mercruiser 1.7 diesel 120 hp

peter 24/7 · 21 October 2003, 19:08

Looking to put one into a 7m.
Enough power ? What alternatives should I consider.
Any comments would be appreciated.

Aging Youth · 21 October 2003, 19:25

Hi Peter,

Welcome to Ribnet.

IMHO the mercrusier engine is a surperb piece of kit, Idealy suited to a Rib 6.0 to 7.0m.

From experiences in friends boats crusing speed is 25knots comfortable and will run all day & night. Top speed is 30-32 knots with a 21" prop.

Running costs are 1 litre per nautical mile. Enconomy and Durability all in one engine.

However, depending on your requirements there are bigger diesel engines & drive units out there. Furthermore, with the development of the PASSAT Turbo diesel engine and the new Volvo Diesel only time will tell how good these engines are, I do not think they have been proven yet on reliability or durability.

I hope that is of some use.

Regards

Andre · 21 October 2003, 20:56

Hi Peter

welcome to the forum

I hv a Parker 630 with the Mercruiser 1.7 TDI linked to the Alpha One drive. It is a superb engine and having done 180 hours since August 02 I know what I am saying. Like Kevin said max speed on a 6.3 mtr rib is 32 knots and comfortable crusing speed is 24/26 knots

You say you want to fit the engine in a 7 mtr rib . What make?

the total weight of my rib with full fuel (100 ltrs) is 1050kg

Mike C has a Humber 630 with the same engine and I am sure he will add his own comments

Andre

peter 24/7 · 21 October 2003, 21:36

Looking to buy a Ribcraft 7 m, will 120 hp be enough,or should I go upto a Yanmar 240 ??

thewavehumper · 21 October 2003, 21:48

How heavy is the Ribcarft Hull?

Richard B · 21 October 2003, 22:18

Hmm, just had a look at Ribcraft's package pricing...

Save yourself £476 and go for either the Yamaha200hpdi or the Optimax225. The £476 can go towards the first year's fuel bill, then after the marine duty exemption expires in a couple of years, you'll be in the same situation at 1 litre per mile, but you'll still have a big grin on your face on a Monday morning after every weekend on the RIB.

Go on, you know it makes sense!

DGR · 22 October 2003, 09:31

Peter24/7,

It looks like your going through the same decision making process as me - but you are a bit closer to actually spending the cash!!

I've looked at the various threads on petrol vs diesel (originally I wanted a 7 - 8 m RIB with twin O/B petrols), but it all seems to come down to diesel engines being expensive to start with, but you recover the cost in cheaper fuel and resale value (if you use it enough).

If fuel duty really is to be applied to diesel for marine usage - all the benefits disappear in a puff of (black) smoke. Having said that, I can't find anything definitive on when (or if) it is likely to happen.

I still want a diesel 7-8m RIB - but Richard B's post is making me a tad uncomfortable.........

Louise · 22 October 2003, 09:38

Diesel better for safety every time, but for boats under 8m the economic argument, whilst currently strong, will disappear whilst the UK remains in the EU, albeit in a half-hearted manner.

DGR · 22 October 2003, 10:27

Louise,

Is the changing duty on marine diesel a European thing then?

If the EU can mandate the duty laws, why can't they give us cheaper fuel in the UK?!? Just a thought...

John Kennett · 22 October 2003, 10:42

Quote:

Originally posted by peter 24/7
Looking to buy a Ribcraft 7 m, will 120 hp be enough,or should I go upto a Yanmar 240 ??

I wouldn't put the 120 into a 7m boat. It's just about OK in a 6.5 metre RIB, but they're not quick.

As well as producing a disappointing performance, under powering your boat will also affect the resale value when the time comes. I reckon you'd be better off all round with the 240.

John

Louise · 22 October 2003, 10:56

Quote:

Originally posted by DGR
Louise,

Is the changing duty on marine diesel a European thing then?

If the EU can mandate the duty laws, why can't they give us cheaper fuel in the UK?!? Just a thought...

Hi,

I'm afraid I have no idea! Other half (Richard B) has an annoying habit of posting while logged in as me! Hopefully he'll see this and answer your question.

Sorry I can't help.

Louise · 22 October 2003, 10:57

Sorry! Seem to have posted twice!!

Quote:

Originally posted by DGR
Louise,

Is the changing duty on marine diesel a European thing then?

