Finally got me a Dyne! Power options?

Wow! 900HP with triples? I bet that is a truly awesome boat.

I did not know that the Rock Jays sold the boat and was not told that by the rigger. I wonder why?

Stapletm - I could mount twin 200's for the same weight but I do not need that kind of power. My boat is a 72 with a redone transom 10 years ago. Not sure if I want to hang 400hp on that. What I want to be able to do is jam the throttles forward and be pinned back in the seat by G forces if I feel the urge. The 16' Dyne I played with in the mid 70's with twin 115's did that up to 40 or so and topped out at around 45. All I want is a twin Dyne with 4 strokers for family use and my pleasure to experience the truly religious experience of driving a twin Hydrodyne (a triple would blow me away!). And the fuel economy and quiet operation of 4 strokers.

I like leading edge technology and in the marine world Verados are it.

Some have said on this thread that I am set in my desire to hang the extra weight on the transom for the 4 strokes and that is a correct statement. I am very comfortable with too much power and weight on the back of a boat. My Venom is the prime example.

The rigger also told me that there is much more cost to rig a Verado boat than just the motors. That was interesting to hear and maybe I will go with twin 115 4 strokers like the one on my pontoon boat. The 115's weigh the same as the 150's but are far cheaper. Twin 115's would be ok and about 10K(?) cheaper than a pair of rigged 150 Verados.

A pair of Tower of Power Mercs would be really cool but I want more modern power with less noise and better fuel economy and not have to mix fuel and oil.

This boat will only be used for for family water ski use. I have a Venom for when the speed bug bites me but nothing can accelerate like a twin Dyne. That is really cool.

 

"The 115's weigh the same as the 150's but are far cheaper." You sure about this? The Merc site says the 115 is about 110 lbs lighter than the 150?

That aside, not sure a pair of 115 4 strokes would give you the punch out of the hole you seem to be after. Once you remove the Verado supercharger, 4 strokes go back to having the inherent problem of being a little slow to build power IMHO. I'd seriously consider 115 Opti's if you want to scale back. True, not a 4 stroke, but pretty close in terms of fuel economy (3 star CARB rating just like the 4 stroke), marginally lighter, but still the 2 stroke kick in the pants. That would be a pretty sweet twin set up, I'm surprised no one has done it, or have they?

 

Twin 115's on an 18 has been tried by one of the clubs a few years ago. It did not last long.

The bottom line for a club is that if you want big pulling power you need a 20.

The 18 is more fun to drive and works well for a family. A twin 18 only made sense for a club before the 20 came out or if the driver just has to have an 18. A single 18 is good where low wake or low speed is needed.

Big weight on the back of an 18 really screws up the low speed wake and increases the speed at which the boat comes on plane. My 18 has a 370 pound 150 and comes on plane at about 10 mph which makes it good for little kids and swivel skiing. It would also be a good barefoot boat.

I understand the desire for a twin. If you want a big hole shot you need some light weight 2 strokes.

A friend and I set out to design a light weight big power Merc a few years ago. It never happened because I am pretty happy with my motor. We figured that we could build a 2.5 liter 150-200 hp motor that would weight between 300-350 pounds by carefull selecting the lightest components from several different models. We actually weighed a bunch of components. It would probably be louder and use more fuel than the surrent lead sleds.

Have you driven the boat with the 175 and a 17 or 15 prop? It will have a hole shot that will feel like the seats are going to be ripped out, and will probably out accelerate the original twin 100 Dynes.

jim :wave:

 

You need to go for a ride in Dynebob's 18' with the big Merc on the back. That boat is scary. When he jams on it from a stand still it will literally throw you to the back of the boat if you are not holding on for dear life! I think twins are overkill for what you want to accomplish. A large horsepower Verado should work awesome.

 

I am not dead set on 4 strokes but am on twins. Merc makes a 150 XS Opti with a 3 star rating and a straight Opti with a 2 star rating. At the speeds I will be at most of the time I could live with the small amount of additional noise a pair of 2 strokers would make. The 70's Dyne I have had experience with was relatively quiet at ski speeds but that pair of 115 Johnsons drank alot of gas.

Can anyone tell me if the fuel consumption of a modern 2 stroke is much better than a 70's 2 stoker and how a modern 2 stroke would compare to a 4 stroke? I have an 07 225 XS (3 star rating) on my Venom which is not too thirsty and not too loud when cruising but that is comparing apples to oranges.

The 115 I referred to in an earlier post that weighs 510 is a Merc 4 stroke but not a Verado. I have that motor on my pontoon boat and the 1st time I started it it was so quiet that I thought it didnt catch and turned the key again. Oops! Now I look at the tach.

My old club has twin 150's on their Dyne but I am not sure what Opti version they are and I think it they are on an 18 footer.

 

TJ,

You're asking a question where there is no "correct" answer. I touched on this a while back as follows:

First thing, people have to realize is that one ski boat cannot be all things to all people. For example, if you want a brand new high-end inboard ski boat, these boats most likely won't satisfy those people with a smaller budget. Another obvious example is that you won't see many triple rigged 20'ers pulling skiers at three event tounaments.

