Re-powering a MacM from 70 HP up

[beene]

Dude..... move away from the snow belt region will ya!

In T.O. nothing but rain to wash away all the dirt of winter.

Snow is all but gone J.

G

[dlandersson]

I would LOVE to cruise the Aegean. One class I teach/have taught is "Greece (Sparta really) and the Ancient World". Love to see the cradle of western civilization.

Thanks dlandersson. You know, the Turkish coastline is very nice but Turkey is another country, on the other side of the Aegean Sea. Check out this website as an example of what I have in my back yard here in Greece, http://www.poros.com.gr
The beautiful island of Poros is a fine example of one of 3.500 Greek islands we have scattered around the Grecian Archipelago.
GREECE really is a sailor's paradise.
'GO GREECE'!!! (in a Mac )

Octaman

[Octaman]

MacM + 1950cc = HUGE success

New observation!

We had good weather this weekend so went out on the Mac.
Not just powering but also sailing as the weather was ideal.
My new observation is that, in fact, I feel the Mac sails better with the heavier outboard; she is not as sensitive to rounding up when going upwind with excessive canvas up. The logical explanation is that with the heavier engine all the way aft, the centre of gravity has moved slightly aft as well contributing to this advantageous behaviour.
It’s not a big difference, but there certainly seems to be an improvement.

Octaman

[ROAD Soldier]

MacM + 1950cc = HUGE success

New observation!

We had good weather this weekend so went out on the Mac.
Not just powering but also sailing as the weather was ideal.
My new observation is that, in fact, I feel the Mac sails better with the heavier outboard; she is not as sensitive to rounding up when going upwind with excessive canvas up. The logical explanation is that with the heavier engine all the way aft, the centre of gravity has moved slightly aft as well contributing to this advantageous behaviour.
It’s not a big difference, but there certainly seems to be an improvement.

Octaman

That would be correct on any sailboat the more weight aft the less the boat has a tendendcy to weather up. Now you are ready for a 2 headsail setup.

[Octaman]

MacM + 1950cc = HUGE success

Nah! 2 headsail setup is not for me. That's Highlander's department. I pefer to keep it simple as I sail single handed most of the time.
What I will do when the budget is in place and this will be my next serious investment in our Mac, is get a new set of good performance sails for the existing sailplan- the stock sails are really very basic. The Mac needs a set of well thought out, well measured, well cut 'shallow' sails to reduce heel and increase speed a little. But I'm not ready for this now. There are several members on this site that have gone down this road with impressive resluts; delevi is one. The 'Black Pearl' is another.
I guess the stock sails have served us well enough all these years - can't complain.

Octaman

[beene]

You will notice a huge improvement going from a blown out main to a high performance one, when beating upwind.

You will be able to point higher, and go faster.

G

[Octaman]

MacM + 1950cc = HUGE success

Hey beene,

Now that I am completely covered and extremely satisfied with 1950cc on my stern I can concentrate more on sails. I would be very interested to know what sails you have on your macM and their characteristics. Any info would be appreciated. Nice to hear from you that there is an improvement in performance.
I guess I could start a new thread with this topic but "Repowering a MacM from 70hp up" is still very much alive and active as I have an undertaken an obligation to povide a video taken from another boat of my runnning, so that everyone can see what she looks like with 1950cc pushing effortlessly and rapidly forward!

I also have one other point to bring up. I have noticed that I do get an odd slosh of water coming up the keel trunk more often than before the new outboard (I recall Stefan had the same issue with his M and the 1500cc/90). Even when I trim the level of the bottom end of the keel to slightly extrude beyond the hull. And, yes, it is annoying although in essence it is not that much to create a concern. It is the extra speed gained that creates this spurt of water every now and then. But I like to keep the coachroof dry. I have been thinking of a remedy for this; perhaps a flexible piece of rubber screwed on to the top of the keel, like a flange, just enough to deflect the rising water and stop it from coming out of the top. Any other ideas?
Do you face this behaviour with your Mercury when speeding in the high end?

Octaman

[Octaman]

MacM + 1950cc = HUGE success

Yes, I do have the transom wedge in place, beene.
Thanks for all this info on the sails and all the links. Did some great reading. All very valuable.
Leon (delevi) has always been very good with his postings - and a good sailor. I think we have all learnt something from them.

