What determines Engine size

S

Stanley-J

New member
I see small bass boats with 250 hp engs or even larger. And some 28 footers with 3 250hps right out of their factorys.
What determines what size engines are allowed on our Cd's. I know the CD-25 started with a smaller size engines than they are allowed today, but why not a 250 or twin 250s? I'm somewhat happy with my twin 75's, but you never know what lies down the road when eng replacement may be required.
 
Chuck, lots of engineering goes into that. Transom strength is very important. It's a safety issue beyond that, the insurance company would take a dim view of you putting engines on it beyond what it is "rated" for. The USCG may be involved too. I think Jeff Messmer or one of the other boatbuilders on the site can give you a more satisfactory answer.

How fast do you need to go? :roll:

It's like us hams, why use a KW when 100 watts will do the job.... :lol:

Charlie
K4KBA
 
Captains Choice":2bv2dgnw said:
It's like us hams, why use a KW when 100 watts will do the job.... :lol:

Charlie
K4KBA
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Because we love to see the lights dim when we key those 4-1000A's.

Don
WA6WKL WA3LKH KJ0P WA6WKL, full circle
 
The US Coast Guard doesn't care what size engine you have, despite the plate on your boat -- which is only required for boats under 20 feet anyway.

Since this plate isn't required for a C-Dory 22 you can put any size outboard you want on them. Not saying this is smart, but there's no legal reqirements for the data plate nor maximum power for private vessels.
Boats under 20 feet need this plate in both the US and Canada.

The boat building associations and both Coast Guards publish recommended maximum engine sizes but they have no force of law.

-- Chuck
 
Thanks Charlie for the info.
Actually I can do about 31mph with the Honda twin 75's and a fully loaded boat. Fuel consumption isn't bad at cruise speed but....damn .....those bass boats go past me like I'm still tied to the dock.
Is the CD's transoms that much weaker or is it because they were just not built for it. My twins weigh in at about 900lbs and I bet a 250hp merc is less weight
Don, I do have a little helper with my base station around 1500kw but I normally run 150 watts right from the rig....but it's nice to know you have a little extra..hp.. when you throw the switch.
 
Thanks Chuck S for the info. There you go Chuck, you can put two 250s on there if you want and keep up with the bass boats. Or, you can let them follow you out into a 3-5 foot chop and see how fast they can go then. :shock:

I've got a Henry 3K that will run a whole lot more than the legal limit and I never light it off. But I always run both Honda 45s on my CD 22!! :lol:

Charlie
 
Thanks Chuck S. for the good info. I will keep my 75's and be satisfied with good fuel economy and the ability to keep going in some 6' sea's ...I did experience that last month in Florida.
Charlie, you should burn out the dust on that 3kw amp at least once a season...maybe we can mark our calendars and have an on air dust burner chat.
Regards all
 
Sneaks":fxfviv3y said:
Captains Choice":fxfviv3y said:
It's like us hams, why use a KW when 100 watts will do the job.... :lol:

Charlie
K4KBA
Click to expand...

Because we love to see the lights dim when we key those 4-1000A's.

Don
WA6WKL WA3LKH KJ0P WA6WKL, full circle
Click to expand...

Don- Are you still talking with all your buddies at sea on submarines on VLF, ELF, and ULF or what ever bandwidth they're on these days? Maybe a remote/virtual poker game set up or something???
 
Sea Wolf":2vw2l0vg said:
Don- Are you still talking with all your buddies at sea on submarines on VLF, ELF, and ULF or what ever bandwidth they're on these days? Maybe a remote/virtual poker game set up or something???
Click to expand...

Naw, they still can't communicate two way at those freqs anyway, Joe, just receive. Besides, the state wouldn't let me put up a dipole for 76 hz even if I could afford it.

SET THREAD HIJACK OFF

Don
 
What really controls maximum horsepower is the hull form. C-Dorys use a hull form that performs best at slower speeds, plaining at 10-12 and maxes out at 30-35. If you push the hull form faster, loss of control, chine walking, and broach and flip are the next real possibilities.

The factory powers the boats at a safe level considering their liability insurance. Unless you are experienced with high speed boating, BE CAREFUL OF HIGH POWER, HIGH SPEED BOATS!! Spend time at each speed before you move up to the next level.

Most pleasure boating is done at 45 mph and under. 45 to 65 mph is the next level and anything above 65 is high performance.

You can make a mistake in our C-dorys at 20mph and live thru it, but make the same mistake at 65mph and you can get hurt real fast!!

To me C-Dorying is about travel and exploration in comfort and style, not speed competition.

Larry H

P.S. Exceeding the factory's max HP recommendation will void the hull warranty and may upset your insurance company. It may also become an issue with the law if you were to be involved in a accident.
 
