Diesels.

[cuttlefish]

I am finally looking at a couple of boats which are close to my desired specs. I just wonder if anyone could give an opinion on used diesels (turbo-charged)? I am sure they would be costly to replace, but are they prone to probs after a year or three?
And anything else to watch out for?

Thanks,
rupert.

[chewy]

Bit like any engine really, if its looked after it'll have a long life. Quite a few marine diesels are marinised car and truck engines.

[JSP]

Maybe easier to find out what donky's they have in them and then ask.

[jwalker]

There have been problems with Yanmar diesels cracking blocks and Bravo drives failing when coupled to these engines. Do a search here and over on Boatmad and you'll come up with various discussions on the subject. Boats have been sold on because the problem has been severe. Be suspicious of one with a new drive on an older engine. That initially may seem like a good thing but...

IMO, many diesel installations suffer from lack of planning to keep water out of the engine bay, either generally or if there is a watery incident.

The seal between the drive/transom shield and the engine needs to be kept in perfect order because this is all that prevents the sea getting at the engine and entering the boat. It is often a rubber bellows so suffers normal rubber fatigue with age and use.

[tonka]

i have twin yamaha 240hp diesels in mine 1994 original engines and legs , i service both every 150hrs ,and look after them , also drive a boat at work with iveco,s fitted ,done over 12000 hrs well serviced as well and they run as sweet as a nut, so id say alot of it comes down to how they have been looked after previously and some engines are better than others of course,

[cuttlefish]

some good advice. The problem is when you're looking at a second-hand boat, it's not always easy to learn how well they've been looked after.

[LURCHER]

What make of engines are you looking at ?

[cuttlefish]

The ones on the Redbay, Excalibur, and other cabin/canopy ribs you find for sale here and on the web.
Yamaha, Volvo, etc.
I notice, for example, that there is a Volvo 350 Supercharged on the Excalibur site. How reliable is that likely to be?

[jwalker]

This is not the case for all Volvo engines but it is the case for the ones you are likely to find in a rib; the engines use both a supercharger and a turbo charger. The supercharger runs at low speed and the turbo takes over at higher engine speeds. This arrangement prevents the turbo lag and lack of throttle profession which is a feature of some other diesel engines. Reliability of the system is good.

[JSP]

Can recommend Mermaid. Dads got two 6ltr lumps in his boat and they are great engines.

[Andy Gee]

Originally Posted by jwalker

This is not the case for all Volvo engines but it is the case for the ones you are likely to find in a rib; the engines use both a supercharger and a turbo charger. The supercharger runs at low speed and the turbo takes over at higher engine speeds. This arrangement prevents the turbo lag and lack of throttle profession which is a feature of some other diesel engines. Reliability of the system is good.

I would agree with Jeff, the system is good but like any system when one component fails it all goes to pot. When the supercharger fails you cannot get the boat on the plane unless you tow it fast enough to get the revs up to allow the turbo to come in.
Go for the Yamaha which doesnt have that problem.
HTH
Andy

[cuttlefish]

for that.

[jwalker]

Ooops... profession = progression just in case you hadn't sussed it.

[B36]

Originally Posted by rupert

I am finally looking at a couple of boats which are close to my desired specs. I just wonder if anyone could give an opinion on used diesels (turbo-charged)? I am sure they would be costly to replace, but are they prone to probs after a year or three?
And anything else to watch out for?

Thanks,
rupert.

Yanmar 6LP/BravoX makes a good combination. Bravo1X 1.50:1 Revo4 prop.

All the problems you hear about are related to owners who treat their boats like cars, soon as they have finished thrashing it to within an inch of its life shut it down and walk away! They also shout loudest when things go wrong.
Crack block issue was on early LP's Only happens through abuse. all LP's are fitted with factory brace.

[The Beard]

Originally Posted by chewy

Bit like any engine really, if its looked after it'll have a long life. Quite a few marine diesels are marinised car and truck engines.

Almost all marine diesels up to a certain size are marinised versions of truck engines, although some installations are truck engines that are adapted (marinised?) and start a new life in boats.

Most diesels used in leisure boats are very highly rated, powerwise, in comparison with the truck engines they are based on. For instance, the Volvo D12 can be rated up to 715 hp in comparison with the 440 in a 44 tonne truck.

The Cummins B-Series 5.9 can be had with something in the order of 425 hp as opposed to about 250 in an 18 tonne wagon.

The IVECO website lists all its marine diesels in a number of different specs, depending on the kind of use.

http://www.ivecomotors.com/en-uk/Pro...ages/home.aspx

[The Beard]

Originally Posted by JSP

Can recommend Mermaid. Dads got two 6ltr lumps in his boat and they are great engines.

I'm pretty certain they are based on the Ford 6 cylinder that used to be found in the Ford D-Series from the late '60s into the late '70s and the first generation Cargos.

Good, reliable motors, with simple 2 valve heads and rotary injectors.

The only thing I can think of that would stand against these engines in a RIB is the power to weight ratio. The 3 litre IVECO or 2.5 Volvo
might be more useful for leisure use.

http://www.ivecomotors.com/en-uk/Pro...es/S30230.aspx