Engine Hours - What is a lot?

[Latestarter1]

I know this issue quite often pops up on this forum from time to time and there are differing opinions of what represents a lot of engine hours for our boat engines.

For no reason other than being curious I popped on to some trucking forums to see what they are saying about average mileage as we have marinised of truck engines installed in our boats.

It would appear that some of us are perhaps getting a bit too worked up about the number of engine hours we put on our engines. The average truck does 100,000 miles a year with many doing a lot more when they are on double shifts.

So as a rough estimate, if a truck is on a double shift which I assume is 2 x 8 hours, then that's over 4000 hours per annum. Some of these trucks are running for a fair number of years so it seems 30,000 to 40,000 hours isn't impossible over it's working life.

So by comparison, the 1300 hours on my Volvos would suggest they are just about brand new!

Cor I thought I had done this to death a million times!

Marine vs automotive duty cycles bear no comparison whatsoever....

Consider this Volvo D13 460 rating (published B50 life 1.3 million kilometers) with Volvo I shift 12 speed transmission operating at 44 tonnes.

I shift will be doing a little dance keeping engine spinning around 1450 rpm at 56 mph, engine load will be cycling between 200/300 hp sometimes even less except on most extreme climbs.

Volvo Penta D13 700 marine engine, 690 hp @ 2300 rpm WOT running continuous output say 300 rpm off the top with propeller demand of 500 hp using 2.5 exponent.

Apples oranges and a few tangerines!

Live expectancy of heavy duty diesel engine in marine leisure market you will never wear it out so why is there any discussion?

Marine hang on bits (charge air coolers etc) a totally different story. Fuel filtration, a dirt particle the size of a red blood cell has the potential to bring a modern engine to its knees. Some injectors are now approaching 1k apiece.

Firefly has it right.

 

[CX54WEK]

Engines may last. What about the outdrives after 15 years in the drink?

According to some ours should have dropped off, rotted away, or blown itself into a million pieces by now.

It hasn't.

It's like anything else, maintenance is the key.

 

[kashurst]

I spoke to a Volvo person about this and their view as a marine diesel engine in a planning boat should be good for at least 30 years, doing about 100 hours a year. So about 3000+ hours. Obviously this depends on good maintenance, and not using muppet service people who bu@@er things up. In practice then we probably won´t wear an engine out if looked after

 

[oldgit]

Came across pair of 2008 Perkins M130 engines up for sale..6 cylinder .6.... litres.Make that 2000 hours PA.
Removed from commercial boat. ....
Back on sale after bench testing,no smoke or issues can be seen running.
7.500 hours.
Boat re engined with more powerful engines.

 

[ari]

Seem to remember mention in MBM a few years ago about a commercial pilot boat that was running regularly every day (something like a 33ft Lochin or similar) with a pair of TAMD 41 200hp diesels (same as you'd find in a nineties Princess 35 or Fairline equivalent).

It had over 20,000 hours on it, had only received normal servicing (ie no strip down/rebuild) and was still running absolutely fine.

High engine hour leisure boats (ie well into their lifecycle) simply do not exist. They're either low hours or they are very low hours.

 

[Gwylan]

Much of those miles will be under sail with the engine turned off though, so a good proportion of those miles aren't relevant to the running of the engine (unless you're really averaging 40mph!)

With planing boats based on the coast the rule of thumb tends to be multiply by 10. So these 'high hour' boats with 2,000 hours on have typically covered about 20,000 miles.

No such thing as a 'high hour' leisure boat in reality, it's low hours/lack of use that kills them.

Sorry, think you misunderstood me.

The bit of horse back arithmetic was aimed at comparing the life of a marine diesel engine measured in hours with the miles covered by a car engine. Just a way of producing a nominal mileage for a boat based diesel engine.

 

[aquapower]

Was in engine room on a ERRV last year and noticed main engines clocks were showing around 128000 hours, think they were B & W alpha, even the new supply/standby boats we look after which are mainly around 12 month old or newer are clocking up the hours quickly.

 

[oldgit]

According to some ours should have dropped off, rotted away, or blown itself into a million pieces by now.

It hasn't.

....Yet

 

[Firefly625]

Cor I thought I had done this to death a million times!

Marine vs automotive duty cycles bear no comparison whatsoever....

Consider this Volvo D13 460 rating (published B50 life 1.3 million kilometers) with Volvo I shift 12 speed transmission operating at 44 tonnes.

I shift will be doing a little dance keeping engine spinning around 1450 rpm at 56 mph, engine load will be cycling between 200/300 hp sometimes even less except on most extreme climbs.

Volvo Penta D13 700 marine engine, 690 hp @ 2300 rpm WOT running continuous output say 300 rpm off the top with propeller demand of 500 hp using 2.5 exponent.

Apples oranges and a few tangerines!

Live expectancy of heavy duty diesel engine in marine leisure market you will never wear it out so why is there any discussion?

Marine hang on bits (charge air coolers etc) a totally different story. Fuel filtration, a dirt particle the size of a red blood cell has the potential to bring a modern engine to its knees. Some injectors are now approaching 1k apiece.

Firefly has it right.

I feel like I've just come up in the New Years honours list... At least someone was listening.

 

[aquatom]

The best way to wear out your engines is to go down to the boat every other weekend and run the engines on the berth with no load.

 

[oldgit]

The best way to wear out your engines is to go down to the boat every other weekend and run the engines on the berth with no load.

Or maybe just maybe ..use it

 

[CX54WEK]

The best way to wear out your engines is to go down to the boat every other weekend and run the engines on the berth with no load.

We have neighbours who go one better then that.

They visit their boat perhaps once a month, usually on a Sunday.

They get to boat, fire engines up and within 30 seconds they have revved them up in neutral with first the superchargers and then a minute or so later the turbos whining away.

After maybe five minutes of this abuse, they turn the engines off, lock the boat and head home.

The boat has not been off it's berth for at least five years.

 

[Deleted User YDKXO]

Not even that.
It's purely dealer BS, aimed at selling something for the higher possible price while taking the partial exchange at the lower.

Actually M the dealer is right. Generally speaking on the used boat market, high engine hours means lower value. By high I mean more than 70-100hrs per year. And there is a good reason for that which has nothing to do with the engines. A boat with higher engine hours has been used more and that means more wear on all the other components like generator, pumps, aircon, fridges, toilets etc and more wear on the woodwork and soft furnishings. There are obviously exceptions to this where a keen owner who has used his boat a lot has also been particular about keeping his boat in good condition. However I have looked at a lot of used boats in my time and by and large, the higher the engine hours, the saggier the boat will look

In any case, its not strictly true to compare engine hours in boats with trucks and other machines. Boat engines are usually right at the top end of the power range that the manufacturer offers for that engine and it is an undeniable fact that, generally speaking, the more power you extract from an engine, the faster it will wear

 

[MapisM]

All agreed in principle, but don't forget that the dealer used this argument in the context of a 14 yo boat with 1200 hours.
It's from this viewpoint that his objection doesn't hold water: the boat is bound to have a low(ish) value 'cause it's old(ish), not because its engine hours are higher than normal...