27 Power question
 

OK gurus,
Here is the quiz for the day..:D

Would a new single 350HP outboard be enough muscle to push
the recent addition of the 27 CC?

Yes it will not be a speed demon, but that is not the intent
of this boat.

It will be used as a tender for a 70 Hatteras M/Y that will live
it's life in the outer islands of the Bahama's..

Bring it pro and con..

Thanks..
Attachment 5404

Attachment 5405

I assure you I have no direct answer. But a 300HP Bravo 3 I/O does well with the 25 seafari- ~27-28kt cruise. So I think you are in the ballpark if the center of mass isn't terrible.

edit: clues here: http://www.classicseacraft.com/broch...ure/index.html

http://www.classicseacraft.com/broch...ure/index.html

Max allowable HP 600, wweight 7000 lb, rated for dual 2.6 OMC sea drives (2 x 175hp-200hp) or a pair of real outboards.

Expected dry weight?

Hey Ken, I know of one guy who has a 350 Yami, he says it has one problem.....that V-8 eats gas like crazy. However if you can afford a 70'er you can afford gas for this one.

For sure the 557 outboard by 7 Marine, 557 HP electronically controlled aluminum small block V8!

Did I miss something?? When did you buy that?

Horse power might be adequate, but torque is likely to be an issue. Planing at low speed is where it will show up.

Hey Ken,

My buddy is in the same boat (Literally). Please let me know what you decide. He picked up a 1986 27' Center Console version that is listed at 5000.00 lbs dry. It currently has Twin 1999 Yami OX66 Fuel Injected Engines on a bracket that run fine with less than 400 hrs each. He is going to keep the Engines for the upcoming season, but was thinking of re-powering if he likes the boat. My thought was a single 300 Etec at about 540 lbs. My thinking was my 27 has 350 Diesel HP (At the flywheel, Lots of torque and Huge Props). I have plenty of power for what I do. I can cruise at 30 Knots if I push the Engine to 3100 RPM. I usually cruise at 2700-2900 at about 24-27 Knots and I top out about 35 knots loaded, was about 37 knots empty at 3500 RPM (My boat weighs around 8000lbs). There are few days up in the NE when we can cruise above 30 knots, yesterday was one of them. Anyway, I figure my Engines weighs about 1800 lbs, Engine, Jackshaft and DPH drive. He would have 300 HP (At the Prop) and less 1300.00 lbs of added weight. He is pushing 500 HP, the boat flies, close to 50 knots. Take away another 530 lbs (one 250 OX66) and the drag associated with it, and shave the HP from 500-300, it should have similar performance as my boat, maybe better. I was thinking close to 40 Knots with a cruise around 25-30 with decent fuel economy. I figure the 4-stroke would work too, but just a little heavier. I realize the Engine will work a little harder and will use some fuel, but it should be fine. Not a rocket ship, but decent. He will be taking up to Six Passengers, but just off Chatham and the rips below Monomoy, from Ryders cove and Maybe an occasional Tuna trip in close.

Bottom line, I think it will work. I hope you do yours first (LOL) Good Luck

Second this ^^^^^^

The 7 Marine 557 is a BEAST! Makes the Yami 350 seem like a boy.

Heck Big Money, why dont you just get 2!

;)

Yam 350 is ~ 800#so hp to weight ratio is not good IMHO.

The 7 Marine 557 isn't light either weighing in at 1045#, but you are getting 207 extra HP compared to the Yami 350.

Hard to beat the Rude E-Tec 300 h.p. for power to weigh ratio (528 lbs)

7 Marine 557 torque = 550 ft lb. 1.8 lb. per hp. price $68k. Yam 350 2.4 lb. hp.

Being that it will be out island, I would go for twins. The new engines are quite reliable, but with little support close by...I'm just saying.

One motah or 3. 300 hp is fine. You ask of balance. You know.
Cheers,
GFS

Ken, the Royal Bahamian Defense Force used to run a 27' SeaMaster with transom-mounted twin 220 hp Yamaha's. The boat was converted from twin 165 hp Mercruiser's. It was capable of about 38-40 knots, and could (just) plane on one engine with a propeller change.

That being said, I echo the idea of keeping with twins.

If the Hat is over at Treasure Cay on the east side of the Abacos, and you've taken the 27' "Tender" to fish the Berry Islands for the day, it would be completely suckish to have your one and only motor decide to quit halfway between Little Harbour and Laroda bay.

If you're going outside of US territorial waters, either sails and a motor, or two motors are a must. The second motor can be a worthy "kicker", but two motors are a must.

Maybe Denny or someone else has made the crossing to the Bahamas more than I, but they'd be hard pressed to do so.

