Sunseeker 34 with petrol engines? Reliable? Fuel?

[The swede]

Hello,

I'm currently looking to buy a Sunseeker 34 Portofino from 1988 here locally. (I live in Southern France).

The boat looks honnest and well priced, but few people have been warning me about the engines. The idea is to replace our 15" bowrider outboard and use the boat for leisure day cruising.

The boat has the classic 7.4 V8's with each 330bhp. They have run for 550h and have been professionally maintained each winter.

I was warned that:

1. These engines are unreliable, wear out quickly and need constant repairing. Correct?

2. I was told that these engines are incredibly thirsty and you really should get diesels.
Now since I do not plan to use the boat daily and for long trips (we use it maybe 1h per week on average), I thought the savings made by a lower purchase price do compensate easily for the extra fuel.
That being said, HOW MUCH does such boat need per hour at cruising speed? Some say 150L, some say 70...

Thanks very much for the advice!

 

[The swede]

For info, the boat is for sale for 18000 Euros.

 

[Nick_H]

A quick Google found this interesting boat http://www.theyachtmarket.com/boats_for_sale/211022/

By the time you've flown to UK to view, then transported it to SoF, it would be twice the cost of the one you're looking at, and it would be a fair bit slower, but it has 2004 diesels with no supercharger, which should be relatively problem free, cheaper to run, and have good re-sale potential.

Mind you, if you're based in Cap Ferrat you don't need an engine, you could row it to a couple of the best anchorages on the planet!

 

[The swede]

Thanks!

I am vaguely aware of the trade off between the diesel and the petrol, i.e. the petrol is with his 2x330bhp probably quite a bit faster than the 2x200bhp diesel and it is more thirsty.

Then again, we use the boat for the occasional afternoon out, and as you said, we never need to get far. So paying 15000 Euros more to have a diesel isn't economically paying off.

Of course, if the petrol needs 150-200L at cruising speed and will need fixing all the time, that does change the problem.

So are the 330bhp petrol engines unreliable? And what does such beast need approx in fuel?



Distracting factor:

I got a Sunseeker 34 XPS with two 200bhp Volvo Penta diesels also offered to me for not much more money. Officially 600h on the clock, 1990 boat, and with a duoprop (whereas the 330bhp petrol has single props).

This now leaves me now with a third question: is 2x200bhp sufficient for a reasonably fast ride in such heavy boat?

 

[Nick_H]

This now leaves me now with a third question: is 2x200bhp sufficient for a reasonably fast ride in such heavy boat?

I don't know, it's certainly borderline, but it's easy to test this by having a sea trial in the boat.

I don't know enough about the specific petrol engines to advise you, but anecdotally petrol engines generally seem to be more problematic than diesel, although parts can be cheaper to buy.

Having said that, outdrives seem to be a lot more problematic than either type of engine, and are usually more expensive to fix as there are no shared parts with road vehicles, so you have Boat Added Tax on everything.

 

[The swede]

Been indeed told that the sterndrives like on such Sunseeker are more prone to having problems than a straight shaft with propellor.

But I assume that's the same issue whether powered by a diesel or petrol.

 

[crazy4557]

I ran a Sunseeker 37 Tomahawk with twin AD41's and whilst it wasn't the fastest boat on the world it was more than adequate. It gave me about 32 knots WOT with duoprops.
I would suggest the 34 XPS would be fine with these motors but that also depends on their condition...only a mechanical survey would confirm that.

 

[stuhaynes]

Hello,

I'm currently looking to buy a Sunseeker 34 Portofino from 1988 here locally. (I live in Southern France).

The boat looks honnest and well priced, but few people have been warning me about the engines. The idea is to replace our 15" bowrider outboard and use the boat for leisure day cruising.

The boat has the classic 7.4 V8's with each 330bhp. They have run for 550h and have been professionally maintained each winter.

I was warned that:

1. These engines are unreliable, wear out quickly and need constant repairing. Correct?

2. I was told that these engines are incredibly thirsty and you really should get diesels.
Now since I do not plan to use the boat daily and for long trips (we use it maybe 1h per week on average), I thought the savings made by a lower purchase price do compensate easily for the extra fuel.
That being said, HOW MUCH does such boat need per hour at cruising speed? Some say 150L, some say 70...

Thanks very much for the advice!

Combined 15 litres on PETROL!!!! Hope you've got deep pockets.... Don't like petrol on boats regardless of which boat it's on. Just my honest opinion.....

 

[Cookee]

I agree with Nick - sea trial them both and you'll know immediately which one is right for you. The critical point is that everyone has their own idea of fast enough and too expensive.

Petrol benefits: The sound of twin V8's is impressive, and with the addition of through transom exhaust you could really upset the neighbours and can be tamed by exhaust diverters so that you have the option of straight through or standard. Reliability is only an issue if they are not properly maintained, regular use is of benefit! Price! Speed!

Diesel Benefits: Diesel torque, cheaper fuel, better economy. Reliability as above.

