90hp outboard v's 3.0 inboard

[ianmccabe3]

hi all i have just sold my 16ft 90hp outboard and looking at getting a 18ft bowrider with 3.0 inboard
im just wondering what it would be like on fuel compaired with my old boat and running cost etc
also would it be ok for watersports
i have about £4500 to spend so hope someone can help with some good advise
thanks
ian

 

[vandy]

£4500 is not really enough to buy you a decent reliable bowrider.

You should be looking for at least £7k+

In Inboard engines, corrosion/leak is something you must be very careful of especially around driveshaft and exhaust and if you buy anything dated before 2000 then you should expect that.

Maintanance of inboard engines is also more difficult compared to outboard.

I personally prefer outboard, mainly because I have only owned boats under 23ft!

Have you thought about buying a rib?

 

[moonraker 36]

had a 16ft fletcher with a 235hp o/b.very heavy on the juice..
got a 5.7l i/b heavy'ish but not as bad as the o/b.
4.5k will get you a half decent boat if your willing to look around..

 

[ianmccabe3]

hi all thanks for that info
yes seen a few of each on ebay and may go and look but still wondering about the fuel side of thing is it better the stay with outboard or go inboard
thanks
ian

 

[ianmccabe3]

anymore input welcome

 

[markcw]

Bit of a silly question
Their are so many factors that will change your fuel consumption, hit rought sea and your fuel use will increase, hit flat sea and plain at 30 knots you will use more fuel than just ebbing along, my fuel consumption is allways different its a volvo penta 4.3 gl 3.0 ltr, weather temp will change fuel usage, strong winds will increase fuel consumption if pushing against the wind so so many factors will change the fuel usage.

try not to base your choice of boat via what engine, each engine has different plus and minuses, my inboard is a doddle to work on would never go back to a O/P, big things clummped on the back of the boat, nasty looking to me, rather have the engine hidden.

try to look at it as a package that fits your needs. 3.0 on an 18fter easily tow toys no problem could hit towing at speeds of 40 knots if your happy to be towed at those speeds.

mark

 

[ianmccabe3]

hi mate thanks for that
yes i know all about conditions etc
if you have 2 boats side by side with the engines in question what would be the differents in fuel is a 3.0 going to be mile more fuel usage
thanks for all your help

 

[Kawasaki]

anymore input welcome

Outboard

 

[moonraker 36]

o/b better power to weight.
inboard usually cheaper parts as they are car based.
3.0l in an 18ft'r don't expect much in the way of performance..

 

[Nautibusiness]

Outboard
Are we talking 2s or 4s?
Are we talking modern or old tech 2s?
Are we talking carbed 4s?

Are we talking carbed 3lt?
Are wetalking EFi or MPi 3lt?

An ultra modern 3.0Mpi is going to be better on fuel than an old technology 90Hp 2s.
But a carbed 3lt is going to guzzle fuel compared to a modern 4s.

A typical day to day 18ft bowrider with an off the shelf prop and 3.0lt inboard will struggle to break 36 knots or 40mph in Yank speak.
That said, a 90Hp O/B on a similar boat will probably just fall short of 34 knots at WOT.

Too many variables and you may struggle to get a reliable inboard at £4,500. I think you will be buying someones problems.
That said, a whizzy angling style boat with an O/B should be reasonable for about £4,500.

 

[Warpa]

o/b better power to weight.
inboard usually cheaper parts as they are car based.
3.0l in an 18ft'r don't expect much in the way of performance..

GPS speed on my 17.5' is 43MPH, so by no means slow and that was not WOT but at around 4300 RPM. Mines a 1997 bowrider and has no corrosion as it has always been well looked after. I prefer IB purely for asthetics reasons, the boat looks a lot cleaner on its lines.

I use about 20L a day unless going from Southampton to the IOW in what are normally rough conditions.

 

[ianmccabe3]

GPS speed on my 17.5' is 43MPH, so by no means slow and that was not WOT but at around 4300 RPM. Mines a 1997 bowrider and has no corrosion as it has always been well looked after. I prefer IB purely for asthetics reasons, the boat looks a lot cleaner on its lines.

I use about 20L a day unless going from Southampton to the IOW in what are normally rough conditions.

thanks for that
what make is it

 

[markcw]

Ok i had a mercury O/B 115 v6, and have to say what a f..k..g motor , power was unbelivable from start to 40 knots was no time, power to wait ratio was very good, noise was loud. but try and go slow and idle well that is another story, in a nut shell it didnt like it, fuel consumtion well yet again if your worried you wouldnt of run it. parts for it and serviceing very expensive, replaceing the impeller every year was a pain in the arse having to seperate the lower leg.