I grew up within walking distance of Lake Worth Inlet. With my grandfather, I made my first crossing to Jack Tar @ West End at the age of 5 in 1965, and I planned, navigated, and drove a 45' Rybo across before my 10th birthday.

All in all, I estimate have made/been at the helm for somewhere around 150-200 crossings from the US to the Bahamas, in boats ranging from a 13' Whaler (15-20 crossings in company) a 19' Robalo (8-10 crossings) a 20' SeaCraft (50+ crossings), to a 1926 40' Matthews (2x) to a 45' Rybovich (40-50 crossings) to an 87' Lantana (once).

I offer the perspective of experience. Keep twin engines, or a single with a good kicker. As I've said here before, I once came all the way back from Memory Rock to Ft. Pierce on a 9.9hp Chrysler kicker motor on the back of a 25' Robalo. Not something I'd want to do again, but I got us home.

I would think that the yammie 350 would be heavy a bit but no more than a pair of v6 motors. It looks like the bracket is a dusky bracket just like the one I had and modified. If it is that is one heavy rascal. I would change the bracket to something a bit lighter and more updated. If it is a dusky it will have a part number on the bottom of the tub starting with a "D" towards the back of the vee. I was planning on installing a pair of 3.0 225 hp mercury's I had on the back of her if I would of got down there to the boat before it was sold. Like F Franks said, I would want twins down there and would not trust a single even if it was a brand new one. Far as hp, I think the 350hp would work but I would go 450+up to be able to plane out on one motor if there was a failure. 300 hp would push her just fine I would think due to I have just one of the 225hp motors on my 27' now and it will hit 43-45 mph on the wrong over propped wheel now. I know there is a big difference between my 27' and this one but it is surprising how well the seacraft hulls do on such little power. The big 27' might be an exception to this but it would probably do better than other vessels similar in size. I think a new pair of 225-250hp optis or etechs would be be best on a boat like this or a nice pair of yammie fours.

Ken, ya should have bought my brother's twin 225 yamahas before they sold. Would have been perfect. I'm in agreement with the twins, besides the holes for twins are already in the bracket and for obvious reasons, we like to keep power drills away from you. :)

Ken - When did you get a 70ft yacht?

I vote for twin 150's. BTW - Great looking 27.

The 350 Yamaha's are great motors and would be a solid choice for a tender. Even though the weight is a little on the high side you would be minus the extra drag of the second lower unit. Twins....ehhh double trouble and expense. Modern 4 stroke outboards are well beyond the reliability we have been used to in the past. If you want a trouble free, low maintainance motor that doesn't need expensive oil and gas, go with the 350.

I want thank all of you for responding to my post!

1st. The 27 CC is not mine, it belongs to a friend of little Kenny!
He is working on it here at Area 442, why? because it's here.
2nd I do not own a Hatteras M/Y. I have a close friend that does and
he is also looking at another 27 that will be going to the Bahama's.
3rd. Having two 27's side by side is kind of unique!! Not something you
see in the wild every day..:cool:
There is no doubt they came out of the same mold! :D
If and when the 3rd one shows up, it will be history in the making..

Hope this clears the air... :)

Thanks again guys!!

PS: Don, Kenny's buddy tried to do the eBay thing with your brother!
It was a dead give away by his eBay name! :eek:

How stupid am I?
Cheers,
Us.

Kershaw is sick.

Nobones that 350 yammy will be stolen quickly in the Bahamas. Food for thought.

Ken,

Too bad it didn't work out, they are in Stuart coming off his boat on their way to AZ.

Seeya

27 CC outa Ryders
 

We'll need to keep our fingers crosses that we get out of Ryders at anything below mid next year!!!!!!!

27 with a single
 

I can shed some light and perspective.
My Flybridge had a bravo 454 310 hp.
I did some reading on a similar boat weight with a single etec 300.
On my 27 i believe the single etec would be an advantage- set back on a bracket;
Running in cleaner water 10-15% advantage(what ive heard over the years)
Weight difference- 800#s lighter tha 454 with I/O
Advantage of two stroke vs 4 stroke two stroke delivers power on every piston stroke.

My concern is load on the lower unit gears.

No problema pal, I'll respond to anybody... Jimminy Kenji-san,freakin ladder slip mellowed yer a$$. Seems just a couple of years ago you'd a been standin' in front of that fish killing thing with a BAR, tellin yer kids former friend to get off yer propaty:eek:. Missed you guys at Anclote. Catch you at cayo costa or whatever. Be a little more insistent on opening pubs on Hump Night... Cheers.

Ken-After seeing that 27 hull of Kenny's friends in person here in Bradenton, It is very efficient looking and with Fr Frank's comments about the Bahamian Defense 27, it sounds like the 350 would work, twins sound better though. Very cool boat.