197? 240 Sea Hunter Build

[Tx49]

X2 on what SeaBob said, I have close to that setup, 280 HP with the Bravo3, on my 25' WC    http://www.classicaquasport.com/gallery ... hp?cat=661

She flys with about 5000 lbs of displacement.....great fuel rate too, around 6gal per hour at 3000 rpm cruise.

Appreciate it. I think I might be another 500 pounds or so, but that seems close to what I am looking for. I want to be able to get into the mid 30's+ and cruise at around 25 -30 if I want to.

[pzart]

I run WOT between 44mph and 49mph depending on conditions and load, cruise is around 28-32mph....I love this setup....mine is 1997 throttle body injected 5.7, newer one's are mutiport injected and have 300+ HP. I can take off and outrun most 18-20 ft runabouts....but mostly I just putt around and get good fuel mileage.

[seabob4]

Tx, the stringers are no big deal, just have to space them properly and incorporate engine beds for the front mounts.  Decide mid-stream to swap over to bracket mounted O/Bs?  No prob.  The point of no return is when you cut the big ole hole for the transom assy...

[gran398]

Bob, what was the difference in the transom layup schedule, inboard vs. outboard? Should be some money saved on the thinner inboard transom, right?

[seabob4]

Scott, don't confuse I/O with I/B.  Inboards, hell, you just need enough material to keep it stiff (well, a bit more, but you get my drift ).  I/Os?  The transom is just as stout as an O/B transom.  Remember, you've got that drive hanging back there, the transom plate on the inside, the motor attached to that via the rear engine mounts.  You're looking at about 2 1/2" to 3" thick with the inside and outside lam schedules...

[seabob4]

The great thing about Inboards is the incredible simplicity of components and installation, as opposed to an I/O.  Engine and tranny, shaft, shaft log, shaft strut, rudder port.  That's it.  Of course, getting all that chit in right place?

This is a little vid that I think is kinda neat, what I used to do all the time at Stamas...http://www.youtube.com/watch?v=DD3g-BvAwh0

As you can figure, with an I/B, the transom really doesn't come into play.  We used to install what we called a rudder board, basically a shelf glassed to the transom and supported on the sides that the rudder post passed up through (and through a roller bearing), provided upper stiffness to the rudder post.  A lot of force is exerted on that rudder at speed when turning hard....

[gran398]

That's what I was getting at...the difference in the lam schedule between inboard and outboard. That is to say, how much thinner was the Genmar transom for an inboard than the same boat outboard version?

[seabob4]

Lam schedule, regardless of builder, for an inboard, is going to solid glass for the most part, probably some coremat thrown in there for a bit of stiffness.  Overall, 1/2" thick down to about a foot above the hull bottom, then of course increases in thickness where the 2 meet.

As far as Genmar goes?  It would be basically the same as I described above.  The only inboards we had in '94 were on the Wellcraft side, the 32 and 36 Martiniques, and the 33 Coastal.  Aquasport had none...in fact, not even an I/O, until the 215 Explorer was offered as an option, which I believe was around '98, maybe '97.  I really don't think the 290 SF was still in production when Genmar bought AS, but, if so, that most likely was the last I/B they built...

[Tx49]

Well, I was going to bring it up later, but since it has come up, I had some thoughts on transom replacements. It seems there are basically 2 ways to do it. One is to scarf out the inside of the existing glass and with a combination of glass and core laminates build up the transom to anywhere between 1.5 and 2.5 inches. This seems like it would hold the shape of the existing hull very good.

If i go this route I would be looking at mixing up a thinner version of fillet putty type resin and set the first layer of glass in it then add a 1/2" core ply. then glass over it with another layer of 1/2", then another layer of glass and 1/2" with a final layer of glass over the 3d layer. At 1/8" per glass layer, this would give me a total of 1/2" of new glass and another 1/8" of the existing transom glass, 1-7/8" of ply for a total thickness of 2-1/4". Would this work. i could also use 2 layers of 3/4 for a total thickness of 2".  I am a big fan of multiple thinner laminations as they provide greater strength for the same thickness of like materials. They also make for a more stable material.

My concern about doing it this way is that I am not sure how square and plumb the new cores will sit in the existing transom shell. If it is somewhat uneven in its attachment there it seems that the plane of the interior side of the transom could be off a little. could that effect the install of the outdrive or the outboards if i went that way?

The other way I have seen is to just make a pattern of the existing transom, make a new one, cut out the old and insert the new. from the standpoint of a nice new square transom, this appeals to me more, but I have concerns about the tabbing it in and retaining the hull shape.

I know that both ways are successfully done all the time, and that there are numerous threads on each method, and that it will be my decision in the end. I was just wanting to hear what are the different schools of thought?

thanks again.

[seabob4]

Glass ain't my deal Tx, but the mechanical?  Gonna go with a 350MAG and B3?

[gran398]

Tx,

The transom layup will pretty much depend on what you choose for power, as we've been chewing on.  If you go straight inboard...no need for the two inch transom layup schedule and associated cost.

BTW...where do you hail from? Please post to your avatar your home port, region group, etc.

Thanks

[Tx49]

Its a long way off for power, but yeah, Im thinking the 350 mag. Although i would rather find a 351 ford. I don't want to get into politics on a build thread, but Let's just say that i don't buy GM products.

[dburr]

Don't worry, there are a bunch of Ford fans here   My yet-to-be born grandkid's children are going to be paying for that bailout.. :ncool:  :ncool:

Windsor or Cleveland?

My vote and I know I don't have one is for the Bravo 3 or Volvo Duoprop.  Efficiency/bollard pull numbers are really nice! Just don't hit anything!

[pzart]

I wonder if you could put that new style chrysler Hemi in front of a bravo3 or volvo dualprop....I think that would be awesome

[seabob4]

Don't know about adapting the current hemi Paul, sure it could be done if someone wanted to...more likely in I/B form than I/O.  As far as dropping a Ford in, remember, Volvo was using Ford blocks up until, I think, the early 90s.  302s, 351s. and 460s.  PCM (Pleasure Craft Marine) was using them on the I/B side (Nautique (Correct Craft) used them), the Ford blocks on the I/O side were mated to OMC outdrives...