For those people looking for an all purpose family ski boat, IMHO, nothing beats the value and versatility of a 17.6' or a 20' open bow Dyna-Ski. I've had numerous people either email me or call me and ask how I liked my 17.6 Dyna-Ski. In a nut shell, I compare my 17.6 to a motor vehicle as follows; the boat is a tractor, a sports car and a minivan all wrapped into one. Of course there will always be a tractor that can pull more, a sports car that can go faster and a minivan that will hold more people, but I think Dyna-Ski has balanced these requirements well. Remember, every boat will have limitations and cannot be all things to all people.

IMHO, there is a lot of bang for your buck in a base model open bow 17.6. I personally wouldn't power these boats with less than a 115hp motor and after that, prop selection is based more on what you plan on using your boat for.

The twin rigged 18' Dyne remains my favorite boat of all time. Of course, even this boat has it's own limitations and at my place, a twin rigged 18' Dyne wouldn't pass the "wifey test" for family use.

In short, I think what you want is the fun of driving an older 18' Hydrodyne with the joy of modern (yet heavier) motors, and that's fine. But other than that, there really isn't a practicle application to your proposed rigging. But hey, to each his own. Ask DyneBob, he's drivin' this boat with single small blocks, twin small blocks and a single big block.

Like Jim said, if you want to go beyond twin small blocks, your best bet for overall performance would be a 20' Dyne which is more suited for heavier motors.

Anyways, you asked, at that's my 2 cents worth. Regardless, the 18' hull provides the most fun factor of any Dyne ever built, IMHO.

Kevin

 

I have 3 boats. One is a detuned raceboat, the 2nd is a pontoon, and the 3rd is my Dyne. I realize one boat cannot do everything - that is why I have 3. I am a retired military test pilot and so do realize that one platform that flies cannot do everything. Do you want an aircraft that can transport 500 people? That aircraft probably could not shoot down a fly but an F18 which I have flown could shoot down anything.

Same with boats. I have a go fast boat, and a pontoon for partying and to keep the wife happy and now the Dyne. The wife will never get into my Venom and probably not the Dyne. I dont care as long as she is happy with the pontoon.

The Dyne is going to be for skiing only and also for my pleasure for driving a twin rig. I want the twin Dyne to be quiet and economical on fuel. If a pair of lighter 2 strokers can do it I will maybe go that route. I think even if I power this boat with a pair of 115 non Verado Merc 4 strokes it will give me the acceleration and hole shot I want and the weight of the motors would not be a factor in my application.

There is no correct answer but I am looking for information on 4 strokers vs 2 and on fuel economy.

 

Hopefully Bob will chime in here and give you his opinion. He owns a 18' with a single 250 (That is a monster!), a 18' that had old towers of power on it, and then he repowered it with two 150hp Merc two strokes. So he has experience with all sorts of powered 18's. From the sounds of your previous posts, the main thing you are looking for is neck breaking power out of the hole. Once again my opinion is that you will achieve that with a large single big block similar to Bob's set up.

Greg

 

There is plenty of anecdotal evidence on the web about verado vs opti fuel consumption with the advantage going to the opti in the midrange and the verado a little better on the top end. The stories vary a little with different writers.

This stuff needs to be taken with a grain of salt when applying it to the Hydrodyne 18. It only has a 6 ft beam and with soft chines it is more sensitive to added weight and the lower speeds than the more modern wide beam boats. The Verado added weight will cause even more fuel consumption on the 18 at the lower and midrange speeds.

If I were going to build a 300 hp firebreather (and I don't recommend it) I would go the route that Dynebob went and use the older and lighter 150's. They weight less than a modern 115 which is ridiculous. I would actually use custom built motors for less weight.

I would go for sheer performance with no regard for noise or fuel consumption, that is for pontoon boats. The result would be something similar to the boat in this thread:

http://www.hydrodyners.com/forum/viewtopic.php?f=23&t=111&start=0

The fun factor will go up proportionally to the noise and fuel consumption.

jim :yahoo:

edit: I would do considerable mods to the boat for added strength.

 

Did some research. There is a report out there by Powerboat Reports that did a comparison between 150 hp Verados, 150 Optis, and some other brands of 150's. They compared 6 150 hp motors - 4 4 stokers and 2 2stokers. I could not get the report as it was copyrighted. What I did get was that the 150 Verado was only in the middle of the pack for noise and the 150 Opti was the loudest. I could not get specific info about fuel economy but what I gleaned between the lines is that a 3 star rated 2 stroker was not too far behind the 4 strokes for drinking gas.

Ed's marine will sell a pair of 150 Pro XS 2 strokers for 20K which would weigh 750 dry..
Ed's marine will sell a pair of 115 4 strokes non-Verados for 15.5K which would weigh 1020 dry.

I am eatimating that it would cost 2K to rig either of these packages.

Jaco's Marine in TN will sell me a pair of Verado 150's for 21.5K which would also weigh 1020 dry.

After talking to the Rock Aqua boat rigger it would cost 5K to rig the Verados.

I do not have complete information on fuel consumption on a 3 star 2 cycle vs a 4 stroker and that would really help.

So here is where I am at:

A pair of 150 Pro XS motors for about 22K. A bit loud, light, great performance, maybe a bit thirsty.

A pair of Verado 150's for about 26.5K. Quiet, heavy, enough performance, better gas economy. (how much better?) And leading edge technology.

As I said in an earlier post I am not dead set on 4 strokers but am on twins. I want a boat that is fun to drive but will not kill me at the gas pump.

I also made a math error in an earlier post that said only an additional 160# for a pair of Verados over Optis...it's closer to 300 pounds.

So here are the facts and numbers - have at it.

TJ