
Performance [hp] 350
at 4,200 rpm
Specific power output [kW/l] 62.3
Appr. piston speed [m/s] 13.37
Max. torque [Nm] 700 at 1.900 rpm
Min. specific fuel consumption [g/kWh] 210
Weight* [kg] (approx.) 450
Alternator 120 A
Electrical system 12 V


Audi's 4.2 litre V-8 diesel is an engine without precedent and without immediate competition. Being offered only aboard exclusive, power oriented vehicles like Audi Q7 and A8, this engine serves those who wish to be pushed back into their seats whenever they only touch the accelerator.

While its sheer torque is equivalent to sizeable truck engines, the engine offers exceptionally civilized manners. Piezo-controlled common rail injection, the typical refinement of a modern V-8 engine and uncompromising engineering allow this power plant to be nearly inaudible, unless its huge power potential is challenged.

Major players in the quality boating world have demanded this engine ever since first stories were heard about it, and now that the marine version is ready, its potential truly offers new options for boat design:

Its wide engine speed range allows easy application and propeller choice, enabling low maneuvering speed without trolling valve and exceptional acceleration.

Its immense power allows replacement of big block gasoline V-8's without sacrifices in top speed, whereas acceleration onto the plane will be stunning to anyone who is used to gasoline power.

Fuel savings against gasoline options will approach 50% in typical uses, extending range correspondingly.

A dry weight of the fully marinizied unit around 450 kilograms along with extremely short engine build invites more fuel capacity, additional accommodation or storage.

[Fritz]

V-8 and 4200 RPM- The motor will probably beat itself to death.

[seapower]

I want to post soooooooo bad, but my finger's just won't work right. Frank, Seapower

[thomas70]

Volkswagon has had several TDI engines in the marine market for several years. A couple years ago when we were build bay style boats with single diesel power they really tried pushing them on us.

[seapower]

I'd like to say I was excited by this product, but I can't. I've seen some of the VW product in lower HP in sail boat application's. As long as they are running they'll get you down the creek, but when they break, look out. That's when the real hard crying start's. Part's for repair's that I've dealt with are hard to get and very, very expensive. Sorry not my cup of tea.. Frank,SeaPower

[dunn6253]

Seapower, quick question. What type of fuel injectors are usually in the current marine diesels? On the new Ford trucks, we just went to piezo type fuel injectors. It was hammered in our heads at school for the new motors how finicky(sp.?) this type of fuel injector is. Maybe different operating standards for the new VW motors, or do you think there are going to be a lot of fuel injection problems with these motors. Just speculating here, trying to learn a little about marine diesels, thanks for the help seapower.

[seapower]

Dunn, the current engines for the most part are the type you are talking about, with the common rail systems. The fuel will have to be much cleaner than before because of the much closer tolorances and extremely high fuel pressures. As you probably already know the common rail acts like a hydraulic accumulator with the injector's being opened by electric impulse (voltage). The older systems would allow contaminant's of about 40 micron (the human eye can see roughly 40 micron and larger) to actually pass through the system, (trash of that size would ussually accumulate somewhere if there was alot of it, but would pass through the system just the same). Compare that number to the micron rating's on these newer engines, most cases 10 micron primary , 2 to 3 micron secondary, with absolutley NO WATER!!!! Kind of put's it in perspective for me. I don't know anything about the engine that LuckyLady posted about, but I am would be willing to bet it has a simular injection system on it. The mention of the variable pitch turbo-charger would lead heavily toward's that aswell. Coming from Europe and the current emmision constraints, I would venture to guess that all would have some type of common rail and electronic timing systems for cleaner burning. The emmision standard's are what is pushing all of the "high tech" system's on the current engines. It's something I'm afraid we are going to have to live with,I'm not crazy about it. I much prefer the mechanical injection system's for marine use, just because of the "simplicity" factor. My feeling is the more gaget's you add on to an engine, the more likelyhood of break down's (and walking to shore isn't ussualy an option). Everything is computer driven now and are supposed to be "water proof". In the marine enviroment we have condensation that becomes a problem with heating and cooling cycle's, problem is our condensation has SALT in it. Salt is Mother Nature's solvent, not aware of any computer's that can tolorate it very well. Frank,SeaPower

[Dunk]

4200rpms is both good and bad.. Mostly bad, but it will make it an easy drop in replacement for a gas engine in the respect it will take basically the same size prop.

High RPM diesel is what you get when you marinize and engine designed for auto use. I wouldn't expect it to live any longer than a 350 Chevy block with the rpm it turns. All thats left is fuel consumption and we won't know that until they get it in a few boats. 50% less fuel sounds kind of wild to me, but who knows it might be it's only saving grace.

Next will be the price??

[seapower]

When you think about making the switch from gas to diesel it's not just about physical size of the engine. Diesel's have more torque (may not be the case with this VW engine). With that being said your prop size will change to take advantage of the extra power, bigger prop equal's bigger shaft in most cases,etc.... It's a much bigger project than most will think, if done properly (for the long haul in time). The problem with the really high RPM diesel's is that the high HP they advertise is not there until the very last few 100 RPM's. I personally would not run an engine in the corner myself. Be carefull, alway's look at your torque and HP curves when buying an engine. HP that you pay for isn't any good if it's in the RPM range that your not going to use. Typically an in-line 6 cylinder is going to have more torque than a vee block, just because of the length of the stroke.Frank,SeaPower

[dunn6253]

Thanks for the input Frank. I don't really deal with marine diesel fuel, so I don't know how refined it is, but like you said it better be with these new common rail systems. It was hard at the begining when trucks went to this type of setup with fuels and such, I hope it also doesn't happen in the marine end of things. A lot more expensive I would think in a boat. Once again, thanks seapower for the help.