Twin Suzuki 60s on CD22

jingram · Posted: Wed Jul 18, 2012 1:31 am Post subject: Twin Suzuki 60s on CD22

I've been checking out various outboards recently as I look to purchase and I know that the hull speed on the CD22 is now rated at 115. Would a dealer be able to install twin 60s on that boat even though it would come in at 120 or are you forced to drop down to 50s? The DF60a, DF50a, and DF40a all come in a 229lbs, so the difference is going to boil down to hotter cams, bumped compression, and/or changes to the ECU. Since the weight is the same I would lean towards 60s, but wasn't sure if this was even doable with the hull rating being 5hp under.

thataway · Posted: Wed Jul 18, 2012 1:54 am Post subject:

Why twin 60's--you are correct that the difference is basically valve timing at the top end. Since the C Dory becomes a bit squirrelly at above 30 mph, there is no sense to power the boat faster than that speed. 100 HP should do that.

Hull speed has nothing to do with maximum HP. Max HP is determined by the builder taking into account many factors. You are correct that transom weight, force on the transom (torque of the engines) as well as hull design are part of the equation. Remember that these boats were designed for a 70 hp engine.

Hull speed is basically 1.34 x sq root water line or assuming a 19 foot LWL on a C Dory 22, the hull speed would be about 5.8 knots--the max speed a hull is easily driven before it begins to "climb over its bow wave"--a simplification, but partially defines when a boat begins to plane. The C Dory 22 will begin to plane at low speeds--we disagree amount our selves, but about 10 to11 knots is a generally accepted speed.

Would you damage the boat with two 60's?---probably not... it is more engine than you need? Probably.

jingram · Posted: Wed Jul 18, 2012 2:07 am Post subject:

Looking at things and the cost differential is minimal so it was sort of a why not type of question.

It seems like a number of folks are quite pleased with the 115 over the 90 and I would assume resale would be slightly better.

starcrafttom · Posted: Wed Jul 18, 2012 2:22 am Post subject:

No fancy math from me. Get the most hp for the weight. I like to run a bigger engine at less throttle then a smaller engine at more throttle. I always feel cheated when a 50 hp is the same engine as a 60hp just detuned. Why? just does not compute to me.

jingram · Posted: Wed Jul 18, 2012 2:28 am Post subject:

My thoughts exactly... the only reason I could see not to go with 60s would be if they were simply shifting the horsepower/torque curve up the rev band which wouldn't translate into any better performance or mileage depending on how you were running.

The question is can you even mount the twin 60s with a hull rating of 115?

Captains Cat · Posted: Wed Jul 18, 2012 7:03 am Post subject:

Heck, you "could" put 200hp on there. The problem would be with your insurance company or law enforcement should something go wrong. Why take that chance?

Charlie

Sea Wolf · Posted: Wed Jul 18, 2012 8:44 am Post subject:

Most marine dealers won't mount a larger engine, or engines, on a boat if it exceeds the manufacturer's ratings for the boat. It's a liability issue, and they don't want any part of a lawsuit.

If the 60 hp engines are simply the same as the 50's, but more highly tuned-up, so to speak, you won't see any performance difference in the rpm range you'll want to be running them at constantly, nor any difference in fuel mileage, either.

The only real differences would be

1.) if you had to come in on one engine and the 60 hp would plane the boat and the 50 wouldn't,

2.) the initial cost, and

3.) HP bragging rights if you're 25 years old or under (!) Laughing

I'd go with the 50's. Plenty of power, and simpler (KISS Principle).

Joe. Teeth

ghone · Posted: Wed Jul 18, 2012 1:11 pm Post subject:

I think twin 60's puts you into the "experimental" side of things. We have a lot of really well traveled boats with twin 40's or 50's. Twin 60's may be a first. If you can find a dealer to do it and insure it and money is no object it may be doable. But..... Certainly not recomended or needed. My single 90 in light load conditions on flat water will run just over 30 mph. She feels rock solid but too fast to be there long. I would bet the average 22 spends the majority of hours under 15 knots. I'd go tried and true for simplicity and safety. George Thumbs Up

jingram · Posted: Wed Jul 18, 2012 2:28 pm Post subject:

Thanks for the input guys... like I said, same weight, relatively same cost, so it was sort of a "why not" type of question.

I guess I will see what comes to pass... clearly this has been reevaluated by the factory through the years, hence the bump to 115.

I've read a number of threads after doing searches before I posted this where I found guys complaining about twin 40s even, so I figured why not purchase the extra power now at minimal cost increase, especially since the motors weigh the same.

Nainu · Posted: Wed Jul 18, 2012 2:52 pm Post subject:

I have never felt "overmotored" with twin 45s, but I don't like to run at WOT for fuel economy reasons and wear and tear on the motors at 6000+rpms. I cruise at about 25 knots, rather than the 30 I could get at WOT. So I would agree that you do not "need" twin 60s. Also, a boat is not the same thing as a small aircraft where having a little additional power may be the difference in getting you out of sticky situation. I have the bigger problem in that my boat is rated for 90 hp and I may have to repower with twin 40s.

But then again your question is why not have twin 60s. First issue is liability - if you have an accident in your boat, expect an opposing lawyer to make it an issue even if it had nothing to do with anything. A related issue is getting an insurance company to insure you (although I am not sure that an Allstate or Progressive or other company would catch it). A further related issue is if you might ever use the boat for commercial purposes - I guarantee a commercial insurance company would have a problem with it as they usually require a survey.
The second issue is resale value - a potential buyer could be put off by an overpowered boat, which could in turn mean that you will have to take less for it or wait longer to sell it should you choose to do so someday.

I don't think these are issues of great concern for most people. And I agree that the more power for the same weight is attractive, but I just don't know that you would ever notice the difference between 50s or 60s from the practical standpoint. So I see the issue as why should you go with the 60s, not why shoulgn't you. Personally I would stay with the 50s.

UncleRichie · Posted: Wed Jul 18, 2012 3:38 pm Post subject:

A little more life out of the 50s and more miles to the gallon? One would think a hundred horses would be enough I get by nicely on 75 Suzukis are good engines.
Richard

VESHAY · Posted: Wed Jul 18, 2012 6:55 pm Post subject: tower of power...

I passed on a 2007 C-dory with 115 HP motor b/c I felt powering to the max wasnt necessary. Instead I bought a 2000 C-dory with twin 40's b/c it had proven right combo for previous owner who put many hours and many hours on a boat so powered.

thataway · Posted: Wed Jul 18, 2012 9:44 pm Post subject:

Captains Cat · Posted: Wed Jul 18, 2012 10:11 pm Post subject: Re: tower of power...

jkidd · Posted: Wed Jul 18, 2012 10:11 pm Post subject:

When I bought my boat the 22 was rated at 100 hp. I talk to the factory about putting a Suzuki 115 instead of the 90 which at the time was the same motor for both horse powers. They told me that they were fine with it because they were more concerned about the weight. The reason for me was altitude. I seldom run at WOT. They just left off the capacity decal, the 22 doesn't have to have one. That took care of the insurance guy and the rangers. I did discuss it with my insurance company and they too said they were ok with that. I can't tell you if the additional 5hp will do anything to you or not. You might not ever use it.

PS: Six months after I got my boat the factory change the decal to 115hp.