Diesel / Petrol ? in a 22ft boat

[Happy1]

Hi Tico, info appreciated, but see my last thread, it explains my problem. cheers.

<hr width=100% size=1><font color=purple> "You only see what you recognise, and you only recognise what you know" <font color=purple>

 

[Happy1]

Haydn? He is a nice experienced guy really I think, under that hard 'Up North' face he puts on /forums/images/icons/laugh.gif

<hr width=100% size=1><font color=purple> "You only see what you recognise, and you only recognise what you know" <font color=purple>

 

[BarryH]

Can we kill this myth that petrols are rendered useless at the first hint of water. Lets face it if an engine gets that wet where the water is going to stop it then theres going to be a hell of a lot of water in the boat. If theres that much water in any boat be it petrol or diesel then I think the least of your worries is if its going to run or not.

Its all down to the owners. The electics on my boat are semi protected. All done by me. I've used tips from my days of running rally cars. A rubber glove with zip ties makes a brilliant dizzy cover to keep out the water. A liberal spraying of duck oil on the rest of it takes care of that.

Diesels, most of the new genration diesels that we're talking about have a little box of electrickery to sort out fuel metering air flow etc etc. So the engine will rely on leccy power as much as the petrol engine. Yas I know your going to say ah but it was designed for it. Well so's the leccy stuff on most petrol engines. Probably why a new Bosch dizzy cap for my engine worked out at around 40 quid when the car one comes in at under 14 quid.

I've had my engine running with a water leak from the raw water pump. The first I knew of it was that the bilge pumps kicked in. I lifted the cover. The engine ,including the leccy bit was covered in water that was being picked up by the belts and being flung everywhere.
Ok in the "olden" days when things were a bit more basic that could have stopped the engine but this one kept running for another 30 mins until I reached a place to stop and sort it.

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[gjgm]

Re: alistaiir fuel consump.

Sorry, there is no way you are combining those fuel and speed figs properly. If you look at boattest.com, they have 8.4usdgallsp/h at 3000revs, which is about 26mph.40 mph will push you up to 13 imp gph.
If you are getting those fuel figs, you need about 1500revs and 7mph.
Thats not the same as saying you are not spending that amount of fuel for your day out, but that your engine efficiency is not as you claim. Just about possible with a 3.0l 18ft boat. Very roughly, 3.1l is 3-5 galls, 4.3 l is 5-7 galls and 5.0 is 7-10 gals, all very subject to sea conditions,load,use of throttle. But it s a realistic benchmark.
But as long as you are happy, doesnt matter !!

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[BrendanS]

As Kim has commented previously, the idea that American boats are designed for flat lakes is a myth.

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[hlb]

Probably it's not a question of who's right and who's wrong. Boats vary wildly on fuel usage dependant on location and what one does in the day. Suppose best check would be to fill up, cruise to CI and fill up again, without dilly dallying about.

I work on MPG and recon it does 1.3 MPH on a long run. Constant 18-20 knots to say Guernsey. Thats the only time it's important to know. Else maybe not get there!! But messing round Plymouth sound, Flat out stop, flat out stop. It might do half that. On the other hand, when up the River Severn. Only used Quarter tank over 100++ miles over six months. The eberspacher used more fuel than the boat!!

Most folk use GPH or MPH at constant cruising speed. To determin range, not cost. But I suppose with smaller petrol boats just bobing round Solent, range is not so important, but maybe cost is. So different Figgers.

<hr width=100% size=1> <font color=blue>No one can force me to come here.<font color=red> I'm a volunteer!!.<font color=blue>

Haydn

 

[Alistairr]

Re: alistaiir fuel consump.

I don't understand it either, 3 people have confirmed it ,Myself, the Mechanic, And the Marina manager that looks after my fueling.

Am i right in the way i work out the GPH?

But hey, Who cares? I'll still enjoy my boat no matter what!!!!

However i may look into it./forums/images/icons/smile.gif



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[tico]

Sorry OOps, I meant to exclude some eg Formula or Donzi, but, lets be honest, SOME US boats have very low deadrise to give easy planing but at the expense of seaworthyness.

<hr width=100% size=1>Been there, done that, got the oily T shirt

 

[gjgm]

Re: alistaiir fuel consump.

well,there arent too many numbers in the equation. Assuming that your fuel estimate is correct, then your hours must be wrong. Your electronics may say 7 hours, but i dont know whether thats engine running, or battery isolators on . Neither is it so easy to calc how much time is at tic over, anchoring,berthings etc, which will distort your numbers. I also thought I was getting some very pleasing consumption figures, but when I started longer (and so more reliable for this case)runs, the figures came out alot higher. i think the boattest pages are pretty fair.You could have a check on hours times avg cruise speed, and see if that makes any sense regarding the implied distance you have travelled. It probably doesnt. In your case its about 150 miles?