Now my volvo penta 3.0 4.3gl great love it to bits, you can go slow and chugg along a day, off the mark speed no where near the o/b i had, pulling power about the same, top speed is around 47knots on a 20,7 ft cuddy weighing in at 1700lbs, parts ok, filters choice is good from fram, and the yank brands or v/p, impeller is 6 little screws and can be done in 20 mins max and can be done at sea.

Sorry for me every time the Inboard will win just a pleasure to use and has many uses. and luckly for me i learnt to remove the engine from the boat becuase it a marinized car engine. to me boats look way way better when you cant see the engine on the back stuck out

mark

 

[Warpa]

thanks for that
what make is it

Its a maxum 1750 XR, service and winterise is around 200 quid and parts that dont really need to be replaced are done each year for piece of mind (impellor for example)

This is a vid of it at around 43 mph, this was with 6 adults, you can see the ski boats behind. It takes a while to get on plane with 6 up and i wound the speed up slowly as i like my engine Im hoping to get a wot run next weekend before i take it out of the water for the winter.

Work is under way on the boat at the moment, i have new maxum graphics for it and will be wetsanding for a mirror finish.

 

[Fire99]

Personally on the I/B front, I wouldn't be too concerned about the 3.0 and would even be tempted to go larger to a 4.3 etc on that sized boat.

The 3.0 will be working very hard and fuel consumption may actually be higher than a 4.3 or 5.0 running 2/3 throttle for the same performance.

 

[Warpa]

Personally on the I/B front, I wouldn't be too concerned about the 3.0 and would even be tempted to go larger to a 4.3 etc on that sized boat.

The 3.0 will be working very hard and fuel consumption may actually be higher than a 4.3 or 5.0 running 2/3 throttle for the same performance.

The 4.3 is what i would like and will have on my next boat, on a boat this size i have been informed it may upset the stability, and this thing is steady as a rock. Any of the mpi engines will be far more fuel efficient, but the OP's budget will not buy the engine let alone a boat to put it on, same goes for any OB.

The 3L is nicknamed the Iron Duke in the states from the car it was fitted to as its so strong and reliable Its also fitted as standard to larger boats, so the manufactures must think its capable.

 

[Fire99]

The 4.3 is what i would like and will have on my next boat, on a boat this size i have been informed it may upset the stability, and this thing is steady as a rock. Any of the mpi engines will be far more fuel efficient, but the OP's budget will not buy the engine let alone a boat to put it on, same goes for any OB.

The 3L is nicknamed the Iron Duke in the states from the car it was fitted to as its so strong and reliable Its also fitted as standard to larger boats, so the manufactures must think its capable.

Interesting stuff. Cheers for that. My point does still stand though that engine size and fuel efficiency aren't a direct one to one.

 

[ianmccabe3]

nice boat mate
i do like to idea of the inboard
i had a 4.3 v6 before and it was mad on fuel i needed a tanker behind me
i know some people say that if you ask about fuel u cant afford it
i know this but i want to go out and enjoy it and just stand and polish it
thanks for all the info so far

 

[tinkicker0]

I have a merc 3.0l on a 20 foot cuddy, so it's a bit heavier than the bowrider (especially with all the beer / tools / spare parts/ heaters/cookers/junk, I like to keep in the cuddy). Also run in freshwater, so it sits slightly deeper in the water anyway.

WOT is about 30 -32 knots at 4500 rpm. Drinks fuel.

1500 rpm / 6knots and the fuel consumption is around 5mpg.
2000 rpm and trying to lift and you can see the fuel gauge drop.
3500 rpm cruising speed and around 25 knots on the plane and the consumption returns to around 5mpg, although of course the quantity burned per hour is much greater.


The 3.0l is regarded as a very economical and durable engine, based on GM's Vortec industrial engines with different cam and pistons fitted. As someone said, the Vortec is very loosely based on the old 2.5ltr Iron Duke automotive motor fitted in the chevvy blazer and camaro.

http://www.boattest.com/Partners/Pa...54&t=BOAT-TEST&Videoid=434&p=0&s=#Test-Result

http://chicagoengines.com/industrial/gm30l-industrial-engine.html

 

[Warpa]

nice boat mate
i do like to idea of the inboard
i had a 4.3 v6 before and it was mad on fuel i needed a tanker behind me
i know some people say that if you ask about fuel u cant afford it
i know this but i want to go out and enjoy it and just stand and polish it
thanks for all the info so far

On an 18' you should be ok with the fuel like me, i have a SS prop that im yet to take off to see what pitch it is or whatever its called 20L a trip, and even if you dont go out just use a 20L jerry can with spout and top her up each week so its full, then a full tank will last a mont of weekend fun

I will top mine up every few weeks through winter when i pull it out of the water so i have a full service and full tank of fuel the day the sun comes out next year.