Sportboat max hp

loose rivet

Petty Officer 2nd Class
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Jul 31, 2011
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151
I'm looking at a Duratech Sportboat, the title reads 1964.
It's got an manual start40hp Evinrude on it now that I most likely won't bother in favor of something more modern.
The tag on the splashwell reads 80hp for the max rating.
I have a perfect running 110hp Evinrude here, how out of line would that be on this boat?
My thought is that a 1964 80hp Evinrude would most likely have weighed in about the same, so I doubt it's weight will be an issue.
I can't see dumping a good 110 to go find an 85hp which would most likely be a compromise in weight vs. hp over a smaller three cylinder.
 

JoeMan

Petty Officer 1st Class
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Jun 29, 2006
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322
Re: Sportboat max hp

Let me say this. I've got the Neptune, which is the slightly smaller brother to yours, and it's a '64. The max on my tag is 60 hp, for a 15' 9" boat. Alone in the boat, I can get her to maybe 38 mph with the modern 60 hp. I believe my boat could handle an 80 personally, I'd probably get her up to 50 which is what I'd like. These boats are built like tanks. If I were you, I'd first make very sure the wood was solid, and I'd try the 110 first before you go and sell it in lieu of lesser hp. How much does your 110 weigh?
 

loose rivet

Petty Officer 2nd Class
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Jul 31, 2011
Messages
151
Re: Sportboat max hp

Let me say this. I've got the Neptune, which is the slightly smaller brother to yours, and it's a '64. The max on my tag is 60 hp, for a 15' 9" boat. Alone in the boat, I can get her to maybe 38 mph with the modern 60 hp. I believe my boat could handle an 80 personally, I'd probably get her up to 50 which is what I'd like. These boats are built like tanks. If I were you, I'd first make very sure the wood was solid, and I'd try the 110 first before you go and sell it in lieu of lesser hp. How much does your 110 weigh?

The 110 weighs 292lbs hanging on a hook, minus the weight of the hood. A buddy at work has an older 85hp that weighs the same.
The wood in the transom would be replaced no matter what, it's just a narrow strip of wood about 18' wide. The deck is also soft in the rear, so I'm sure at least the rear deck will need to be replaced.
At this point I don't have any numbers off it, but its a smooth hull, red and white in color, and has what I believe is a 1965 Evinrude 40hp on it.

My main concern would be freeboard at rest, no doubt the hull can handle the power. I don't want a boat that sits with the splashwell drains underwater at rest or takes on water if two people walk to the stern.

The way I look at it, even if I were to go with a 70 or 75hp OMC motor, I'd be at about 240lbs or so with power tilt and trim.
The current 40hp only weighs about 140 lbs or so at best.
I've not seen it in the water so I can't say what it has for freeboard. If I were to run a big twin with tilt and trim I'd be pushing 190lbs or so.

The bottom line is that I could easily sell the V4, but don't want to hang a 50hp or even a 70hp and find out it needs more, or that the V4, was the right answer all along.

Does anyone have any pics of a Sportboat in the water with a larger motor?
My thoughts are that if it was built for an 80hp, an 80hp back in the early 60's was most likely a 4 or 6 cylinder motor. An 85hp back in the day would weigh in the 240-250 lb range in a Mercury tower of power, and a fat 50 or larger V4 would be in the 225lb range.
In a nutshell, a modern V4 with power tilt/trim is about 80lbs heavier than the older 85hp would have been. To stay within the original 'rated' weight I guess I'd have to stay with a three cylinder if it's got power tilt/trim.
Already having the 110 though is what has me thinking.
 

JoeMan

Petty Officer 1st Class
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Messages
322
Re: Sportboat max hp

Can you run the battery and gas up front? If so...that more than balances out the difference between a 240 lb vs. 290 lb motor. Just a thought. What about piling some barbells or a couple bags of concrete close to the stern, adding to the weight of the motor hanging on there now so that you can see how she sits? I don't think you're going to have so much of an issue. That's a good sized boat. I believe my Merc goes about 225 lbs, I've got not 1, but 2 deep cell batteries on one side right back in front of the stern, and the 6 gallon tank is in the other corner in front of the stern...and with 2 people standing at the back, no problem. And mine is over a foot shorter, and the hull is lighter.
 

loose rivet

Petty Officer 2nd Class
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Messages
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Re: Sportboat max hp

I was thinking the other way, if I add weight with a bigger motor I'd take some weight out somehow. Maybe an aluminum deck vs. plywood? I'm sure I can knock off 50lb somewhere.

My only concern would be transom flex or fatigue over time, but the transom looks super well built.


I called the seller, he said the tag on the splashwell is from PA, the hull ID number is an assigned number, so chances are there's no way to get an exact date on it.
It's a smooth hull, has vinyl coated aluminum on top, the deck is white vinyl covered plywood 3/4" thick.
Are there any identifying features from one year to another?
 