"What determines what size engines are allowed "

Money and balls.

so far in my life

Grandmas 69 GTO= 120mph
moms 71 mach 1=130mph
buddies fzr600=158mph
girlfriends dads boat=75mph
my feet 3miles= 17.50 min when I was young.

Sign on the bike shop in mad max. " speed is just a matter of money, how fast can you afford to go?"

boat and motor for the brave and menitaly challanged

347_Ida_Rae_20.thumb.jpg

369_allison.thumb.jpg
 
Gentlemen - my first 22' cruiser in 1996 was powered with a Honda 90. Mark recommended a Honda 75. The stat sheets says they weigh the same. I did extensive boating for nine years with that rig. Sea level up to 8,000 feet. Boating Yellowstone Lake was a real eye opener. With a crew of five, the Far West II couldn't climb out of the hole until a couple of fellows got in the forward berth. Seems an immutable law of physics takes over - about a 3% loss of power per thousand foot of elevation. The next year I put on Bennett tabs. That helped. Since moving to Montana, I purchased another 22'cruiser, now called the Far West III. It had a Merc 100 2 stroke, but I repowered with a Merc. 115 HP EFI 4 stroke.
Reasons? The original engine was good, but I wanted economy and less pollution. The hull was out of warranty. The insurance company doesn't care. The weight is reasonable - actually less than two Honda 40s. Besides most of my boating will be at 5,000 feet or higher. Horse power is measured at the prop, so the 115 will probably never put out 100 HP.
We all have cars that go faster than we will drive them. Mine will do 135 mph, but I drive 70-75. At sea level 115 HP is unnecessarily powerful, but I suspect on smooth water I will cruise at 4000-4200 rpm if I get back to the ocean. Somewhere in all this the skipper's judgment has to come into play, regardless of the ponies under harness.

Yellowstone
 
Yellowstone":1fua94m8 said:
At sea level 115 HP is unnecessarily powerful, but I suspect on smooth water I will cruise at 4000-4200 rpm if I get back to the ocean.

Yellowstone
Click to expand...

Well the factory has upgraded the maximum HP to a 115 fairly recently, thats what I ordered, for my CD which I pick up tomorrow. Red fox I believe has a 115 and uses it at sea level. I think the boat will handle great with that size power on the back, it won't be lugging as much when you want to hit 30 mph on those flat days, as far as worrying about chine walking or broaching, I would definitly say be careful, but I don't think the factory would have upgraded the rating if it was unsafe, besides that look at all the flat bottom jet boats going really fast, they seem to handle the speed ok in the right conditions. Obviously your not going to be running full speed in anything but near perfect conditions. I have a feeling the CD 22 will handle great with the 115. But as there a very few running that much power yet, we will see as more people start. I wonder what kind of speed I will be able to expect out of that extra 25 hp. I was thinking probably the boat will get up to 35-36 mph on average in good conditions running wide open. I know when I drove Tom's boat the Susan E in flat water I felt that it would be able to handle some more speed without sacrificing safety. It was a pleasure at 29-30 mph. I will post about the performance after I get the new boat, and have broken in the main.

Sark
 
I have an older 81 classic CD-22 with a 115hp suzuki for power. Just as a previous poster said it can take the boat faster than I run it. Under normal Alaskan sea conditions I rarely travel above 20 knots. But the motor doesn't have to work as hard to reach that speed. I have on a calm lake ran it up to 5500rpm, with the older classic haul, did 31knots on the gps and I didn't like the handling. I think with trim tabs it might have made a huge difference. On a calm day I run around 24-27knots, depending on load, at 4500rmp. Usually cruise at 4200 18-21knots.
Shaun
 
The older CD hull was a little flatter? Is that Correct? When you say you did not like the handling at that speed, what were you experiencing? I'm picking up my CD22 today, and it too has a suzuki 115 with trim tabs. I will be breaking it in all weekend so will probably be able to open it up for a short period at some point. Can't wait to see how it handles. :smilep

Sark
 
May as well add some more to the subject. When the 130 Honda first came out, I wandered by a marina (unnamed) one day, and lo, in the their marina sat a new 22 cruiser with that very engine bolted on the stern. The bow of the boat seemed a wee bit raised. No wonder, for that monster weighed almost 500 pounds. I was invited to go on a short spin with that rig , and I accepted. It didn't take very long to feel somewhat uncomfortable about the way the boat felt. Now the good folks at this marina weren't advocating selling the cruiser with the 130. They just wanted to check it out. Way too much engine! But now the factory has increased the tankage from 36 gallons to 50 gallons - another potential
84 pounds. And many people want a kicker - another 75 lbs. And an additional battery, etc., etc. Suddenly, the weight could increase beyond 500 lbs. I have decided not to have a kicker and carry only as much gas as I really need to avoid that 130 Honda squat. Will be interested in getting Les's informed opinion.

Yellowstone
 
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