Volvo Penta 12 liters block

MapisM

MapisM

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Having learnt some interesting things about Perkins Sabre engines with my previous thread, I would now appreciate any expert view on another engine I'm interested in: the TAMD122.
In this case, I already heard some (generally rather positive) experiences from people who had it on planing boats, in its 600 HP/2050 rpm version. And I know that it was a very popular choice till 6 or 7 years ago.
But the version I'm more interested in is the continuous duty one (380 HP/1800 rpm, which I never found on pleasure boats).
Common sense would suggest that it should be even more reliable than its stretched brother, but common sense doesn't always rule....
Thanks in advance!
 
If I hear the term 'stretched' again on this site I will blow a gasket!

Can we get down to some terms which actually mean something in engineering terms.


Reliability and durability are separate. Manufacturers measure reliability in terms of RPH (Repairs per hundred) during an engines warranty term. Durability is an engineering life prediction based on dyno and field test data. Measure of durability is referred to as B50 (the most common) or B100. If an engine has a B50 life of say 10,000 hours that means that the manufacturer PREDICTS based on their data that 50% of the engines built to that specification will reach 10,000 Hrs without failure. Warranty and policy data is constantly baked into the equation to ensure that the warranty accrual i.e. the amount of money built into the plant cost of an engine is a realistic amount.
If this figure is incorrect it will reflect in the engines profit margin.

Now you can see why I have a a personal head gasket problem when the statement about one rating of the same base motor being more reliable than the other. If the 600 Hp has an RPH of say 20 for say water pump failure so will the 380!

Now look at durability. I would suggest the TD122 has a B50 of say 20,000 hours. If you go to the data sheet and calculate the fuel burned to get to 20,000 Hrs then use the same total fuel figure burn against the hourly rate for the 600 version OF THE SAME BASE ENGINE this will help you establish the potential engine life of the higher rating of the same engine.
.
before unless you have Detroit two strokes a leisure will never get old enough to explore the durability of an engine before it is brought to its knees by failure of a marinisation component.

The engine you refer to has a very sound history, however smokes for a pastime. The issue is once again the health of marine components is critical if you are considering purchace. Why more people do not get their local franchised dealer to carry out an engine survey in the U.K I will never understand.

When Volvo replaced the TD 122 with the D12 the block was very heavily revised, still had the empty cam gallery from the 122, but became a lot heavier. The key was that the D12 block would go down the same machining line as the 122 saving a massive investment. Also all D12's are not the same around 2000 there was further revision to the block making it heavier again.

Now D12 has been replaced by D13 the block is a very distant relative of the 122. Redundant cam gallery has gone and the timing gears are on the back of the engine.
 
Very interesting reading, im wondering who you are and what connections you have? you are a newish user im wondering if you have been watching this site for a while.
 
Woah! Lateboater! That was like a controlled explosion of knowledge!

Informative and entertaining. Heard burn/power/life expectations explained many times before, but not with such enthusiasm!

Mapis, your enquiry sounds like a very long lasting engine based on the greatly reduced fuel burn.
 
[ QUOTE ]
If I hear the term 'stretched' again on this site I will blow a gasket!
Can we get down to some terms which actually mean something in engineering terms.

[/ QUOTE ]
First of all, thanks for a very interesting and clearly well nformed reply.
Btw, I fully agree that marinization components (together with poor maintenance) are the killers of leisure boat engines, more than wear and tear of the engine itself.

Having said that, I have no difficulties to apologize for the improper terminology, but let me explain what I meant - though I suspect that you actually understood that perfectly.

The two engines I compared have the same block, but - among others - with the following differences:

First version:
380 hp/1,800 rpm
Rating 1 (continuous unrestricted - tugs, ferries, and the likes)
Fuel consumption: 212 g/kWh (=59 kg/h at max rated power)

Second ("stretched" /forums/images/graemlins/tongue.gif) version:
600 hp/2,250 rpm (btw, the 2,050 in my initial post was a typo)
Rating 4-5 (leisure high performance boats)
Fuel consumption: 239 g/kWh (=105 kg/h at max rated power)

Now, aside from the conclusions that common sense would already suggest just based on these figures, if we match them with your definition of durability, we get an expected life of the second engine which is 56% of the first one (11,236 vs. 20,000 hours).

See, I accept that "stretched" does not mean anything in engineering terms, but I hope you'll also accept that it is a rather effective way to summarize all the above in one single word, innit? /forums/images/graemlins/smile.gif
 
Thanks Lateboater

Do you know when the D13 will be available as a marine engine? The D11 is available, but currently Volvo still list the D12 series as their next size up. Thanks
 
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