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[adarcy]

Re: alistaiir

I hate to sound pompous or teach grannies to suck eggs, but it doen's stop me - here goes

I think you are (correctly) calculating GPH of switch-on time and others are talking about GPH whlst cruising in order to work out their safe fuel range.

Of your 7 hours "sail" time, how much of it is with the ignition on whilst the fan blowers work (zero GPH) idling to warm/get out from mooring (v good GPH but not MPG) trogging out to the speed limit (excellent GPH and good MPG) and then how much left for cruising time when most of the petrol is consumed for the day (may be good MPG on the plane but much more GPH).

Newer generation EFI petrols have closed the gap on diesels when running at idle and v low throttle settings but, as a comparison. I well remember looking at the figures for a diesel Portofino 32 which did approx 1.5 MPG at 32 knots and 8 MPG at 6 knots. = 31 GPH v 0.75 GPH. For us a day out on the Solent may well involve 15-20 mins idle out and down the river 20 mins blast to Cowes/Newtown/wherever and say 10 mins idle to tie up or anchor. My switch on time GPH on such a boat would be around 15 GPH but IF we planned a fast trip (obviously not flat out all the time) I would be cautious enough to calculate nearly 30 GPH.

Sorry if it is all so obvious but I think people are disagreeing because they are not talking about the same thing.

Anthony

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[burgundyben]

Re: alistaiir

Yep, youre dead right.

If I took my old Huntress to Cowes bimble down the river, blast across to Cowes, moor up, took and hour (was moored up top near Col and Solitaire), boat would use about 4 gallons a trip, but thats not 4 gallons per hour in the true sense.

On a constant run at say 15% below max (27 knots) speed consumption would be 8 gallons and hour.

<hr width=100% size=1>Sod the Healey - I think I'll buy an E-Type.

 

[kimhollamby]

Ah, but be careful here

Being pedantic Nelsons have close to zero deadrise at the stern, just like the Carvers you were talking about in an earlier post!

There's a lot of boats that some people think are very seaworthy that are if used within design limits but can be a handful if re-engined or powerful and pushed too hard in wrong conditions.

I'd be happy to take many of the flat-bottomed American motorboats out in rougher conditions...most are actually not flat at all where it counts up towards the front and some of them in fact have quite sea-kindly forward sections...but I wouldn't push them hard downwind in the way that you can a more modern Olesinski Fairline or Princess or a Shead Sunseeker or for that matter a Sealine F36/F37, on which I have made some great downwind passages. Mind you, I'm not sure I'd push an over-engined Nelson hard downwind either.

The trade-off is interesting -- useful economic performance up to the mid/high teens and often not much of a hump to overcome versus the out and out performance of a medium to deep vee warped bottom.

Sorry but the reality if that tired old saying...the crew gives up before the boat...is true for the majority of what is out there to buy.

None of that is to say that there aren't better boats than others; but capabilities of many of them usually sit well inside expectations of anticipated weather.

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[duncan]

I would just like to mention coils at this point...............

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[BarryH]

If I new what you was on about I'd probably come back wiv a whitty answer. Bit seeingas I've just been kicked out of the pub at 10 oclock and I havent a clue as to waht your on about. I wont.
Oh I won the pool by the way. Somehow I don't think I'll be getting away at 6 in the morning.

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[BarryH]

Oh yeas, just rememenbered That was a faulty part nothing to do with watere on the eklectric bits.

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[BrendanS]

<shudderr>

I prefer to keep things in my control
Condoms!!

Eek! did you mean something elese.

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[stamfordian]

i havn,t read all of the replts and i.am pissed but personally you must be joking,,buy a bigger boat you obliousky have loads of cash so stop prigging around with a brand new boat,cash it in aaand get a boat you really wont,i.am not beieng vindictive but tyoou must admit you have spent a reasonable a mount of money on a boat ,only to tear it apart and make it into something else.....b****y mad enjoy what you have ......a diesel might sink it¬!!!

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[Happy1]

If a diesel is £9.3k more than a petrol, who in their right mind would pay even more for a diesel second hand when they could still get a brand spanking new petrol, latest model cheaper? That's my concern /forums/images/icons/wink.gif

<hr width=100% size=1><font color=purple> "You only see what you recognise, and you only recognise what you know" <font color=purple>

 

[Happy1]

I can't agree with you here as it is P v D, I have the option to go D, but at great expense. What concerns me is the difference, it would make the boat almost unsaleable secondhand when a brand new petrol would be available much cheaper. If the petrol was not any cheaper I would want to know where my extra investment of £9.3k on the D had gone /forums/images/icons/wink.gif You have to use a hell of a LOT of P to cover that loss /forums/images/icons/wink.gif

<hr width=100% size=1><font color=purple> "You only see what you recognise, and you only recognise what you know" <font color=purple>

 

[Jim44]

Why don't you buy the Sealine S23, great looking boat available in Diesel you can trailer it and I believe that Sealine offer a buy back guarantee (the price you pay) on the diesel, if you trade up to a bigger Sealine, so you will not lose anything



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