Volvo 5.0 vs 5.7 difference

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ontheplane

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Hi all,

Been looking at a Cranchi with a 5.0gi engine - which I know would not exactly be cheap to run, but I think in a relatively light boat it shouldn't be too bad.

The negotiations aren't going to plan however, and we may pull out.

I have seen another very similar boat, weighs about 200kg more but has the 5.7Gi engine in it - both run duoprops, both Volvo, both similar quite deep V hulls.

The question is, would this slightly larger, slightly heavier boat with a bigger (but still injected) engine use significantly more fuel, or would the difference be minimal??

Also would the jump from a 21 footer to a 25 footer be particularly noticable from a comfort and / or trailering point of view...

Thanks
 
Hard to tell without knowing what the 25 footer is.
The Cranchi 21' is a good boat, and whilst it's bound to be less comfy than an equally good 25', it might be better than some 25' lemons...
 
As MapisM says, it depends on the boat. I trailed a Fourwinns 268 with a Volvo 5.7Gsi for about 4 years. Pocket size cruiser with room and facilities to stay on board.

Fuel consumption varied depending on use from about 6lph at river speeds to 20lph cruising. Averaged about 2.5mpg over 400hrs.

Its a big boat to tow, fine if you plan ahead and go for a decent length of time. But its too big to take out for a day trip.
 
New development

Hi there - the other boat is a Cranchi as well....... Turchese 24

Thing is, I've just found out it's engine isn't an EFi motor at all, but a Carb....

I think that might seal it's fate for me, I suspect that will be burning 40+ lit / hr at cruise and up to 90 lit/hr WOT?

I had a Rinker 260V back in the nineties with a 5.7LX engine - that would do 20Gal/hr at WOT and still used 14gal at cruise - that's about £100/hr roughly!

I'm thinking the bigger boat may just not be viable...
 
Lack of EFI would seal it for me as well, but the 24 is a very nice boat. It's not that much bigger to tow, but it feels a lot bigger on the water. Don't get too hung up with running costs, will £100 a day really make a difference instead of £80 ?

FWIW, buy the boat you want, you will only end up changing it if you don't.
 
No - £100 vs £80 per day wouldn't make a jot.... but the difference between 20lit/hr (£40 - £50 per hr) and 20 GAL per hr (£140 / hr) would.

My other concern would be, if I think like this, as fuel prices continue to rise, will others think like it too and run for the hills.

Does anyone know what the consumption of this 5.8FL engine is likely to be at say 1/2 throttle, 2/3 and full wide open??

Anyone got experience of this kind of engine with a duoprop and in a 2000kg boat?
 
Also I guess, is it possible to retro-fit fuel injection to this engine or would that be silly money?

Also (waits to be flamed) is there anywhere still selling LPG on the pontoon on the South Coast or have they all closed down? I know Cobbs's LPG has gone, anywhere else sell it or is it just road stations now (won't be a big deal as we intend to trail it).
 
That isn't so bad - I could live with that.

Just been quoted £700 to fit a simple vapour LPG system - to that I'd need to add additional bilge blower (for where the tanks are) a second (or even 3rd) tank and a few other safety bits and bobs (Hydrocarbon alarms etc) - Could be quite viable considering the conversions used to cost £3000!!!

So this would take it from say 10gph (£70 per hr) to run down to about 12 GPH on gas so about £40 per hr. Even if we said a saving of £20 per hour - I'd only need to do 50hrs if the conversion cost £1000 in total to break even - then it's ahead of the game.
 
neale said:
I had a 5.7 carb engine in a 2000kgs boat. It wasn't duo prop but it used to burn between 8 and 10 gph (36-45 lph) at around 25 knots.
Click to expand...

Was that in the Bayliner Neale? If so, that's a bit taller so although similar weight, I'd be expecting to get slightly better consumption in a low slung sportsboat...

When I had the 5.7 it was in a 26' cruiser so that weighed aroun 2700kg, but was also tall and wide and threw a Bravo II prop not a duoprop.

Still going to need to get my daughter to go out with an oil sheik tho aren't I!
 
