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Best engine for a Mac 25?

Posted: Mon Aug 06, 2007 1:29 pm
by livingstone
Hey yall.

I posted on another forum this same question, and got varying replies. My question is whether an upgrade from my 8hp suzuki would be helpful (like to 15hp). The reason being, that the 8hp is great for reaching hullspeed in flat water, but I thought in really large waves, currents, or winds or chop that the extra hp. might add to control and maneuverability.

If not, why are they putting all of these big engines (I've heard up to 50hp, I think) on the 26s which have a pretty similar hullspeed?
Anybody have an opinion?

Thanks,
Jack

Posted: Mon Aug 06, 2007 8:16 pm
by James V
James Bladwin cruised the world in a Pearson 28 for years. I had emailed him this question and his reply was like some others. The more experience you have the smaller motor you need. the reverse is also true.

A bigger motor will get you out of the trouble that you get yourself into.

I was needing gas and I had go dock down wind in 15 to 20 knot winds. I came in to sharp and I had to back out. The wind pushed the boats stern towards another High $$$$ boat. With my motor I was able not to hit it. If I had had a 10 hp I could not have done that.

I was going through a bridge that had just opened. Again 15 to 25 mph winds. There was a traffic bridge and a train bridge with a bad wind sheer on the other side. A trawler went through before me and was going to slow and the wind hit the bow and pushed him into the pilings. Being to close behind I had to turn the boat and hit the motor hard to get out of the way.

Setting the anchor. A small motor will not cut it when you are expecting 30 mph winds and want to know if the anchor will hold.

A high thrust motor will help.

Posted: Tue Aug 07, 2007 3:30 am
by Catigale
Jack - someone here will correct this as required but I believe the Mac 25 (what year is it) has a traditional keelboat non-planing hull so adding extra horsepower is a waste of time

The :macx: and slower blue :macm: have powerboat flattened sterns which allow them to approach planing with a 50 HP or larger motor.

Posted: Tue Aug 07, 2007 3:33 am
by geocat
I totally agree with James V . I had a SELVA 15 on my :macm: and I had a lot of problems with strong winds and currents (specially under bridges). An other reason is that with a small engine you can not pull out the water ballast while at sea. Recently I have instoled a Yamaha 50FT and I feel more safe.

Posted: Tue Aug 07, 2007 3:39 am
by geocat
To Catigale: What do you mean with: slower blue :macm: ???

Posted: Tue Aug 07, 2007 3:43 am
by Catigale
Geocat - its a standing joke on this Board that the colour of the hull impacts the speed of the boat - sorry for confusing your post with a joke

Apologies...Cat

:)

Posted: Tue Aug 07, 2007 3:48 am
by Moe
Besides not having the powersailor hull with all that displacement aft to float a heavier motor, the Mac 25s don't have all that freeboard that causes the boat to be blown around. They are rated at 10HP max.

Posted: Tue Aug 07, 2007 3:51 am
by Catigale
Thanks for confirming Moe - Ill bump this to the Venture Forum after it plays out.

Posted: Tue Aug 07, 2007 3:58 am
by Moe
There's one in our marina that's out just about every weekend, and I can tell you it sails very well upwind! 8)

Keep in mind the 10HP motors the 25 was rated for weighed a lot less than todays 4-stroke versions.

As I said in the duplicate post, ...It doesn't matter how much horsepower you have if big/steep waves have the prop out of the water much of the time. If you don't have one, a 25" extra-long shaft helps with that some. Just make sure you can tilt it up far enough to get it out of the water when it's on the leeward side when sailing.

Posted: Tue Aug 07, 2007 4:01 am
by geocat
Thank you for replying fast Cat. I was beginning to scrap the paint

Posted: Tue Aug 07, 2007 6:27 am
by James V
Moe - I can agree with you on the wave conditions, but the extra horse power in making turns is really nice.

I can see a point on the extra weight of the motor but with a boat fully loaded for cruising, the difference in motor weight is not that much for the extra safety factor.

I think

Posted: Tue Aug 07, 2007 9:07 am
by livingstone
I guess comparing it to the 26s was irrelevant, so scratch that.

And please note, when answering this question that I realize the hull speed of my boat. The question really is:

When it's not going at hullspeed, but going full tilt with the 8hp, (ie: into a strong wind, under a bridge, up a large wave) would more hp do the trick.

And to weigh in on the equation of more experience means less motor needed, I'm on the less experience end of that spectrum.

Thanks for your consideration, folks. And sorry I posted it twice. I thought I sent the 2nd to Cruisersforum. My bad...

Re: I think

Posted: Tue Aug 07, 2007 5:25 pm
by Moe
livingstone wrote:I guess comparing it to the 26s...
If by 26s, you mean 26 plural, there are four 26 foot models. Two were sailboats like your 25, except they used water ballast instead of your weighted swing keel. One, the 26D, had a daggerboard, and the other, the 26S had a swing centerboard. Both are sometimes confusingly referred to as a 26C for classic (pre-powersailor). If I recall correctly, both also had a max HP rating of 10, but someone can correct me if I'm wrong.

The next two 26 models are water-ballasted powersailors, their hulls a compromise between sailboat and powerboat shapes. The 26X had a swing centerboard, and the current production 26M has a daggerboard. These models also have a lot of freeboard because they have standing headroom inside, at least in the aft part of the cabin. They're designed for 50HP and can carry that because of the large amount of hull in the water at the transom, providing bouyancy.