Engine longevity.

[ari]

Thames Police sold a Botnia Targa with Volvo AD41's on outdrives a few years back with 25000hours !
Think it's all down to usage and servicing.

Well the AD41 is one of those 'same block/more power/less life' motors. If 25,000 hours is 'less life' I think I can live with that.

Agree with a lot of the above, regular use and servicing is the key to longevity, not reduced hours. Give me a well maintained carefully used four figure hour turbo diesel over a rarely used rarely serviced three figure hour alternative any day.

Thousands of turbo diesel trucks out there with 300,000 miles or more, they've got to be clocking 10,000 running hours plus.

 

[fisherman]

Yes, I was told average 30 mph. Farmer used to buy a 150hp tractor, run it in then wind the pump open to 180hp. What he hated was the driver screaming into the yard and stopping the engine before it cooled, he said you could hear the oil cooking in the turbo. My engine is nat asp and I never open it up before the temp shows, and always let it idle a few minutes before shutdown.

 

[burgundyben]

Yes, I was told average 30 mph. Farmer used to buy a 150hp tractor, run it in then wind the pump open to 180hp. What he hated was the driver screaming into the yard and stopping the engine before it cooled, he said you could hear the oil cooking in the turbo. My engine is nat asp and I never open it up before the temp shows, and always let it idle a few minutes before shutdown.

Indeed, oil coking happens above 150 degrees C, transient conditions of hot shut down are a prime opportunity.

 

[ari]

Agreed. I always let the engine run at below turbo speed for 10 mins if starting from cold before gradually easing the revs on in stages. Likewise, I never shut down straight away after planing - always 10-15 mins cool down before shutting off.

 

[superheat6k]

Agreed. I always let the engine run at below turbo speed for 10 mins if starting from cold before gradually easing the revs on in stages. Likewise, I never shut down straight away after planing - always 10-15 mins cool down before shutting off.

Nothing like a 2 mile plod out and then back in to the River for a controlled temperature warm up / cool back.

 

[wizzer]

I know a marine engineer that stripped a pair of M225Ti down for a rebuild as they had done 12000 hours in a commercial boat, they we're like new inside.

You'll never wear yours out.

Very interesting to note. I have a pair of M225Ti’s on 1300+ hours in my Channel Island 32 and I was wondering about longevity. I usually cruise at 2000 RPM with the occasional 10 minutes at WOT (2500 RPM).
I’m considering a bigger boat (Aquastar 38), it too has a pair of M225Ti’s, currently on 2500 hours each.

 

[Alicatt]

Yes, I was told average 30 mph. Farmer used to buy a 150hp tractor, run it in then wind the pump open to 180hp. What he hated was the driver screaming into the yard and stopping the engine before it cooled, he said you could hear the oil cooking in the turbo. My engine is nat asp and I never open it up before the temp shows, and always let it idle a few minutes before shutdown.

I had a Toyota Landcruiser Amazon 4.2 Turbo Diesel drove it for 113,000 miles in a year, never had a problem with it apart from the garage making a mistake with the trailer wiring, engine was serviced every week or two and ran sweet. I drove it hard, and carried a lot, then my time with that company came to an end with me moving to another company.
One evening I was heading back up the A1 and my old Landcruiser went past me, I was doing close on 3 figures and the Landcruiser was pulling a cherry picker behind it when it passed. A couple of days later I ran into my old boss and was chatting with him, he was complaining that he had to replace a cracked inlet manifold, Ahh I said, someone running the car hard and then shutting it off and not giving it time to let the turbo cool, I always finished my journeys in the FJ80 with the last 10 minutes of gentle driving to let the temps settle and then let the car idle for a while before shutting it off.
Not got a diseasel boat - yet

 

[A_8]

I don't remember the details now but some thread on this forum years ago explained how engine life was defined ( I think it was how much fuel was being used by the engine) and owning two KAD 43 at the time I calculated an expected 4000h before a major rebuild (provided regular use and service). I don't think all marine diesels are equal in this respect so one story does not apply to all.

 

[oldgit]

Very interesting to note. I have a pair of M225Ti’s on 1300+ hours in my Channel Island 32 and I was wondering about longevity. I usually cruise at 2000 RPM with the occasional 10 minutes at WOT (2500 RPM).

Perkins. 225 HP from 6 litres @ 2500 rpm.
Volvo 235 HP from 3.7litres @ 3700.
Which one will wear out first ?

 

[[2068]]

Perkins. 225 HP from 6 litres @ 2500 rpm.
Volvo 235 HP from 3.7litres @ 3700.
Which one will wear out first ?

The owner of the engine?

Assuming 50hrs / year average usage.

Volvo D4-225 might last 3000 hours if treated well.
I’ll be 113 years old when that Volvo wears out.

Lets assume the Perkins lasts three times as long.
I’ll be 233 years old when the Perkins wears out.

.

