26M/X distance motoring. What is your range?

[ralphk]

Tangentair:
Thank you for reminding us of the factory guidelines.

I should have framed my motorsailing story with better context:
#1 Situation is about making a passage when the air is light. When my Mac reaches a 5+ knots under sail, I've got a giddy smile on, and my thoughts turn to raising engine not about burning gas. I want to reduce drag and feel the rudder feedback. (I'd really prefer a tiller at that point)
#2 There is a lot of open water. I would not try motorsailing near shipping channels or busy harbours.
#3 Ballast is full.
#4 My mindset when motorsailing, is that the skipper is SAILING.
#5 Additional thrust from the prop is really minimal. It overcomes the drag from the outboard plus adds a mild shove - probably no more than adding one or 1 - 1/2 knots.

#6 That the skipper is completely aware of point of sail and sail trim, and is experienced enough, to be able to anticipate forces causes broaching.
If they have a powerboat frame of reference; if they are just learning to sail, then observe the factory guidelines.

Hope this clarifies.


I don't mean to trivialize this but the factory has a safety interest in self preservation.
This is not unlike the tablesaw manufacturer that insists "Never remove the sawblade guard from the table."
An old cabinet maker I know, insisted that when in the hands of a skilled operator, table saws actually run safer without the blade guard.

[pokerrick1]

To answer the question: 2006 M, 60 HP E-Tec, two 12 gallon tanks - - - at 4,000 RPM's (my normal cruising speed) with mast up, about 75 to 85 MILES. At WOT I don't know - - - I never went two straight tank fulls at WOT. For me WOT is usually less than an hour in duration. WOT is also VERY tiring (and I'm an old guy).

Rick

[Terry]

I get about 4 hours running time at 3700 rpm on a 25 liter tank while towing my dinghy with the the engine on the transom. I can get better time without towing the dinghy as it requires an extra 200 -300 rpm to maintain the same speed. I have to travel at 3700 to keep up to someone else in a similar Mac at 3500 rpm without the dinghy. I too rarely use WOT because I am rarely in a hurry while cruising. I think about 3500 rpm (no towing) keeps me at about 8 knots of hull speed without lifting the bow so it is a fairly comfortable and fuel efficient speed.

On edit - Full Ballast

[Hamin' X]

Motor sailing with a Mac is no different than motor sailing in any other sailboat, as long as you remain at hull speed, or below and treat it as sailing. Just as in sailing, be aware of the apparent wind. The danger in a Mac would be when exceeding hull speed. As more of the hull rises out of the water, the boat becomes more top heavy, thus less stable and turns have a quicker response.

~Rich

[argonaut]

Do the mpg numbers reflect motoring with full or empty ballast?

[Duane Dunn, Allegro]

Mine are empty ballast numbers, however the hull speed one should be really close to the same with full ballast. Anything faster with full ballast and you will burn a lot more fuel than when empty.

[40Toes]

I find I get decent mileage with the 50hp Bigfoot. I decided to head to Dublin, Ireland from St. John’s Newfoundland for the weekend. I trailered the boat to the launch ramp and rigged the boat which took about 4 minutes and then provisioned her for the trip (loaded the cooler) which took another minute. I checked my fuel because I planned on motoring there because I wanted to be back in four days – one tank was empty but the other had 6 litres and after doing some quick math, I figured I had plenty besides if I took more fuel the extra weight it would slow me down. I left at 9am on Friday morning and as soon as I was clear of the jetty I was WOT (10000 rpm) ballast empty. At around the mid point across the Atlantic didn’t I hit a storm, 60 foot seas with winds gusting around 300 kts of course being prudent I reduced to half throttle – what a miserable way to spend a Saturday afternoon! I got through the storm in about two hours but not without mishap. I kept burying the boat and after surfacing after a particularly dreadful dunking I realized my GPS had been ripped clean off the boat. I found myself in quite the pickle as I didn’t have a backup and was forced to navigate by the stars alone which is not particularly easy in the day – luckily I had my day sextant with me. The rest of the voyage was uneventful except that I realized I wasn’t the navigator I thought I was – made landfall at some place called Brest! I didn’t understand a word they spoke so I used hand gestures to get fuel and replaced the 2 ½ litres I used on the trip over. I didn’t have the type of money he wanted and the guy was insistent on taking my helm as payment as he kept pointing at it – I guess he liked the way it shone in the Sunday morning light. Anyways like a fool I gave to him and had to attach a pair of vice grips to the stem so I could steer. You could imagine how perturbed I was at this point having missed Ireland altogether and landed in some god forsaken concrete wasteland so I said the heck with it and decided to head home. I found the star directly above Newfoundland and headed home. Although it was a pain and very tiring to steer with a pair of vice grips I was home by suppertime Monday night. I was totally bagged after only getting 12 hours sleep the whole weekend. Fortunately, other then being swallowed whole by a whale on the way back (story for another time) as I find I am rambling, the voyage was uneventful. Yeah, so basically I get decent mileage on my motor – going fishing this week and can’t wait to see what I catch….

[SkiDeep2001]

Or what catches you. You never know what lurks in the deep. Nice yarn

[Matt19020]

From my expierience I found the following:
Click on Pic to enlarge...and again to enlarge more...
One day I had time to kill so I went out and recorded the following:
I have A Suzuki 70 with full ballast in My MacM and recorded the following with a Lowrance GPS and wiring harness connected to the module on the motor to measure fuel usage at the injectors...
I wanted to do a chart but I could not figure it out how to work Excel so this will have to do....

[Lieu Daze]

Hey Ralphk...I was in the process of getting a handle on range for some trips this summer. Left Whitby marina this weekend for Centre Island. As usual...when you need it...not a lick of wind either there or back Sunday so motored both ways.

For comparison.... ", 60hp Merc 4 stroke, cruising about 6.5 - 7 kns, moderate load of cooler, 3 people, standard amount of liquid rations. Ballast empty on way there, full on return while praying for wind, and not much difference either way. Burned a 6 gallon tank each direction of 22.7 NM. Also no appreciable difference with some dagger and a rudder down as outbound everything was raised but coming back I got tired of fighting the wander and dropped them to relax at the steering.

Obviously a huge difference when you put the hammer down. Same weekend last year we left late....in jeapardy of not getting a spot on the wall at Hanlan's....pushed it full and ended changing tanks just past Bluffer's at about 17 NM.

JR

[ralphk]

JR.

Thanks for the post.
Interesting, I change a 24l tank between Bluffers and Ashbridges Bay, at 5400 RPM.
Going east, at the moth-balled coal power plant, two-thirds of the way to Cobourg.

I think I saw you last Tuesday evening. (White covers or purple?)
BTW, I wasn't on the Mac - I bought a guy toy earlier this spring.

It's a single-handed racing dinghy, based on an Auzzie skiff, called MX-Ray.
Red hull, Mylar sail and an assymetrical spinnaker - all in a 120 pound package!

It's been a great rush - two actually, the first is just wrestling my 40+ carcass into an old, too small wetsuit.

If you've got time, checkout
http://www.youtube.com/watch?v=3jHC9_GkeRQ (DEFINITELY NOT A VIDEO OF ME AND THE WETSUIT)


Ralph k.

PS
Good french fries at Bluffers - keeps the kiddies content.
pm me, if you'd care for a tandem sail one evening.