If the EU can mandate the duty laws, why can't they give us cheaper fuel in the UK?!? Just a thought...

Hi,

I'm afraid I have no idea! Other half (Richard B) has an annoying habit of posting while logged in as me!

Hopefully he'll see this and answer your question.

Sorry I can't help.

jwalker · 22 October 2003, 11:03

Quote:

Originally posted by peter 24/7
Looking to buy a Ribcraft 7 m, will 120 hp be enough,or should I go upto a Yanmar 240 ??

There're only 112hp at the prop, 120 at the flywheel. It's not much.

Richard B · 22 October 2003, 11:04

Sorry DGR - that was me logged in in the wrong context (again!)

Yes - The UK government applied to the EU for an extension to the reduced tax on non-DERV (Diesel Engined Road Vehicle) diesel fuel, but this was granted with an epiry date (2006?) and it's going to be difficult to justify another extension for this with the imminent harmonisation of taxation which the EU is quite keen on.

UK petrol prices aren't much different from our nearest EU neighbour, but French DERV was down to about 50p per litre in September. They have a 2-tier marine diesel pricing, but I think that the cheaper marine diesel is only available to commercial (or just fishing?) vessels.

DGR · 22 October 2003, 11:27

So, does the harmonisation mean that UK fuel tax/duty would be reduced across the board to align with the continent?

I'm considering getting an 8.5m RIB, with a big diesel inboard (240-300hp?). Big diesels appear to be (almost) ludicrously expensive to spec on a new boat, but I can't find any realistic comparisons to see whether it is worth spending the money.

As someone mentioned on a previous diesel vs petrol thread, the views expressed tend to support whatever it is people have got themselves - but I guess that's just human nature!!

Either way - I'm still on the diesel side of the fence (for now)...

Dylan...

Aging Youth · 22 October 2003, 12:21

."So, does the harmonisation mean that UK fuel tax/Duty would be reduced across the board to align with the Continent?"

IMHO This government will not reduce the cost of fuel only inline with europe. As I see it they will only increase the taxation on Marine Diesel.

Whoever, is Chancellor is not concerned about who it will affect, there only interest is to gain another form of revenue through taxation.

Just because the E.U. have harmonised prices we probably will not.

Any legislation that comes through Brussels dictates the rules but not many countries apply those rules except Britain. However, only when it suits them. Hypocracy at it's best!

Sorry if this sounds a little soap box but I feel that we already pay enough for our sport, why should we expect to pay more.

Boating should not be not just for the wealthy, it is a sport that I love, but at what price?

Regards

Andre · 22 October 2003, 12:44

I agree with JK.
6.5 is the max length of rib for the Mercruiser 1.7L TDI

Andre

DGR · 22 October 2003, 15:08

Aging Youth,

Yep, that would be about right. I was reading an article on diesel (oh, how these cold winter nights just FLY by), about a bloke that was runing his Land Rover on used vegetable oil from his local chippie!! The chip shop sold it to him rather than paying someone to cart it away for disposal, the Landy owner bought it for 4 or 5p a litre - everyone a winner - except the tax man!! He got done for not paying road fuel duty. He got caught 'cos his car smelt funny......

Mike C · 22 October 2003, 16:27

Hello!

For 7 Mtr, I would consider something bigger than the 1.7. The thing about the 1.7 is that it is light. But newer ones come out all the time!

As for diesel increasing to road prices. Well, that's what they say but even if it does, you will (or should) still go further than you would with petrol because it is a more efficient fuel. (That's why diesel cars go so far on a gallon!)

But.... On the Continent, as far as I am aware, they have two diesel pumps. One white, one red. You have to be a commercial operator to buy the red. I haven't seen much movement in this country for marinas to put in extra pumps yet. So, what's the betting they will just put a tax onto red diesel in 2006, (or whenever it is - can't remember). That would be far simpler..... and if that happens hopefully it will start off small and may be many years before its gets to road prices.

In other words, who knows what will happen in 2006 (ish)? I can't imagine them just stuffing the full duty on red.... The fisherman will go mad..... and there seems to be no movement for a two tear one.... So maybe we should wait and see and in the meantime fill up a boat for £45!

Oh, and if you catch fire.... what would you sooner be sitting on? 150 Litres of petrol or diesel???!!!

Mike C