inboard engine: pro and con

Daniel Vanesse · 29 January 2004, 11:15

Hello,

I would like to buy a new rib ( about 6.3m ) for long range costal cruising. I want it simple, versatile, efficient. What about fitting it with an diesel inboard engine, e.g. a Mercruiser 120hp? Can anybody advise ?

Best regards

Brian · 29 January 2004, 11:41

Daniel
Welcome to this forum.
Ribnet is REALLY going international now!

I would not like to recommend a particular brand of rib for you because there are so many factors to take into account (your price range, will you be towing the boat or will it be left on a mooring, how many people on-board etc) but..........
I can certainly recommend you get a diesel inboard.
The advantages to you are :
simplicity
reliability
and the availability of fuel

The Mercruiser 1.7 is said to be an ideal engine for a 6m type rib. This assumes you are not a high-speed racer or professional water-ski instructor!!
There are several people on this forum with boat/engine combinations similar to the one you are considering, and can certainly give you some good advice.

simmons0 · 29 January 2004, 12:21

Ive looked into it very hard and i seem to be in a sililar situatiuon to you.

The mercruiser is a great engine and will cost you peanuts to run, the only problem i can think of with it are, price and the space it takes up.

In the next few days i will either order an rib-x with 115 suzi 4/s or a 6m solent with the mersruiser diesel. Everyoen on this site seems to think they are very slow whereas humber reckon with the right prop on a 6.3m it will to 40 knots and Lee Fairweather says that their 6.5m with that engine does 42knots!

Andre and mike c are both runnign 21 inch pitch props, It will swing a 25inch on a 6m rib.

Daniel Vanesse · 29 January 2004, 13:37

Brian,

you are right, I should also have mentionned that:
- I am no high-speed racer: reliability rather than top speed is
my main concern
- yes, I will quite often be towing the boat:
max width 2.55m is required to comply with our regulations
- people:
- max 6 adults ( no diver so far ) for a one day cruise
- 2 ( and a lot of stuffs ! ) during long holiday cruise
( camping, possibly sleeping aboard )
- price: assuming that a 120hp diesel should rather be compared
to a 150hp 4/s than a 115 2/s, price is in the same range, so ...

simmons0 · 29 January 2004, 14:03

Over in England the price is definatley not similar.

A solent 6m with 115 suzuki 4 stroke costs 18k
A solent 6m with the mercruiser costs 22.5k

Engine is a lot more expensive, engine cowling is expensive, the hull modifications are expensive and the fitting is far more expensive than an outboard.

Saying that you save a lot of money on fuel, and the boat will be worth 4k more than a similar petrol when you come to sell it.

Brian · 29 January 2004, 16:14

This is quite interesting.
Remember, it is ONLY the UK that has cheap (red) diesel. Other European countries do not have this "concession" and pay roughly the same for a litre of petrol or diesel..
Diesel engines are more expensive here in the UK.
Is there a link between these two things?
We try to calculate the extra cost of the engine versus the lower cost of the fuel.

For the sake of comparison, what is the cost of a diesel engine versus an equivalent petrol engine in continental Europe?

Daniel Vanesse · 29 January 2004, 17:16

First, one should not compare apples and oranges: a diesel engine has much more torque at low revs than a petrol engine with same power (for a boat, the torque is more important that the peak power), so a 120hp diesel must be compared with a 130 to 150hp 4/s.

Average price in France and Belgium ( VAT included ) as of December 2003:

Mercruiser DTI 120hp: 15600 €
Honda 130Hp 4/s : 15210 €
Honda 150Hp 4/s : 17800 €
Susuki or Johnson 115Hp 4/s: 14000 €
Susuki or Johnson 140Hp 4/s: 15500 €
Yamaha 115hp 4/s: 15500 €
Yamaha 150hp 4/s: 17800 €

In luxembourg, about 5% less ( VAT is lower ).

Price of diesel and petrol varies a lot from country to country, e.g.
- Germany: same
- Belgium, France: diesel is 10% less
- Luxembourg: diesel is 15% less

About "red" diesel, it is available in some countries, but I must still inquire a bit more about that. More to come ...

Keith Hart · 29 January 2004, 17:28

Interesting about the engine prices (diesel v petrol), seem to prove Brian's point.

Diesel inboard - reliability, longevity, cheaper fuel (in the UK)

Petrol outboard - more room in the boat, you can berth where the harbour dries out

Ohhh, tough call.

Still if you buy a secondhand boat someone else will have paid for some of the extra cost of the diesel.

Keith Hart

simmons0 · 29 January 2004, 17:33

Actually the drying out isnt problem because the alpha 1 leg lifts up above the bottom of the hull and with prices like those go for the diesel anyday.

gavin · 29 January 2004, 19:45

Even cheaper here in West Britian than on the Mainland, I mean in ( Ireland) we pay euro .25 cent approx per litre, we mix it with milk and drink it its called Jack

Aging Youth · 30 January 2004, 07:53

Hi Daniel,

I think that based on the infomation that you have provided, the choice would be a diesel boat.

I have had the pleasure of driving 2 different hulls both with Mercury Diesel 1.7. The economy is brilliant and the for long distance cruising fast enough!

I know that costs do differ but for long term ownership and residual re-sale value diesel will be worth more.

If you look under the Boats for Sale there is one good 6.5m diesel for sale, no vat to pay and only 1 year old. So all the depreciation has been paid for, must be worth a look.

Happy hunting & Good luck