Fuel Consumption

[RobWheatley]

I have just bought a 1966 Dell Quay Ranger 27 fitted with twin Volvo Penta AQ140's petrols and 280 drives, looking to re-engine her with diesels over the winter and was wondering about fuel consumption.

Im looking at different engines to fit (will be car engines marinised) in particular the 1.9 or 2.1 citroen turbo diesel (90 & 110hp), the 2.5 TD citroen (130hp) or the 2.8 TD Isuzu Trooper (106hp) all easy and cheap to obtain and all have a rev range of about 4-4500 rpm.

I have a 2.1TD Citroen car at the moment and get about 48ish to the gallon loaded at fast motorway speeds using about 2 gallons an hour at 3500 revs, now i know that loads on a car are different to boats but how much more would i expect to burn with them fitted to my Dell Quay, would a guestimate of about 6 gallons an hour for the pair at 3500 rpm not be too far off or would it be more than that, she is about 2 1/2 to 3 tonnes and a planing hull.
Lancing marine recomend the Ford 1.8TD escort engine but this would be too under powered at only 70hp each as im looking at the original engines having 140hp each.

Am i correct in thinking that i need the same hp with diesels compared to petrols or can i have less hp if they produce more torque.

What i dont want to do is end up with too big an engine in her that is wasted (though i have seen that with twin 5 litre V8's the dell quays would do 46knts) or ones that are too small and a WOT all the time.
Thanks
Rob

 

[[2068]]

> i need the same hp with diesels compared to petrols or can i have less hp if they produce more torque.

You'll need the the same hp if it's top speed you're after, but for cruising, you can get away with less hp to get planing and cruise, as mid-range torque is better with the diesel.

I'd have thought something equivalent to two Volvo D3-130's would fit the bill. Or D3-160's if you wanted to fly.

I would guess 6-7 gals an hour for a pair of 130's. Maybe 8-9 gals an hour for the 160's at a faster cruise, probably closer to the 130's if you slow down.

dv.

 

[Kawasaki]

Have a look at Fairy owners sight.
Or google dellquay rangers .
Apparently there are about 17 of them based in Guernsey still.
Look quite a classic always fancied one. never brave enough.
Every time I've bought a "CLASSIC" turned out to be a classic mistake! /forums/images/graemlins/frown.gif
Diesel replacement seems the sensible route to go.
Safety + economy. Then again there are those that will point out that maybe we will be paying white diesel money some day.
Then again if depends in which part of the UK you will be boating(stick a few more details in your profile if you don't mind) cos if it's like My area there are not many places were petrol is available alongside.
Good luck and welcome to this Forai of weird and Wionderfull peeps and info. /forums/images/graemlins/cool.gif

 

[Ifraser]

I think Rob seems to be keen to use car engines, probably for price reasons...I'm just about to re-engine my 26' cruiser that has the same engines as Robs with a pair of the mercruiser 1.7diesels. Hp is almost the same as the volvo petrols....Iain

 

[RobWheatley]

Yes car engines are the way im going, way out of my price range to use pukka marine engines, besides most marine engines are car engines, the AQ140's are out of volvo 244 cars!! Perkins Prima M80 is Montego's etc.

Well She is a classic, 40 years old, same as me!!! and in need of some TLC, removed the fuel tank (100 gallon) and water tank (50 gallon) at the weekend and the hull needs repairs underneath where the old shower drained direct into the bilge and was not pumped out enough, can see the tide mark up the bulkhead for the soap scum, lovely but apart from that and a few patches the hull is good.
Regards
Rob

 

[[2068]]

That's fine. I did say "equivalent to" /forums/images/graemlins/smile.gif

dv.

 

[alb40]

If your thinking of using escort TD engines, then make sure you get the intercooled version. These are 90hp units, whereas the non intercooled are 75hp.

Alternatively, if these aren't powerful enough, you could use the ford 2.5di turbocharged engines. These give 130 - 140hp and would mean it would probably go better than the original units. There not so easy to get second hand as the 1.8 units though.

My escort has the 90hp diesel fitted, and can return 50 - 60mpg, even in town. Its on 130k now, and runs like new still.

 

[neale]

[ QUOTE ]
> i need the same hp with diesels compared to petrols or can i have less hp if they produce more torque.

You'll need the the same hp if it's top speed you're after, but for cruising, you can get away with less hp to get planing and cruise, as mid-range torque is better with the diesel.

[/ QUOTE ]

I wert through this same thought process when I changed from Petrol to Diesel and the results proved otherwise.

24ft Bayliner originally fitted with 230hp V8 petrol. Top speed according to brochure 35mph (30.4 knots). Fitted a Volvo KAD32 producing 170hp. Top speed now 30 knots.

I do now have duo prop rather than single, so this may have helped a bit.

 

[[2068]]

Think it depends on the boat.

With a light, high performance boat (i.e. overpowered) the petrol is going to have the edge. 230hp is 230hp is 230hp, whether produced by petrol, diesel, paraffin, or chip fat. With a heavier cruiser, the limiting factor is getting planing, so you probably end up propping down with the petrol to get planing and lose the top end.

Those KAD32's have got wodges of mid-range grunt cos of the Superchargers, and I've heard rumours that they produce more than 170hp at the top end too. Add in Duoprops, all of which makes it an unfair race /forums/images/graemlins/smile.gif

dv.