JoeMan

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Re: Sportboat max hp

He is referring to the tag assigned with hull ID...I'll bet he's simply not come across the small Duratech ID tag. It's about 2 x 3 inches. As for the year...the literature for the '64 shows a light blue topped midship helm on the right side, whereas the '65 looks to be woodgrain topped. Hard to see if there are any other differences. Also the '65 is a photo, where the '64 is artwork, so who knows...could just have been drawn as light blue. If you locate the serial, that'll tell all.

Your boat is positively either a '64 or '65. This model was introduced in '64, and '66 was the first full year of Duratech production under the acquisition by Penn Yan...and Penn Yan built Duratechs had lapstrake hull.

I actually put in a 3/4 inch wood floor, and I believe it definitely helps this issue. Think about this - the weight added by a heavier wood floor adds weight which is distributed throughout the boat...most of which is not near the motor but is out ahead of the motor and up front, and thus I'd argue is not adding to that problem. By comparison, put the same motor on 2 hulls of the same length...one an aluminum boat, the other a fiberglass. The aluminum will sit a bit deeper in the rear due to the fact that there is less weight overall, the front end of the boat sits higher out of the water. The heavier floor also adds to the smoothness of the ride I get...again, because these are very light boats. Again, I'd strongly recommend you keep your battery up front if it fits well.

I added angle iron to my transom as well, fastening it on either side of the upper wood and running down on an angle to those beefy aluminum box stringers these boats have. After doing that, I then engineered cuts in the wood flooring so that I could attach the angle iron through it. I don't believe it needed it, but I wanted the extra beef.
 

loose rivet

Petty Officer 2nd Class
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Messages
151
Re: Sportboat max hp

The numbers on that boat are on a PA Fish and Game Comm. tag, it's a 6 digit number with the prefix PA.

The boat is called a 1984 on the title which calls it a 'Homemade Vessel' 'mfg Duratech'
The boat apparently got named a 1984 since that was when it was inspected in PA for a title or lost title.

I still haven't pulled the trigger on it, I don't think its going anywhere the way it sits now, and he's no advertising it.
He wants $1500 for the hull alone, no motor no interior.
The boat is painted red on top, white down the sides with blue bottom paint. The deck inside is 3/4" plywood over 2x2" wood cross members atop 5 large boxed aluminum stringers.
I can see where it was sort of an aqua blue before under the bow deck. The transom wood is in good shape except for the bottom 3 " or so beyond the top of the stringers. It's V cut to clear the middle stringer with aluminum angle and bolts securing it to the transom.

The boat is heavy, I measured the total length with a tape measure from the top rear edge of the transom to the tip of the bow I get 17' 2" long, the beam width at the widest point measures about 6' give or take an inch.

Someone else also thought that it needed more weight, the forward storage compartment has 6 huge lead railroad weights in it, probably about 300lbs or so. They're mounted to plywood panels made to straddle the stringers.

The battery is now at the rear under the splashwell. I'd consider putting the tank in the storage box, losing the weights, and depending on voltage drop issues, maybe put the battery all the way up in the bow, there's enough room under the bow to hold at least one battery, maybe two if I raise the floor a few inches and make hold downs.

As it sits now there's no rear deck, no console, and no motor, the forward deck looks to be intact. The hull looks great, not even a dent or ding anywhere.

If I knew what to do for a console, I'd probably go get it tomorrow. I'm a big man, so a side console may make the boat unbalanced when I run it alone, but I don't feel its narrow enough to put a center console in it, nor would I want to deal with cables run under the floor.
Also, there appears to be no flotation in the boat other than a few chunks of polystyrene under the front deck.
I'd consider either soda bottles or maybe insulation foam?

I have the 110 hp motor, controls, and plenty of other spare parts to put a boat together, all I need is a vision or plan for how this should look when it's done.
Something else that I saw and liked was stick steering, which would mean a row of seats down the middle, leaving the gunwales open to fish from. The only concern there is that the forward drivers seat would interfere with the in floor storage area, making mounting a seat pedestal a problem.
 

JoeMan

Petty Officer 1st Class
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Jun 29, 2006
Messages
322
Re: Sportboat max hp

Pool noodles under the wood floor for floatation. I know a guy which sunk a couple tied to cinder blocks...after a number of days, had not absorbed any water.

I know of another guy who was planning to construct his console in the center of his Duratech, because of the same reason - he's a big guy. That thread is here somewhere in the Duratech section.

Does the $1,500 include a nice trailer?
 

loose rivet

Petty Officer 2nd Class
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Jul 31, 2011
Messages
151
Re: Sportboat max hp

No trailer, but I have a super clean late model Load Rite here that will work. The trailer it's on is junk, an old TeeNee with rust everywhere.