 

[The swede]

Thanks

I heard these petrol V8's and they are super-silent actually.

I assume getting the exhaust to go through the hull isn't super complicated or expensive, but then you're stuck with the noise all the time, even if you want to cruise silently.

Pardon my ignorance, but isn't there a switcheable option? Or is that just mega expensive?

 

[Cookee]

Thanks

I heard these petrol V8's and they are super-silent actually.

I assume getting the exhaust to go through the hull isn't super complicated or expensive, but then you're stuck with the noise all the time, even if you want to cruise silently.

Pardon my ignorance, but isn't there a switcheable option? Or is that just mega expensive?

Not complicated at all - That's what I was talking about - exhaust diverters, a brand name is silent choice (http://www.knbsupply.com/stdisy.html) so that you can choose how noisy you want to be! All will be from the USA of course!

 

[The swede]

Not complicated at all - That's what I was talking about - exhaust diverters, a brand name is silent choice (http://www.knbsupply.com/stdisy.html) so that you can choose how noisy you want to be! All will be from the USA of course!

Looks grand. Probably will be as expensive as the whole boat

Doesn't it also increase the risk for getting water in, if your exhaust accidentally get submerged?

 

[dustywings]

I have a Riva 38 that had Crusader 7.4L V8 350hp engines when I bought it, these engines are probably the same core engines as yours but marinised by a different company. The boat is 1980 and these were the original engines, they had had a rebuild in 2005 but for the two years I ran them were 100% reliable. The benefits were that they were quiet and there was the V8 grunt the down side was the fuel bills which were horrific and really prevented us using the boat to its potential. I changed the engines last year to diesels and while you will read here on several threads that the cost is prohibitive I found a good value pair of diesels that had only done 600 hours, sold the petrols for a good price and did a lot of the installation work myself. Now we go further in the boat and in a couple of years I will have saved the money it cost me plus we get more se out of the boat and of course there is more value in it when I come to sell.

 

[The swede]

I have a Riva 38 that had Crusader 7.4L V8 350hp engines when I bought it, these engines are probably the same core engines as yours but marinised by a different company. The boat is 1980 and these were the original engines, they had had a rebuild in 2005 but for the two years I ran them were 100% reliable. The benefits were that they were quiet and there was the V8 grunt the down side was the fuel bills which were horrific and really prevented us using the boat to its potential. I changed the engines last year to diesels and while you will read here on several threads that the cost is prohibitive I found a good value pair of diesels that had only done 600 hours, sold the petrols for a good price and did a lot of the installation work myself. Now we go further in the boat and in a couple of years I will have saved the money it cost me plus we get more se out of the boat and of course there is more value in it when I come to sell.

What do you call "horrific" when we are talking cruising speed?

 

[dustywings]

What do you call "horrific" when we are talking cruising speed?

As pm'd 150L per hour when cruising at 23 knots! If faster then considerably more, so i didnt!!!

 

[Mr Googler]

I think a good point has been made there.

The petrol version would be faster but you wont go faster due to the needle dropping!! Probably end up at 25 knots on either petrol or diesel so in some ways top speed is irrelevant.

I would always prefer diesel for various reasons not least of which is the petrol engine probably wouldnt have heat exchanges so seawater, heat and metal are all meeting in those small waterways within the block. Not ideal in the longterm

 

[Balearick]

The boat has the classic 7.4 V8's with each 330bhp.

Personally I'd stay clear of large petrol engines on boats. You'll be at the fuel dock filling up every couple of days. You'll have to be rigorous about venting the engine room for 5-10 mins before and after every use. Plus there's so much more to go wrong with petrol engines. Just my two cents.

(my first boat in the early 90's was a Fairline Sprint with a single Volvo Penta V8 petrol engine, she'd eat through gallons just to warm up on automatic choke before we even left dock!)

 

[Nick_H]

Lets say you've done your sums and worked out that it would take 10 years of extra fuel cost to cancel out the capital saving, so you buy the petrol boat. The situation now is:

- the less you use the boat, the more right you were
- longer trips will blow your sums out of the water.
- It'll cost almost 500 euro in fuel to go to Cannes to watch the fireworks, or 2-300 to go to Antibes or Menton for the night.
- you'll be more worried about breakdowns

Consciously or sub-consciously there'll be a tendency to use the boat less, so you'll maybe save a bit of money in the long term, but have less fun. Your fun factor per euro cost of ownership will be lower, which is the sum that really counts.

When its time to change boats you realise that you'd have got back the extra cost of the diesel boat when you sell, and kick yourself for all those missed days out, and all those trips you passed up on?.....

 

[neale]

I had a single 5.0ltr V8 and it used to burn about 45 litres per hour at 25 knots. So two 7.4's could easily get through 100+ ltrs per hour at a decent cruising speed.

By contrast, a pair of 200hp diesels will probably burn about 60 litrs per hour for a similar speed.