 

[Portofino]

Depends how it’s used .
Pootling along at D speed with a planning boat for the majority of the running time might shorten the life .
Use the boat as it was designed or if you can’t change it .


The effect of operating conditions on heavy duty engine valve seat wear
Author links open overlay panelY.S.WangaS.NarasimhanaJ.M.LarsonaJ.E.LarsonaG.C.Barberb
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Abstract
Engine valve seat wear affects engine performance. To improve valve quality and life is a common goal for both valve and engine manufacturers. By performing tests on a valve seat wear simulator, the effect of cycles, load and temperature on heavy duty intake valve/insert seat wear was investigated. The test temperatures ranged from 180 to 650 °C, the number of cycles was varied from 150 000 to 3 420 000, and the test loads were applied from 6615 to 24 255 N. The relationship of valve and insert seat wear as a function of cycles, load and temperature was experimentally established. A load dependent wear transition was found to exist and suggests different wear mechanisms operating in these different regions. Higher temperatures produced lower seat wear, which was attributed to parting agents or oxide films and valve head deformation. The intake valve/insert (Silcrome 1/Silcrome XB) seat wear mechanisms were found to be a complex combination of adhesion, shear strain and abrasion. Shear strain or radial flow was found to be an important valve seat wear mechanism from the microstructure analysis of cross-sectioned valve seats, and two-dimensional and three-dimensional worn seat profiles. The oxide films which formed during testing were found to play a significant role. They can prevent the direct metal to metal contact and reduce the coefficient of friction on the seat surface, thus reducing adhesive wear and deformation controlled wear.

 

[Zing]

Very interesting to note. I have a pair of M225Ti’s on 1300+ hours in my Channel Island 32 and I was wondering about longevity. I usually cruise at 2000 RPM with the occasional 10 minutes at WOT (2500 RPM).
I’m considering a bigger boat (Aquastar 38), it too has a pair of M225Ti’s, currently on 2500 hours each.

Reckon on 10,000 hrs to rebuild, then another 10,000 hrs more. Then you might consider the merits of a new one or repeat again. This was the factory advice.

 

[Portofino]

Perkins. 225 HP from 6 litres @ 2500 rpm.
Volvo 235 HP from 3.7litres @ 3700.
Which one will wear out first ?

Agree no substitute for cubes applies .
All things being equal .

Diesel engines are capable of having a long life when the power to displacement ratio is low. But when they start jacking up the power, beyond what the manufacturer originally intended, that benefit disappears. There is a very simple formula you can apply to estimate service life: simply multiply the cubic inch displacement of the engine times one. The result is the maximum amount of horse power you can have and still expect a reasonable service life. A 6V92 engine is 552 CID; at powers greater than 550, these engines don't last. At 450, they'll go 10 - 15 years easily.
. Now, an 8V71 has a 568 cubic inch displacement; the fact that these engines have a 0.56:1 power/displacement ratio explains why they could run so long.

Conversely, divide the Hp by the CID and the greater the result UNDER the factor of one (1), the longer engine life you can expect.
So here’s a few
Vp D4 225 is 1.04.
Vp D6 370 is 1.01

Perkins 225 is 0.61

Garndner 6 LW @102 Hp from 8.3 L is 0.2 !........so they seem to last a long time

My MAN 2876 is 0.89
MapishM is 0.9 Both in leisure light duty rating s which MAN suggest 1000 hrs per annum ...as Flower Power infers its hard to remotely ever get near this number .Last year was 80 , this year ( Covid ) 40/45 ? ......

The heavy duty are under 1/2 the Hp and many 1000s of hrs per year which in commercial they rack up easily.

 

[Zing]

Another data point. We run our artics for 1m miles before reliability becomes a concern. At 40mph average that is 25,000 hrs. You can do more.

 

[fisherman]

73000 on one of these, posted before

Boats for sale UK, boats for sale, used boat sales, Commercial Vessels For Sale 26.5m Floating Bridge-Chain Ferry - car and passengers - Apollo Duck

 

[Bouba]

Tribology

great word!

 

[ari]

The owner of the engine?

Assuming 50hrs / year average usage.

Volvo D4-225 might last 3000 hours if treated well.
I’ll be 113 years old when that Volvo wears out.

Lets assume the Perkins lasts three times as long.
I’ll be 233 years old when the Perkins wears out.

.

Quite!

And just to add, I'd be most upset if I owned a D4 225 that was giving up the ghost at 4,000 hours through simply wearing out.

These threads crop up from time to time and it's all a bit of a nonsense, leisure boat engines can suffer all sorts of problems (often linked to lack of use or servicing) but very rarely actually just wear out.

Plenty of (I'd say most) 70s and 80s planing boats still happily pottering about with their original engines, and plenty of commercially used fast boats (police, customs, coastguard etc etc) happily running with many multiples of the hours a leisure user is ever going to add.