I like the idea of pool noodles but can I get enough in there to do the job being that they are round and often hollow in the middle. Not to mention the cost. I was in Walmart over the summer and they wanted $5 each for a 4 or 5' noodle. I'd need 100 of them. I can buy foam insulation, the pink or blue stuff for cheap if I buy damaged sheets. I'd really like to find that pool noodle type foam in 4" thick sheets. I know they make it because I've seen it used as packing. There used to be a packing center here that used it, a relative worked there in the 80's and had a huge sheet of it he used in his pool like a raft.
four big guys could stand on a 4x8 sheet and it would still float.

I definitely don't want that white polystyrene. the few pieces I pulled out when I looked at the boat weighed over 20lbs and were soaking wet. They came out of the forward deck area near where the lead weights were.
The lead railroad weights also will make a lot of sinkers if I buy the thing, lead is getting hard to find in quantity lately.
I can't imagine wanting to add that kind of weight to any boat. Especially one with a 40hp motor on it.

How fast would one of these have been with an old 40hp on it? I can't imagine it doing much on such a heavy boat?
I even wonder if it would even plane out?

As far as layout of the boat, I lean towards the stick Steer idea but my concern is that the boat it so wide, i won't be able to reach a side mounted steering lever on one side and a throttle on the other. The boat is more than an arms reach to either side sitting up front, and even so, the removable floor panel would be right where I'd want to mount the seat post.
I also thought about mounting a normal helm up front at the bow in the forward down panel which would let me put a seat just ahead of that compartment but I think that puts my weight too far forward and my control cables would be really long.

I also thought about maybe the option of extending the raised deck area farther rearward and mounting a set atop the additional raised area but I thought that may create a safety issue where it may be easy to fall in the boat or trip.
 

JoeMan

Petty Officer 1st Class
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Jun 29, 2006
Messages
322
Re: Sportboat max hp

I wonder if the guy used weight to make the front end drop since that motor likely could not plane it out. Speed? I bet it would get up to maybe 18 or 20 with a good 40? Just fast enough to get you out to do some fishing or whatever. Certainly not a fun ride...in my book anyhow. I'm no speed demon or thrill seeker...but I'd enjoy it if my Duratech could hit 50. She'll get in the upper 30's with me alone. Planes in about 3 or 4 seconds. :)

As for stick steer with a center mounted seat, that's a good idea...and here is an idea so that you can easily reach. Click this image:

http://t0.gstatic.com/images?q=tbn:ANd9GcRMnJRG4nYjudmFS_7_MvApBdzVH9AirRZ4PAfkv7zNzwujndHdcA
 

loose rivet

Petty Officer 2nd Class
Joined
Jul 31, 2011
Messages
151
Re: Sportboat max hp

I wonder if the guy used weight to make the front end drop since that motor likely could not plane it out. Speed? I bet it would get up to maybe 18 or 20 with a good 40? Just fast enough to get you out to do some fishing or whatever. Certainly not a fun ride...in my book anyhow. I'm no speed demon or thrill seeker...but I'd enjoy it if my Duratech could hit 50. She'll get in the upper 30's with me alone. Planes in about 3 or 4 seconds. :)

As for stick steer with a center mounted seat, that's a good idea...and here is an idea so that you can easily reach. Click this image:

http://t0.gstatic.com/images?q=tbn:ANd9GcRMnJRG4nYjudmFS_7_MvApBdzVH9AirRZ4PAfkv7zNzwujndHdcA

I thought about something like the bracket in the pic but the Sportboat's sides are already vertical, anything I add would stick out and get in the way of fighting fish.

I made the guy an offer, it's a good deal lower than he's asking so I'll see what happens for now. It's not advertised for sale so I'm not in any danger of losing it to another buyer anytime soon. The less I pay the more I have to spend on it I guess.

I do want to at least be able to get on plane with any boat I buy, so most likely the old 40hp gets swapped out for something larger. I just don't want a boat that's so overpowered or hard on gas that it don't get used as often as I would like.

My biggest concern is the weight of the V4 and if it would do any damage to the transom.

I really like stick steer, it puts me right up front and lets me balance the boat with my own weight as well. It would also offset the weight of a larger motor. It appears that my weight or the best driving position will be with the seat at the rear edge of the forward deck, this opens an another issue of the drivers seat not being able to be a fishing position with a swivel seat since facing rearward would have the drivers feet dangling off the edge of the upper platform.

A solution that has crossed my mind is to split the forward compartment in two halves, and make the center area a fixed part of the deck with the seat attached, but that would severely lessen the amount of storage I have there if its used for anything other than a fuel tank.
If I get this boat, and decide to run the 110hp, I will most likely make the forward compartment a fuel tank area, if I run a smaller motor, I'll leave it as a storage bin. I'm leaning toward a slightly smaller motor for both the reasons I stated above and for pure simplicity of the fuel system.
 
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