Princess 50 engine options

[Rickard]

My friend is interested in a 2002 Princess 50 who has the TAMD74 480hp engines. Boat is ashore and the broker can´t tell any numbers about speed etc
Does anyone have experience of how it performs with these "small" engines? How underpowered and tired is it?
Option(which most boats of this size and year has) was the D12 675hp who has tons of more torque. Must be a huge different
I guess this particular boat will be hard to sell due to the 480hp engines? Stupid to buy?
My friend mostly cruises at 7 knots so he still considers this boat if it can be bought for the right price

 

[oldgit]

Bump this up !
Suprised no comments.
If the buyer is only interested in low speed cruising would have though 900HP would have been more than sufficient.
Hours and paper proof of engine servicing important, would be nice if boat was being used very recently rather than been lying unused for years and years.
Would also hope that on a boat of this class interior is immaculate as well.
A little research on this forum regards problems with engine management systems on some older boats fitted with these engines might well be worthwhile.

 

[dunedin]

Perhaps soon the larger engined boats will be difficult to sell and more modest ones may be in higher demand?

On an inland waterway one horse power would easily tow a boat that size.
You could do the maths but doubt need more than 50hp to do 7 knots (except against a gale).
Big engines pootling at low revs are a bad idea. So in principle for that buyer smaller is better.

 

[oldgit]

....and the era that finally Princess noticed that on a such a prestigeous boat, a manky ladder to the fly no longer cut the mustard, even if it did have wood steps. P48/50.
Why were we so late to the game ?

 

[Sticky Fingers]

That’s a big boat for those engines, though they were the standard when new IIRC. Later boats have D9s or D12s which are in a different league.

It will definitely be capable of cruising at 7 kts though. Top speed maybe mid 20s? (guesswork).

 

[Sticky Fingers]

Bit more on this. MBY review of the P50 from 2005 remarked on the earlier version having TAMD74 options... suggested that they got 29 knots under test, which is surprising, but pretty good really. Maybe they're a viable option after all.

 

[Rickard]

Boat has 1500 hours and no telling how it´s been run
My guess is also top speed mid 20s
If they reached 29 when tested it new I´m a bit surprised. Empty boat of course but probably with anitfouling
The D12 is a lot heavier and uses more fuel even at low speed so that´s good...

 

[Sticky Fingers]

Boat has 1500 hours and no telling how it´s been run
My guess is also top speed mid 20s
If they reached 29 when tested it new I´m a bit surprised. Empty boat of course but probably with anitfouling
The D12 is a lot heavier and uses more fuel even at low speed so that´s good...

Yup. The key thing will be to sea trial it, hull and props / stern gear cleaned and normally loaded eg half fuel and water. It probably won’t make 29 kts, but if it makes and can hold 26-27 kts (say) at WOT continuously without overheating then it’s probably Ok. Anything low 20s or overheating problems I’d be walking away.

Another point to bear in mind m those engines tend to deposit soot on the transom. If that’s going to be an issue then probably best to look for a D9 or D12 powered example.

 

[dunedin]

Boat has 1500 hours and no telling how it´s been run
My guess is also top speed mid 20s
If they reached 29 when tested it new I´m a bit surprised. Empty boat of course but probably with anitfouling
The D12 is a lot heavier and uses more fuel even at low speed so that´s good...

Is there any great need to do more than 20 knots in a 50 foot boat? Most don’t do long voyages, and why is it an issue if takes an extra few minutes? They have the same accommodation and view when they get there.

 

[PowerYachtBlog]

The Princess 50 (mk.1) was available with D12 675hp in just some months after its launch in late 2020.
With 675 it reaches like 34 knots. I had a 50 from 2002 for sale (now sold) with those engines some years ago.

 

[Rickard]

Is there any great need to do more than 20 knots in a 50 foot boat? Most don’t do long voyages, and why is it an issue if takes an extra few minutes? They have the same accommodation and view when they get there.

20 knots and the boat sits pretty bad in the water. 23-24 is a lot better speed
Also the big difference is that the TAMD74 will need overahul way before the D12 as the TAMD74 have to work so much harder at cruising speed

 

[Sticky Fingers]

20 knots and the boat sits pretty bad in the water. 23-24 is a lot better speed
Also the big difference is that the TAMD74 will need overahul way before the D12 as the TAMD74 have to work so much harder at cruising speed

I don’t think that there’s any doubt that the D12 engine boat will be better, it’s a significant improvement over the previous generation engine. It may be a lot more money to buy of course. Overhaul costs of the 74 may be lower. Fuel burn at a given speed, the D12 may have a slight advantage but there would not be much in it.

 

[Momac]

I thought it was good for diesels being worked hard. There are plenty of concerns expressed about diesels being run under light load . Seems to me you can't win on this forum .
Diesels in motorboats rarely wear out in normal use with rebuilds being more likely due to some failure or other eg an major overheat due to a cooling system issue and not due to wear and tear.
Surely the gearing/props on the lower HP engines are different to the much higher HP engines such that the lower HP engines isn't going to wear out quicker .
Obviously the lower hp boat is not going to be so fast as the higher hp boat but that isn't an issue for many people.
If you want to get somewhere fast then a boat is probably not the best mode of transport.

 

[volvopaul]

Just seen this , I remember one some years back in Portsmouth .
My opinion on this is if you want a performance boat the engines are too small , you really need the D12 715 or equivalent Caterpillar , this boat was available with both . If you’re not bothered about planing all the time then it’s ok , but remember when you want to sell it , it will have a very limited audience.
Nothing wrong with the 74P in the right boat , my view is 46ft is the limit for this engine .