Inboard fuel tank?

[kadet]

I am in the process of preping the for some long haul live-aboard adventures. One of the mods I am considering is fitting some longer range fuel tanks.

Option 1 the one I am considering is to fit a custom alloy tank 100L (25 Gallon) inboard under the rear berth.
Option 2 is to fit 4x22L (6 Gallon) tanks in the cockpit, the one I'll go with if not the inboard.
Option 3 is to fit 2x45L (12 Gallon) tanks in the cockpit, only if I cannot get 22s that will fit 4, my current 22s only fit 2 in the available cockpit space.

I am steering towards 1 mainly because as I am concerned about the weight high in the rear making the less stable in a following sea.

Alloy tank is not going to be cheap and I would rather spend the $$$ on other toys

To those that have the dual 45s or quad 22s is the weight an issue?

Any other suggestion welcome.

Thanks

[yukonbob]

My first option would be a tank up front in the v foam area or if you're worried about buoyancy maybe two smaller tanks on each side of the vent bowl, but you'll loose that as a storage area. His would help balance our boat better as we are art heavy. It would be some work running the fuel line back and a deck mount fill cap but it'd be hard to beat IMO. I think I remember someone getting 12-15 gallons up there ??
And ya that's with twin 12 gallon tanks in the cockpit.

[yukonbob]

re read your post. I would go for the front tank with the twin 12s in the back. With the two 12's and a couple of 6.6g jerrys we get about a 120nm range at 3000-3500 rpm (incl 20' tides and 2-3knt current.

[kadet]

Water tank already in V-Berth old foam area but thanks for the suggestion.
I was going to put a couple jerry cans of 2-stroke in the V-Berth storage area for dingy and generator as they are both smoke blowers .

[kadet]

re read your post. I would go for the front tank with the twin 12s in the back. With the two 12's and a couple of 6.6g jerrys we get about a 120nm range at 3000-3500 rpm (incl 20' tides and 2-3knt current.

What speed you making at that RPM?

I was going to sit on about 2000RPM which gives me about 4-5knots and uses a bit over 1/2 a litre per nautical mile on a flat sea with no current. Longest leg is 110NM so was hoping if needed I could motor there and still have enough fuel to play before needing a refill for the return journey. The plan of cause is to sail but options are nice.

[Mac26Mpaul]

Kadet, I have 4 x 22litres. I think its a better option than the 2 x 45Litre ones, because I can take the tanks out of the boat to fill them when the need arises. This came in handy in a Servo where it wasn't appropriate to try and tow the boat up to the bowser in a small country servo. Another time it came in handy was when I almost ran out of fuel on the water (yeah, poor planning), and had to anchor and took one of the 22 litre tanks to a Servo in my dinghy. As you know, fuel points on the water can be few and far between around here. Also, I can leave a couple of tanks at home when just doing local trips which gives me storage room in the fuel lockers.


There was a thread somewhere here were I posted pics, but yeah, the cheap ones at whitworths fit perfectly side by side in the M fuel locker.

Are you talking about Whitsundays cruising? We are hoping to get up there next year.. What I'd really like to do is sail my M from the Gold Coast to the Whitsundays. Just have a few problems, my family will not be in a long bouncy sea voyage, plus I cant afford to take the time off work (plus I don't have an autopilot which would be a necessity..).

[kadet]

Hey Mac26MPaul,
4x22Ls is looking like the easiest option. How does she handle with all the weight in cockpit though? Yeah 4 Whitworths 22L hulks look like they will fit perfectly.

Plan is next year to do Brisbane to Frazer. Which is a a test trip for Brisbane to Lady Musgrave. Then if all goes well Brisbane to Whitsunday in the future.

Wife hates sailing gets sea sick, lucky an old school friend loves sailing the rougher the better so she has been designated the boat wife

This dude does it in a 20 footer and is kind of who got me thinking about it

https://www.youtube.com/channel/UCfFF_e ... BK34DGfIZg

[kurz]

I deal with a 25L outboard tank, then squesed a 10l tank next to it, that ist filled with spiritus. Could also put another 1 or 2 10l tanks behind the outboard tank.

