DSK wrote:

Capt. JG wrote:

I for one have no interest in owning a 26 foot boat that comes with
a 70hp engine. This is the antithesis of what sailing is all about.


I wouldn't mind having a 70hp engine in our 36 foot boat


JimC wrote:

The boat is built to be balanced in the water with crew and with an
outboard of 50 - 70 hp. If the moter were removed, the boat would
tend to "lean" forwardly, with the stern too high in the water. The
weight of the outboard is far less than the weight of a typical
diesel in a 27-29



In other words, the boat is ballasted with a lot of mass far forward, as
Jeff was contending earlier.

I never stated that the ballast mass is "far forward", DSK, and I don't
think Jeff did either. As to the moment of inertia during pitching, the
motor, after all, is about the same weight as a crew member, and though
its slightly aft of the cockpit, its weight (mass) is not a great
factor, as some of your buddies claim. (As previously stated: "I doubt
seriously that the weight of the motor is a major factor.")


Jeff wrote:

Not really. A 50 Hp 4-stroke weighs over 200 pounds - Honda claims
the lightest at about 210, Suzuki's is about 250. A Yanmar 2YM15 is
249 with transmission, though the shaft and prop is extra. There
really isn't a lot of difference in weight.


Big difference in efficiency, though.


ft boat, although, of course, the weight of the diesel is better
positioned.



There is a huge difference here. In fact, much of the weight of a
diesel could be considered ballast. At the very least, it contributes
little to the pitch moment.


Between the ballast far forward and the engine wieght far aft, it's hard
to imagine a worse set-up for good sailing performance.


Actually, of course, the ballast is centered only slightly forward of
amidships, as we have already discussed. The motor, weighing only 200 -
250 lb., is of little consequence.


The chief disadvantage of the larger engine is that it gives
Mac-bashers who have never sailed a 26M another opportunity to turn
their noses up at Mac owners. Although the Macs don't point as well
as conventional boats with weighted keels,


Does the weight of the keel affect pointing? Funny, I always thought
that had to do with the basic rig design... aspect ratio, sheeting base,
etc etc... keel foil configuration plays into it somewhat I'm sure, but
how does the wind know (and why would it care) about the weight of the
keel?

As you probably know, a weighted keel positioned five or six feet below
the hull entails more leverage and provides a more efficient righting
moment than the same weight of ballast,particularly water ballast,
positioned within the hull. For its size, it a deep, weighted keel is
more efficient in keeping the boat in a nearly upright position as winds
increase, permitting more efficient translation of the force of the wind
into forwardly directioned forces. The aspect ration of the keel is, of
course, also a factor in preventing lateral "sliding" of the boat, and
the Mac 26M has a retractable dagger board that is quite narrow. To
compensate for the relative inefficiency of the water ballast as
compared with a heavy,weighted keel, the Mac has a total ballast
sufficiently large to keep the boat upright. After years of mods and
improvements, the current model, with appropriate reefing, sails ratehr
well in pretty heavy weather. (For example, mine was heeling at only 20
degrees Saturday in 15 knot winds, with the first reef taken in.)


Are you tacitly admitting that Mac-26Ms don't sail to windward very
well? We already know that's true of the M26X.

No I'm not tacitly admitting anything. I'm openly stating (once again)
that they don't sail to windward as well as conventional sailboats with
weighted keels. It's one of the compromises of the particular design.



... I doubt seriously that the weight of the motor is a major factor.


OTOH those of us who have been rigorously schooled to sail *well* have
been taught to keep weight out of the ends of the boat. Any one design
racer will have seen (if he's paid the slightest attention) a boat with
crew sitting spread fore & aft getting passed by a boat with two guys
sitting close together.

I'll remember that the next time I'm racing, DSK. But actually, I didn't
buy the Mac with that in mind. I bought it to enjoy the overall sailing
experience.


... Rather, it's the compromises relating to the internal ballast,
trailerable hull, and lack of weighted keel. (The metactric effect.)



Please explain. I know about metacentric height, but have never heard of
"the metacentric effect."

The metacentric height is considered the distance between the center of
gravity and the metacenter. By "metacentric effect", I was referring to
the fact that the righting force is proportional to the metacentric
height times the sine of the angle of heel. Thus, a conventional boat,
with weighted keel low in the water, would have a lower center of
gravity than the Mac and would therefor tend to be less tender. Again,
the Mac 26M does entail compromises, but after a number of years of
development and modifications, it does the job. (If it didn't, I would
have capsized Saturday in the 15-knot winds instead of sailing along
with a 20 degree heel.- Right?

Jeff wrote:

Actually, the engine by itself doesn't bother me that much. I think
that if you asked detractors if they would accept an engine with 3
time the power if there was no cost in weight, fuel usage, initial or
maintenance costs, etc., most would take it.


Sure. Why not? I'm not sure there's any way to seperate the added
horsepower from the added speed & fuel usage though.


... The problem is that most hulls are designed for sailing, not
powering at high speed. The Mac made a number of compromises - a
flat "powerboat" hull, no external ballast, that greatly diminish its
sailing ability.


Ever seen the hull of an 18-footer skiff? They are very wide & flat aft.
Of course, they are *also* designed to generate significant amounts of
horsepower from their rig, and can plane readily. The Mac26-M is not and
can not.

No, the 2M isn't flat aft. Instead, as can be readily seen from looking
at the stern, it has a pronounced V-shape, which extends from the stern
to amidships. In contrast with your statement, it does plane easily and
smoothly. And it's also a lot of fun to sail.


My boat actually could accept large engines - the builder put twin
100's into the smaller version of it, and with only minor hull mods,
created a best selling powercat. But this formula does not work well
for monohulls.


I'm not so sure it can't... I am sure that it can't be done both well
and for cheap. A smallish motorsailer that had very good sailing
performance might be quite a nice boat, but it would look more like a
Melges 24 than a Mac26-M.



The more important factor, however, is that they are lots of fun to
sail.



So you say. Why is it that you almost never post a trip report?


Maybe he's too busy having fun?

Frankly, I have had a good time sailing two shipping pallets skinned
with roofing paper & a bedsheet sail. It was like a really cheap little
scow. So I can believe that Jim enjoys sailing his Mac26-M. However I am
not spending the rest of my life boasting about what super-dooper hot
performing sailing machine that 1-hour scavenged scow was.


And just where did I say that the Mac 26M is a "sooper-dooper hot
performing sailing machine", or anything of the kind? I've said that the
Mac 26M is fun to sail, but I have consistently stated that it doesn't
sail or point as well as a large displacement boat. Instead of saying
the Mac is a great sailing machine, I've said that it has limitations
and disadvantages when compared with conventional vessels.

Do you consider lying about what I said, as you just did, a necessary
evil acceptable when convenient, DSK? Do you consider it appropriate to
ignore any principles of ethics because, after all, you are merely
involved in some more Mac-Bashing, apparently for the amusement and
"atta-boys" of your buddies? Do you have no self-respect whatsoever, DSK?

Jim