Engine hours

[MapisM]

Always been happier to have older and more basic engines and this would tend to support that view in terms of longevity.

I sympathize with your view in principle, but I don't think the rationale behind it is just because older engines were more "basic".
The problem with newer/fully electronic engines is that the builders used the opportunities offered by electronic control mostly for squeezing more power (=higher prices) out of the same old block, rather than maximizing efficiency at the same power levels.
As a result, no prize for guessing whether the very same block is overall more durable in its "X hp/Y rpm" configuration or in its "1.5*X hp/1.2*Y rpm" configuration.....

 

[Bouba]

Also with modern fully electronic engines you loose that "I could fix this" sense in an emergency, which can be very comforting.

 

[Phildorset]

good thread - and quite timely, has anyone had any first hand experience of damaged or badly worn, rusty bores etc on any low hours engines? ten year old big Cats with less than 200hrs on for example? I've read about the dangers - but have any of us suffered directly and don't mind sharing the story?

 

[Portofino]

As a result, no prize for guessing whether the very same block is overall more durable in its "X hp/Y rpm" configuration or in its "1.5*X hp/1.2*Y rpm" configuration.....

There are so many variables in "marine engine durabiltiy ,it's an oversimplification to just linear increase in Hp and rpm
= decrease in durability .

Killer is "marine ageing " as explained above -salt water and it reacts with the bolt on bits like the coolers .

They don,t actually blow up like Lewis Hamiltons F1 engine (s) after 3 races

Also all the electo twackery in modern engines could actually lead to a longer life .eg Load factor % displayed in MAN,s
It's only natural back in the factory for the R+D bods to tinker with 2valve vs 4vslves , bigger turbos , variable vane turbo,s
Common rail , bigger after coolers to dense up the air , re shaped exhaust manifold , -lighter piston, crank , rods , vslve gear ------ etc etc etc .
Then bench test to destruction x 100 -or what ever ? --then to market .
Drivers are "arms race " with competitor s on one hand and the ever moving emission playing field

It's sitting unused in salt water that knackers em , the quality of the bolt on,s -and the EGT -
Exhaust Gas Temp - excess - mainly in boats " on the edge "caused by overloading ,too many Kg,s fouling , owner giving too much throttle -trying to set a certain historical / brochure - speed -it's a cumulative effect .

 

[Rivers & creeks]

I am looking at a 1400 hour boat at the moment with a 2600 hour generator and i am suitable put off!

J

Neither of those hours mean that the engine is any more than run in if it's been well serviced. You could end up adding a zero to those figures if they're looked after.

 

[MapisM]

There are so many variables in "marine engine durabiltiy, it's an oversimplification to just linear increase in Hp and rpm = decrease in durability

Well, of course it's a simplification, but let's take a practical example:
In the very early 90s, the MAN V12 engines installed on boats like BartW Canados, which was the most powerful engine in their range, had a mechanical governor and was rated for 1100hp.
I don't know by heart for how many years that remained the top dog in MAN range, but at least till the late 90s (I have seen the very same engines on a 1998 SL62, for instance).
By the mid noughties, MAN V12 had electronically controlled common rail, and in boats like Deleted User Ferretti it was rated for 1200+ hp (and there was also a 1300hp version, IIRC).
Nowadays, they are squeezing 1900 hp out of that block.

Now, I fully agree that there are many other variables to consider, but AOTBE, do you really think it's wise to expect the same durability from two basically identical blocks, when one of them has an output of 1100hp and the other of 1900...?!?

 

[Deleted User YDKXO]

Now, I fully agree that there are many other variables to consider, but AOTBE, do you really think it's wise to expect the same durability from two basically identical blocks, when one of them has an output of 1100hp and the other of 1900...?!?

