27 vs 24 HP for 1988 Freedom 36/38

Anything that doesn't fit into the other Physical Systems categories
Post Reply
User avatar
gamayun
Posts: 228
Joined: Thu Dec 06, 2012 9:14 pm

27 vs 24 HP for 1988 Freedom 36/38

Post by gamayun »

OK, last question before I buy this boat (or not). The boat was represented in its listing as a 27 HP Yanmar, but it is actually a 24 HP. Would it be seriously under-powered? Why do all the other similar Freedoms for sale right now show 27 or 28 HP for 87 and 88 models. Was this more typical for good reason?
Kynntana, Freedom 38

User avatar
sailmon
Posts: 235
Joined: Sun Feb 22, 2009 6:53 pm

Re: 27 vs 24 HP for 1988 Freedom 36/38

Post by sailmon »

Yanmar might be able to tell you more about specific performance differences between the 24 and 27 (3GM30F) engine that we have on our 1991 F38. In my experience, the 27HP pushes the boat along just fine in flat water or following seas. I find the boat to be under-powered when motoring into a strong breeze and/or headseas. If I were re-powering our boat (hopefully will never have to) I would be going up one engine size.
Sailmon (Captain Bob Allenick)
S/V Her Diamond
1991 Freedom 38
Cleveland, OH

User avatar
gamayun
Posts: 228
Joined: Thu Dec 06, 2012 9:14 pm

Re: 27 vs 24 HP for 1988 Freedom 36/38

Post by gamayun »

It's good to know about your experience. Thank you. The following is the answer I got back from the Yanmar Corporation. I sent the email early last night, and there was a response at 6:17 am Pacific time. THAT was great....

All Yanmar engines come with two ratings. One is a continuous output rating and a maximum duty. The continuous duty means that you are operating the engine all the time at this rated rpm (heavy load). Ninety-nine percent of the owners of there vessels operate there engine at 10-20% of maximum wide open throttle, which in your case, your engine max RPM under way, under load is 3,600. So to safely use your engines, it would be recommended to operate your engine at approx. 2,900 - 3,200 rpms with the occasional run up to the max RPM of 3,600 for 5 - 10 mins every hour.
Your engine is a 27 hp @ 3,600 rpm engine.
Kynntana, Freedom 38

User avatar
hxschiller
Posts: 88
Joined: Sun Dec 07, 2008 7:55 pm
Location: Mull 28 - "Impulse" on NW Creek in New Bern, NC

Re: 27 vs 24 HP for 1988 Freedom 36/38

Post by hxschiller »

Another, important aspect of going upwind and into chop is to have enough propellor blade area. With my Freedom (Mull) 28, the factory-supplied 2-blade prop was borderline in going windward during tough times. I found a used feathering prop (PYI) whose blades had substantially larger area than the stock prop. When I put the boat on the hard to paint its bottom (the only reason to pull a boat in coastal NC), I switched props and I discovered to my pleasure that the increase in blade area transformed the performance under power. Even better under power performance probably is available by switching to a 3-blade prop, but unless it's a feathering prop, it will hurt sailing performance noticeably. The net: heavy boats need to push a larger quantity of water

Post Reply