On the other side in the cockpit a store 4 tanks of 10liter. This is quite good for me as I get the fuel normally from the petrol stations on the road, so the handling is easy! And as all the tanks are white I can allways see if they are full.

[Russ]

I am in the process of preping the for some long haul live-aboard adventures. One of the mods I am considering is fitting some longer range fuel tanks.

Option 1 the one I am considering is to fit a custom alloy tank 100L (25 Gallon) inboard under the rear berth.
Option 2 is to fit 4x22L (6 Gallon) tanks in the cockpit, the one I'll go with if not the inboard.
Option 3 is to fit 2x45L (12 Gallon) tanks in the cockpit, only if I cannot get 22s that will fit 4, my current 22s only fit 2 in the available cockpit space.

I think #1 is the most ideal. Get fuel and weight low and use space that is hardly used anyway.
It's also most expensive and complicated. You'll want to install a blower (not a big deal) and custom build the tank and fuel filters.

We have 2x45L tanks in the cockpit lockers. Performance is not an issue, however the weight is. Heavy 70HP motor + 24gals of fuel plus crew, the aft is heavy. If I had to have the weight there anyway, I'd rather have it lower and use the cockpit lockers for gear.

Paul does make a valid point about smaller portable tanks. The ability to fuel them off the boat might be important in your decision. Even 22L tanks are heavy and not the ideal to be muscling them on the boat every time. However if it's your only option, it might save your butt some day if marina fuel docks are not an option.

--Russ

--Russ

[BOAT]

Water tank already in V-Berth old foam area but thanks for the suggestion..

You mean TANKS FOR THE SUGGESTION ! ? (okay, ha ha lame joke)

[BOAT]

With the two 12's and a couple of 6.6g jerrys we get about a 120nm range at 3000-3500 rpm

So that's 36 gallons for 120 miles equals 3 miles per gallon, have I got that right? Is that normal? I was getting a little more at WOT.

I thought the cruising MPG for the MAC was 4 to 5 MPG?

Someone check my numbers - I must be wrong
Is this wrong?:

RANGE UNDER POWER
Max range, low speed 283 miles at 6 mph
Max range, cruise 115 miles at 16 mph
Max range, full speed 84 miles at 21 mph


MILES PER GALLON
Miles per gallon at low speed 11.8 mpg at 6 mph
Miles per gallon at cruise 4.8 mpg at 16 mph
Miles per gallon at full speed 3.5 mpg at 21 mph


FUEL USE
Fuel flow at low speed:Gallons per hour .5 gallons at 6 mph
Fuel flow at cruise:Gallons per hour 3.2 gallons at 16 mph
Fuel flow at high speed:Gallons per hour 6.0 gallons at 21 mph

[kmclemore]

You might want to see a previous discussion on this, here:

http://www.macgregorsailors.com/forum/v ... 796#p96796

[BOAT]

Too dangerous to bring gasoline into the cabin. Scary

You guys really travel that far on gasoline huh? wow.

[kadet]

Too dangerous to bring gasoline into the cabin. Scary

You guys really travel that far on gasoline huh? wow.

You mean like every inboard power boat out there

No the plan is to sail but if the wind won't play I am not going to float around for 3-4 days or tack for a 100 miles into a headwind

[kadet]

I know an internal tank is possible, I am not concerned about the hook up or danger just is it necessary is the weight saving high in the cockpit important or does moving the weight lower in the back really not make that big a difference?

I suppose I can always go for 4 tanks in the cockpit then if I find the weight is an issue worry about an internal tank later. Just with the number of members here with twin 12 gallon tanks I thought they might have some experience and advice on the weight up top.

A custom tank is going to run close to a boat buck so 4 little ones for a couple of hundred is a nice $$$ incentive to not go that route but is a waste if I end up having to go internal in the long run.

Decisions Decisions