It was in the Bayliner. From memory I used to run it at about 3500rpm. So I guess if you run yours at a similar RPM your consumption per hour would be similar. Your speed might be different so your overall MPG could be better or worse but I think it won't be far out.

As for LPG. The reason the Bayliner now has a nice diesel engine is because the LPG conversion was such a disaster. 30 hours after conversion the engine died. A replacement engine just never ran right. The boat felt spectacularly sluggish after the conversion and when I ripped it all out I weighed the kit. Again this is from memory but the kit alone weighed around 200kgs. I had two tanks with a capacity of around 150 litres so when full I was carrying around 300kgs extra weight.

Then there is the supply chain. It was poor back then but I could at least venture along the whole South coast on LPG. Now there are maybe one or two in the Solent, and if Walter Scott is still on the case, one in Torquay. Other than that I don't know where else you will find it.
 
Trouble is - what did the diesel cost you!

I don't care about the supply - I'll fill up in the morning where I fill my LPG car up.

If it uses say 14 gal/hr and I have 150lit (33 gal) then i'll get 2 and a bit hours of cruising around, that actually might be enough for a day on the water - then fill it up next time.

It's a sportsboat not a cruiser - I got rid of my LPG Rinker for the same reason as you ditched LPG - lack of fill points - but the cruiser was water based, so I had to fill up at the water based fillers couldn't use the land-based ones.

Thing is, you probably spend £10k converting to diesel - that would double the cost of the boat, and I may as well just grimace and buy the fuel!
 
ontheplane said:
Trouble is - what did the diesel cost you!

I don't care about the supply - I'll fill up in the morning where I fill my LPG car up.

If it uses say 14 gal/hr and I have 150lit (33 gal) then i'll get 2 and a bit hours of cruising around, that actually might be enough for a day on the water - then fill it up next time.

It's a sportsboat not a cruiser - I got rid of my LPG Rinker for the same reason as you ditched LPG - lack of fill points - but the cruiser was water based, so I had to fill up at the water based fillers couldn't use the land-based ones.

Thing is, you probably spend £10k converting to diesel - that would double the cost of the boat, and I may as well just grimace and buy the fuel!
Click to expand...

I would definitely not support a financial decision to swap a petrol boat to diesel. It's worth doing for many reasons but financially it doesn't make sense. The way fuel prices are going I think a small petrol engined boat is viable, you just have to accept that it will be expensive to run.

On the subject of filling up an LPG boat at a car filling station. Just make sure that the LPG filling point is somewhere that allows fumes to escape and not accumulate on the boat. When I converted I was told car fillers have a significantly higher rate of gas escape when connecting and disconnecting. Don't know how true this is but marine filling points do use a different nozzle and there must be a reason for this. Just be careful. I'm sure I don't need to tell you how volatile LPG is.
 
Filler will either go on the side, or on the rear transom.

LPG is heavier than air, so when the filler is disconnected, I will make sure the vapour can't go into the boat (it will have a tonneau on).

I would also run blowers as soon as we got to the launch site, and leave them running whilst prepping the boat to launch.

I think they used a different filler just because they wanted to stop people fitting the much cheaper car kits.
 
I personally wouldn't touch LPG for a boat. It's currently just over half the cost of petrol where I am, but I'd be very surprised if you got anything like similar MPG from a V8? I have an LPG system fitted to my Land Rover and whilst it is a very early version and they've since improved, the economy only works when LPG is cheap. Around Devon LPG seems to be stuck around 80ppl and, given an economy of 9-10mpg versus the petrol economy of 17-18mpg, it simply isn't viable. If you can get LPG at less than 50% of the petrol then you will probably save, but given the cost of the conversion, weight of the tanks, space used and additional service costs/risks, I wouldn't bother!
 
I've also just found out that the Vapouriser for a Raw water cooled engine has to be fully marinised as a normal car one will rust in a week after exposure to Salt water.

I think a drop from 19mpg to 9 is excessive - and no it wouldn't then stack up at all.

Volvo will re-power the boat to diesel for me for about £25000 - so that's not really an option either.