Weather not so good this weekend - didn't go out on the boat. Have to wait till next weekend

Octaman

[beene]

Having a hard time feeling sorry for you when you say you have not been out, today......

LOL

I have not been out since Sept....



I wont be out till maybe June..... maybe.....





So enjoy her when and while you can.

Cheers

G

[Octaman]

One summer season later, I confirm: MacM + 1950cc = HUGE success

---------------

Hi to all you wonderful Mac owners worldwide.

I’m back on the forum after a great summer season with many mac tales to tell.

The main message I want to relay with this posting is that the engine upgrade to a Suzuki 100 hp/1.950 cc that has been discussed extensively has exceeded all expectations.

So, this is just to let you know that after 2 full months of messing around on the MacM practically every day, some great long weekends to nearby destinations and a two week sailing adventure into the western Cyclades in beautiful Greece, I have logged just under 100 hours on the new Suzuki 100 and can confidently say that this engine upgrade is the best thing that has ever happened to my MacM.

I am just so very sorry I didn’t go this way from day one.

All the best and happy power-sailing!

Octaman

[beene]

Glad you had a great season on your boat.

Here's to many more.

G

[mastreb]

Octaman, to keep the keel trunk splash from happening you might consider bolting a pair of lead angle-irons to the _bottom_ of the keel, just large enough to cover the entire keel trunk opening. I'd fill the bottom of the keel with resin for strength and then drill through that, attaching the angle irons with counter-sunk screws. This will give you some added weight below (about 40 lbs. by my quick math) and if done with some care will seal up the bottom of the anchor trunk to keep water out.

Just a thought.

[Octaman]

Beene/G,
Hey man, I just hope you had a great time too. I recall it was going to be June before you hit the water (?)

Hi Mastreb,
Thank you for your input. Your idea certainly would stop the upwash. I’m not sure that 40 lbs which is about 18 kg would make much noticeable difference to stability under sail though - other than a heavier keel requiring more effort to raise. So, I would consider adding a plate the shape of the trunk profile to the bottom of the keel just to seal off the opening,; but it would have to be super light.
I think adding weight to the keel is worth doing only if you do the complete mod, replacing the keel, creating a purchase for lifting etc. Then again my other concern would be, the stock keel is made to snap if it hits something and the hull is made to withstand such an impact. If you replace the keel and strengthen it in the process of making it heavy, what will fail first in the case of an impact, the keel or the hull?

Octaman

[mastreb]

Then again my other concern would be, the stock keel is made to snap if it hits something and the hull is made to withstand such an impact. If you replace the keel and strengthen it in the process of making it heavy, what will fail first in the case of an impact, the keel or the hull?

The light keel plate is definitely the way to go if you don't want to upgrade the purchase. I actually think people are better off using the stock keel for weighted DB mods for exactly the reason you point out above, and adding weight with resin and lead pellets. I've never heard of an added weight standard DB actually breaking off due to lateral forces under heavy heeling, but it will still certainly break off if it gets grounded. Strengthening the entire DB is not a good idea unless you did something like my idea below.

I've been thinking about a heavy dagger-board with an angle cut off the top forward 12" of the leading edge (6" or so across the top), which then has a counter-sunk rounded SS tang projecting upwards along the leading edge. The tang holds against normal forward forces no problem, but if the DB hits anything, it bends first, allowing the DB to pull out of the trunk and dangle from the DB line. The only thing that needs to be replaced in this strike scenario is the tang, and you can keep your heavy keel mod without losing safety. Furthermore, you can jury rig the DB just by unbending the dang with pliers to get home and then replace it.

[Octaman]

Hi mastreb,

I’m not sure I follow your description 100% but I do get the principle.
Maybe you could start a new thread on this topic and perhaps make us a drawing that will help visualize what seems like a very interesting idea.

In the meantime, I’m sticking to the stock dagger board; I find that it serves me quite well. Additionallly, I don’t want to add any weight to the boat; I carry all the necessary stuff when cruising and weight does add up, you know. This is not too obvious when sailing but you do feel it when under power and speeding. Even with my mighty Suzuki 100, I do feel the difference when I am heavily loaded.

Happy power-sailing,

Octaman