Transom HP limits

[colbysmith]

I wouldn't recommend normally cruising at 30mph either. I had the Merc 115 on my 22. It was plenty. My top speed was around 32mph. As others have said, anything over 28 is dicey. I'd say anything over about 25-26mph things can get real squirrely real quick if you hit a wind gust or whatever. Regarding the 4 blade prop. I ran a 13.25 x 13 aluminum 4 blade on mine and it worked great for getting right up to max WOT. My best cruise speeds (and this also depends a lot on the individual boat), was either 13 kts or 16 kts. (About 16mph - 21 mph.) Just my 2 cents. Colby

[tsturm]

[Knipet]

[hardee]

There are even things that you can't see that you could find with an OB leg, and it is going to hurt. The faster you are going, the harder it is going to hurt.

Wind on the water is going to be the least of your worries.

Harvey
SleepyC

[T.R. Bauer]

[T.R. Bauer]

And as far as the 30 mph cruise, mine goes 30, or even a little more with twin 45s with a light load. But, they are screaming at 100% throttle and you know how wear goes at 100% throttle. I will counter what the others have said, if the boat is trimmed properly, meaning the bow isn't really down much, I honestly can't really tell the difference between 20 and 30 except I get places more quickly. Bob says the top speed is about 36 with the 140 - never gone 36 and have no intentions on it, but a 30 mph cruise in PWS is pretty nice and I'd love to have it. I think you're onto something here. I'm pretty sure my 400 hp truck will go 150 mph, but I don't drive it that fast.....weird....

BTW, I think you're insurance company would have to provide valid and sound arguments for any claims stating that the 140 hp outboard contributed. In other words, just because it is there, does not necssarily mean anything. And, most claims are dings at the dock, trailer failures, or running into somebody in the marina - all slow speed things. Well depends on the trailer failure....lol....I also agree that some lawyer could have a hayday with it....I'd be willing to take that chance in Alaska. In another state, maybe not.

Quick question to anyone actually knowing: Is the 100 hp rating really just a suggestion, or is it legally binding by the USGS for a 22 foot boat? I'm reasonably sure it really it is just a recommendation on boats this size.

[Kars10]

I just did a re-motor on my CD22 from twin 40's to twin 60's. Honda. I had to find documentation and proof that the HP ratings over 20' are manufacture's suggestions and not law bound. Any boat under 20' has to have an HP rating and has Federal Regulations. My insurance company said I was good to go. I think it ends up being the choice of the Ins Comp at the end of the day. Mine seemed very helpful. State Farm out of Monroe, WA. I also found a formula that if correct and all things being perfect would say the boat can handle 188hp. Yikes! Horsepower for over 20’. (6.333x22x2)-90=188.7hp No Thank You!
I didn't do the re-motor for speed, I did it for power in sketchy situations. The 60's makes it feel like a truck in 4WD. I have more control and a huge peace of mind when I'm out in the Puget Sound PNW. The waves get angry near Everett. Hunkydory's thread was the motivation for me. Peer Pressure! I'll share my data once I get out on the water more.

[san juanderer]

Hopefully the Administration can memorialize this conversation thread, as this topic has come up numerous times. And some responses have been rather pesky when the repower choice has exceeded the sticker on the dash.

Can the Administration save this info somewhere so it is easily accessed ? And not lost in time.
thanks

[Fishcatcher907]

[Foggy]

Speed is subjective and relative. Speed changes you. It actually changes time.

If you've sailed, 8 knots is good. I sailed a 61' C&C going into Villamora, Portugal
w/a small trisail spinnaker at 16 knots w/white water astern aplenty. It was
exhilarating.

I've gone 5 - 30 mph in multiple powerboats w/various impressions. I drove a
friends drag boat to about 100 mph which scared me. My deep-v 28' Saber
would do about 80 mph. It was like driving a sport Ferrai or Maserati:
responsive, sensitive, feeling like almost unlimited ability. It was a fix.
Nothing like it. Maybe a motorcycle.

Figure it out. You're on this planet called Earth. We're traveling about 67,000 mph
around the sun. Isn't this a gas? Get into the ride.

Enjoy it while it lasts. Enjoy reality.

Aye.

[jkidd]

[thataway]

The Formula one race boat weight 860# including a 400+ hp Mercury outboard; They are 20' long and 7' beam, made mostly of carbon fiber and Kevlar--I have ridden in one at 138 mph. That doesn't mean that you can just put any HP engine on any size boat.

The C Dory is just not made for high horsepower in comparison to many other boats that size. If you start looking at boats with high hp, there is a lot more structure in the transom, and support, such as stringers, transom knees, built up keels and keelson's.

When you have seen what happens to a C Dory transom when even a 115ph motor hits an underwater obstruction--It would make you perhaps re-consider what hp you put on the boat. Will the boat float and run? sure. But the practical limit for controllable speed is somewhere in the 30's. The Tom Cat is an entirely different type of boat--and with a couple of Suzuki's in the 175 to 200 can reach over 50mph and be in good control.

When we were looking at the construction of our first C Dory 25, I found that the plywood core did not go all of the way from side to side in the transom. The splash well was mostly chopper gun--and was not as strong as it should have been. As part of the rebuild process, we put several more layers of 1708 glass and epoxy both across the transom, and up into the supporting structure of the splash well.

I have a Suzuki 140 on the 18' Caracal cat. That boat basically uses the inner side of each hull as a support structure for the outboard. The load is far better spread out in that boat than in a C Dory 22. The plywood core, also extends to the outer hull where it mates to the transom, and is taken up into the cockpit structure also. The C Dory 22, uses the plywood core and the splash well--The load is better transferred out to the sides of the hull than our 2003 C Dory 25 was.

I believe that the newer 25's have the load better distributed.

[colbysmith]

TSTURM:

[Foggy]

FYI
Check out a beefy transom plug by clicking W B Nod under my side post ID, then
"Core Sandwiches".
That 5 layer thick one on the right is, from top to bottom, vinyl ester fiberglass -
3/4" marine plywood - VE fiberglass - end grain balsa - VE fiberglass.
You won't find a C-Dory transom like this one and shouldn't expect to.

Aye.

[DayBreak]

Nick,

I read your original starting post. Interesting topic for a power choice on a 22 Cruiser. A C-Dory 22 Cruiser is a great boat. We have a C-Dory 23 Venture and it is powered with a Suzuki df140a outboard. I never motor for prolonged periods of time at full throttle and if I do it is no more than for 20 seconds. Our boat is rather heavy as used. We have a 19" 3 blade prop currently. The Suzuki 140 is a 2044 cc 4 cyl. motor. I feel that it compares to a Suzuki 115 HP motor but is lighter because of design changes. When I hit the 6K rpms mark and do so ever so rarely, it comes alive and I have hit 34 Knots (39 mph) at best sea conditions. This speed is too fast for any C-Dory (basically flat transom reasons). The boat handles well at this speed but it is way too fast for my comfort. Definately, don't go with a Suzuki 140 HP motor on your 22 Cruiser. It would be a mistake in my opinion. Is there a reason for you to have this amount of power on a 22 Crusier? Wish you the best in your research.