diesel programmers

+1 on CaptJ's comments. Hugely popular with the land-based, skoal-spittin', Grave Digger guys, but who wants to dig a grave at sea?

There are a lot of those guys in Europe in car business. They call it chip tuning. They tune a V6 245 HP Audi Diesel into a 320+ HP hotrod by just changing the software within the electronic engine control system. That makes you losing the manufacturers warranty. You will see them later during their high speed low flying exercises on the German Autobahn. Those engines do not last very long. There is one company in the Netherlands that tunes the Volvo D6-370 engine to above 450 HP. I personally would not thrust this engine anymore.

Just increasing the air pressure and the amount fuel injected cant be healthy for a high performance diesel engine.

Cheers

Hi,

Increasing the HP of your marine engine is pretty simple just like on a car/truck.

Turning that increase in HP into something useful, reliable and long lasting is where the real challenge lies.

Your car when chipped will be used for short periods of full output and extended periods of less than full output. The ability to have your boat at WOT for an hour or three will soon cause a premature end of your lump.

There are also a number of other things to consider. The Props will no doubt need to be adjusted or replaced to match this new found power. Will the shafts and gears handle the increase or will they too need to be upgraded.

You should also ask yourself why you want to up the HP. It will take more than a simple re chip to get most displacement hulls on the plane.

Will the engine be able to get more air from the existing vents.
Will the cooling system be able to dissapate the added heat.

It was engineered to have X horsepower for X amount of all the other stuff.
Best to leave it alone unless your into rebuilding and re-engineering.

Wot?!...

I'll readily admit that I'm new to power boating (though I have extensive sailing, naval and maritime experience) but I was always under the impression that one should reserve the last 10-20% for emergencies.

In fact, back when I was in the navy (fast attack patrol boats), WOT was called 120% (as it truly was 120% of rated output) and, according to the book, we could use that for only 30 minutes once every 6 hours. 110% we could use for 60 minutes once every 3 hours.

I would have though that on power boats the same rules apply. I.e. WOT is a meaningless term unless WOT is truly 100% of the rated output. If it's more then running WOT for hours at an end is going to significantly shorten your engine life. And, considering the minimal speed increase, I would wonder if it's worth it (emergencies obviously excluded).

The flip side is, as far as I understand it (and please correct me if I'm wrong), if WOT equals 100% of the rated output, you can safely use it.

Hi,

The term WOT was used in the context that a boy racer uses his car with the right pedal jammed against the carpet.

The ratings you gave seem very close to what i remember being MTU's spec back in the 80's.

I am pretty familiar with current CAT Ratings.

A Rated Unrestricted Continuous Operation -100% of Rating 100% of the time No cycling or interruption.

B Rated Heavy Duty Operation - up to 80% of the time at rated speed, time at full load 10 hrs out of 12 hrs

C Rated Maximum Continuous Operation - up to 50% of the time at rated speed, time at full load 6 hrs out of 12 hrs.

D Rated Intermittent Duty Operation - up to 16% of the time at rated speed, time at full load 2 hrs out of 12 hrs

E Rated High Performance Operation - up to 8% of the time at rated speed, time at full load 1/2 hr out of 6 hrs

A C 18 which is a common enough engine in the size of boats most are familiar with here starts out with an A Rating of 454 to 587 bhp at 1800 rpm, B Rating of 479 at 1800 rpm up to 671 bhp at 2100 rpm, C Rating of 715 bhp at 2100 rpm, D Rating of 873 bhp at 2200 rpm and an E Rating of 1001 bhp at 2300 rpm. The fuel consumption which is one of the things used to determine service intervals starts out at 21.7 US Gal/hr and ends up at 51.7 US Gal/hr

It is easy to see how cranking up the output results in a larger fuel consumption and accelerated wear of the engine when the periods of operation at the top load condition are exceeded by a lot.

Note: The data quoted above came out of a Marine Engine Selection Guide dated August 2010. The exact powers might have changed a bit but the basics are still the same.

Spot on!

I got that part. We used to call it "steel to steel". As in having the throttle pushed as far as it will go.