No is the short answer to that. It is not only in the boating industry that engine manufacturers compete to offer engines with the highest power density and smallest footprint. I see the same thing in construction machines. You're lucky if you get 10yrs/10000hrs out of an engine these days whereas 20yrs/20000hrs used to be the norm 25yrs ago. Mind you its not entirely the engine manufacturers' fault. Ever tighter emissions and all the extra junk on engines that entails means that engines run leaner and hotter which is never a good combination for longevity

Its no coincidence that in bluewater boats for which engine longevity is vital, the builders are fitting lower revving, lower power density engines than are commonly fitted in a planing boat

 

[Portofino]

Well, of course it's a simplification, ------------/---------do you really think it's wise to expect the same durability from two basically identical blocks, when one of them has an output of 1100hp and the other of 1900...?!?

In a leisure boat - Yes , it's actually happening

In a rail car -No

 

[rubberduck]

And here is the answer !!!!!!!

http://www.boatsafe.com/nauticalknowhow/enginelife.htm

 

[[164147]]

I got it from a Volvo Penta product manager and 2 of my authorized VP service centers. Ask yourselves how many drives reach 2000h without major work?

How many engines would you expect to last to 2000 hours without major work? Typically that's anywhere from 10 - 20 minor / major services costing anywhere from £2k - £5k alone. A turbo won't last 2000 hours and you'd be looking at around £2k to replace one on a Volvo depending on the model. Then there's the alternator, exhaust elbow, heat exchanger etc etc.

 

[A_8]

How many engines would you expect to last to 2000 hours without major work? Typically that's anywhere from 10 - 20 minor / major services costing anywhere from £2k - £5k alone. A turbo won't last 2000 hours and you'd be looking at around £2k to replace one on a Volvo depending on the model. Then there's the alternator, exhaust elbow, heat exchanger etc etc.

I don't think that's the same, the problem with out drives is specific in that the surface treatment on the gears will wear off between 1-2000h (obviously depending on how the drives are used or how much torque per hour they have had to deal with if you will), when the gears are worn there is no point changing them as it will cost more then getting new out drives. You still have your odd £2-3K work that very likely needs to be done before the gears fail.
Lack of service and water ingress will potentially kill the gears even quicker.

 

[[164147]]

Why isn't it the same? Mechanical items all have a a serviceable lifespan. You could argue the same point for a gearbox in a car - 2000 hours is around 80k miles. Would you complain if you had to replace it or is that a reasonable lifespan?

You can buy a reconditioned DPH outdrive for £2k so I really don't see a problem.

 

[[2068]]

My D4 Manual has 1200 hours as the time where it's recommended you strip down / overhaul the DPH outdrive.
If water has got inside, then you're going to hit trouble sooner, but there's no particular reason why a DPH drive shouldn't do 2000hrs+.

 

[Rivers & creeks]

Why isn't it the same? Mechanical items all have a a serviceable lifespan. You could argue the same point for a gearbox in a car - 2000 hours is around 80k miles. Would you complain if you had to replace it or is that a reasonable lifespan?

You can buy a reconditioned DPH outdrive for £2k so I really don't see a problem.

I'd be furious if a car engine, boat engine or gearbox died at 2000 hours. That's a pitiful lifespan, only appalling maintenance and gross misuse could cause that. Outdrives is different but "normal" stuff going at 2k???

 

[Stats007]

You've clearly never owned an Italian car!

 

[Rivers & creeks]

Or a French one.

 

[[164147]]

My old Lotus Esprit V8 used to eat the French gearbox every 20k miles.

 

[A_8]

I was only trying to be helpful and you are welcome to believe what you want but I am not making this up and I've seen it myself. If you are happy getting new drives when you need no problem.

Good luck with a recon unit, why do you think they would only be £2K.

 

[[164147]]

I suggest you speak to Coastal Rides or SAL Marine - a good portion of their business is reconditioning outdrives.

 

[petem]

I suggest you speak to Coastal Rides or SAL Marine - a good portion of their business is reconditioning outdrives.

Hmmmm. Coastal Rides get mixed reviews. Their surplus stock sell off stuff seems to be OK, but people have been critical of the rebuilt components, so proceed with caution.