I think I need to get definate fuel curve figures for the engine from Volvo and see what they say typical burn will be at a given RPM that should tell me if I can afford to run it - but I think it has to be affordable on petrol or I need to look elsewhere.

Do any of the experts here (Volvopaul, Spannerman, Kawasaki etc) have a link to anywhere on Volvo's website where that fuel burn curve might be available.

The engine is a 5.8FL engine (1992 - 1996).

Thanks
 
ontheplane said:
Hi there - the other boat is a Cranchi as well....... Turchese 24
Click to expand...
Aha. Well, in any sort of sea you will notice the difference. The Turchese is definitely more "solid" than the smaller sister.
The only case where I'd prefer the 21' is if I should use her on a lake, and for waterski.
She has in fact one of the best waterski hulls/wakes, if that's your thing - aside from full flagged inboard skiboats of course, whose wakes are in another league, but not really suitable for cruising.

I wouldn't be too worried by the carburated engine. The Gi is actually nearer to a carb engine that to a modern (multi port) fuel injection engine, and in fact IIRC also the HPs were not much different between the Gi and its equivalent carb version, the Gs.

Of course the 24' will burn a tad more than the 21', but not so much because of the carb vs. injection engine. It's simply a matter of having to move around a bigger boat. In fact, the 24' was also built with the 7.4 liters big block, which is probably more comparable to the 21' with the 5.0 purely in terms of speed.
And anyway, don't be too worried by fuel burn. That's NOT the most critical factor in the cost of ownership of any pleasure boat.

LPG instead, now THAT is something which would make me rather run than walk away from anything afloat!
 
ontheplane said:
The engine is a 5.8FL engine (1992 - 1996).
Click to expand...
Mmm... I didn't see this before posting my previous comment.
IIRC, the FL came with the old style "original" VP outdrive, doesn't it?
And otoh, the Gi on the 21' has the newer "OMC style" outdrive, right?
Which means that probably the first has alu props and the latter s/steel.
If so, that's definitely a point in favour of the 5.0 - more than the injection per se, imho.
 
ontheplane said:
I've also just found out that the Vapouriser for a Raw water cooled engine has to be fully marinised as a normal car one will rust in a week after exposure to Salt water.

I think a drop from 19mpg to 9 is excessive - and no it wouldn't then stack up at all.

Volvo will re-power the boat to diesel for me for about £25000 - so that's not really an option either.

I think I need to get definate fuel curve figures for the engine from Volvo and see what they say typical burn will be at a given RPM that should tell me if I can afford to run it - but I think it has to be affordable on petrol or I need to look elsewhere.

Do any of the experts here (Volvopaul, Spannerman, Kawasaki etc) have a link to anywhere on Volvo's website where that fuel burn curve might be available.

The engine is a 5.8FL engine (1992 - 1996).

Thanks
Click to expand...

It isn't just the vapouriser, consider where you would put the tank(s) and the effects of saltwater air. They are heavy and need to be low down to avoid de-stabilising the vessel - and also well secured. They're unlikely to be aluminium or stainless steel - most likely a fairly hard carbon steel, so corrosion inspection will be necessary and probably difficult. A little escaped gas from filling is one thing, but a compromised tank at 6/7 Bar would most certainly be leathal! High pressure LPG is also cold and there will be condensation unless insulated - which of course brings us back to difficulty of regular inspection... It's also true to say that if you fill tanks to max (around 80%) on a cold day and leave the boat on the water in hot weather, the tanks will quite likely vent. On a car this will escape naturally and disperse in the air, but trapped in the hull of a boat... :eek:

Like MapisM, I think I'd run away... :rolleyes:
 
Ok... lets forget the LPG thing then....

Going back to the two enfgines - I think (from looking) that the 5.8FL does have the newer drive with the stainless duoprop - but I'm waiting for more info on that one.

Other than that - I really don't know what to do - but it might be irrelevant as I've got to see if the owner is likely to accept quite a lot less than they are asking!

But OK - I'm convinced that the LPG thing may not be a goer.

Interestingly Volvo say they "don't give out fuel consumption figures for gasoline engines".....

Too scary are they?
 
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