Spot on! I was indeed referring to vessels fitted with the MTU 16V-956-TB91 engines. Of course, these were (and still are) popular engines for this application.

So yes, working your engines above the rated output is possible though not recommended. Certainly not long term. What you can actually safely do varies from engine to engine.

To keep safe we monitored the exhaust temperature of each cylinder. Pleasure craft rarely have a common exhaust temperature gauge so that's not an option.

It should be possible to run a diesel long term at (or close to) 100% of its continues rating and, that should not impact engine life. In fact, running at very low power will also shorten the life of the engine. One reason why I troll on one engine (I alternate between the two) rather then both

Diesel power

Having said that, the whole idea that lies behind superchargers & turbochargers is to increase the air (oxygen) and fuel for a given engine and thereby increase its output.

That's the way HP was almost doubled on some engines (e.g. DD 71/92 series which were originally (N - naturally aspirated - version) 300+ HP (8V version) with the later (T - turbo - version) versions almost doubling that to almost 600 HP. And yes, I'm aware of the fact that the N version was actually supercharged but all of that extra air was used to scavenge (flush out exhaust gasses) the cylinder.

And therefore, in answer to thread question, it rather depends on how far the engine in question has already been pushed. And the answer, IMHO, is that modern engines have already been pushed to the limits and any further pushing (e.g. by "chip modding") is NOT advised (though possible) mainly due to accelerated engine wear.

Of course, that opinion holds for us, pleasure boaters with limited wallets. in specific applications (racing, law enforcement, naval etc) where there's more money available, this is less of a consideration.

Modifying the output rating of a current electronically controlled marine diesel through recailbration of the combustion process will compromise the manufacturer's IMO/EPA Emission certifcate and expose the owner to potential liabilities, especially upon resale.

The marine market volume, unlike the on-highway side, is not significant enough to justify a tuner shop to go through the testing process ($$$) and get proper certifcation documents for individual engine lines, and it would kiss your warranty good-bye!

Cylinder head temperature, exhaust gas temperature or even inner turbine temperature (on Turbos) are figures which might be monitored by some electronic engine control systems (a standard procedure for airplane pilots with their piston engines), but really unknown figures to the average boater (because they are not indicated). They just able to watch oil temp and pressure plus coolant temp and off they go.

If some boaters would know what these figures are showing, when using a variable pitch prop and overpitching them for the last knot of speed, or going WOT below rated speed or when using Gori folding props with overdrive funktion on heavy sailboats, IMO, they would be more careful.

On big ships, proficient chiefs watch this figures closely with their instruments or computer programs, as these figures show early indication of engine malfunction, wear and fatigue. Besides correct use, trend monitoring is the best method of ensuring long engine life.

Even on smaller electronic controlled diesel engines like Volvos or Yanmars the electronic flash memory on the EVP can be downloaded, and thats what service mechanics do, in order to find out whether the engine was badly treaded or missused, and there goes your warranty.

I had once an old chief, he could feel, when his engine did not feel well. He really suffered with his baby. Where those man have gone?

Cheers

A lot have been laid off in cost cutting measures, some have fallen over and the rest of us are still here just not as active on the tools as we once were.

You can't "get more" HP out of an engine without paying for it somehow. Most likely (with modern engines) you'll pay through reduced engine life.

Can you keep on plane with 100% load? You should be able to run at that setting pretty safely. Even long term.

In fact, how do you know you're running at 87%? Something you calculated yourself out of the power/speed/fuel graphs?

Your other option is to re-engine next time your engines are due for a major overhaul. And, you would be able to defer a small part of the cost by selling the old cores. There's a market even for worn out engines. HOWEVER, that's a major job and requires $$$. Even if you go for rebuilds rather then new ones.

A note on rebuilds: they're only as good as the rebuilder...

While that's what I do often, in most cases (referring to planing boats) it will NOT be the most efficient speed. In fact, running diesels far below their optimum speed will also shorten their operating life. Even if you do a 30 minute speed run at the end of the day.

Plus, it's fun to go fast

And sometimes its even necessary...