hydrofield jaguar 8.8 rebuild

Discussion in 'Boatbuilding' started by BusterUp, Dec 24, 2014.

  1. BusterUp
    Joined: Dec 2014
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    Location: South Australia

    BusterUp Junior Member

    So I've been lurking around here for a while and I've got a few questions

    I'm fixing up an Australian built hydrofield jaguar it's a trimeran it was built in 1996 I think... but unfortunately it was badly neglected and the wood used for some of the sole and engine area. Well let's just say I only had to gerni it out. It reverted to some strange orange fungus. But the hull is made of very thick solid fiberglass with some structural wood (end grain balsa) and is still in very good condition. The sole supports are made of some strange cobbled together junk. Foam and 90 degree angle brackets made of a couple of layers of biax. I don't even know what they were thinking there was at least 6 pools of brown disgusting water under the sole in trapped areas that could never drain. I used a wet vac to clean it all out don't know what to do with that either. The previous owner put a ridiculous flybridge on it. My sawzall made quick work of that. It weighed alot too.

    My skills lie mainly in aluminum boats I've tinkered with fiberglass with some confidence but I'm most at home with aluminum


    Two initial questions

    What do you think is a good cockpit depth from the top of the gunwale to the sole? at the moment its about 30 inches (700mm) and what to make the sole supports from? I was thinking some kind of foam core but I'm open to suggestion.
     

    Attached Files:

  2. whitepointer23

    whitepointer23 Previous Member

    I would use quality construction ply and epoxy. To redo the stringers. Ply has good strength and will not have any problems if encapsulated In epoxy. Nice hull by the way. I always liked the hydrofield boats. Built like tanks.
     
  3. BusterUp
    Joined: Dec 2014
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    BusterUp Junior Member

    Yes the hull is crazy solid. It's probably 2 ton bare. I was thinking ply too. Chop out all the messy stuff they have put in and replace it with new wood. Eliminate all the areas where water collects to stop the rotting and the stinky smells

    It has one of the very very last TR2 sterndrives with a 7.1 L V8. But that thing is too far gone to bother with it (risers killed it) so I'm going to attach a 6.0 LS2 it's so much shorter than the big block I think it's going to fit under a flat floor, it would be more economical, it makes at least 80 hp more than the big block and can Rev 2000 rpm more, no distributor no carb, weighs half as much, nice electronics, and should be easy enough to attach to the stern drive. PCM sell them for V drive or direct drive so there should be the parts to join it to my velvet drive 71c.lots to think about.
     
  4. whitepointer23

    whitepointer23 Previous Member

    good move , the ls2 is a nice engine with serious power. and so much bolt on gear and cheap service parts available you can't go wrong. I watched a tv show last week where they put an ls 2 in an offroad racer in the u s, everything they needed was bought over the counter. had good tips on converting a car engine for a boat to. sounds like you are buying a full marine version anyway which will make it an easy swap. velvet drive flywheel housing should be easy. if you completely seal your new wood with epoxy rot is virtually eliminated unless someone drills a hole with out sealing it. put in nice big limber holes so you can seal them properly. I would fill them with epoxy and then drill the limber holes through the epoxy then you know the wood is fully encapsulated.
     
  5. whitepointer23

    whitepointer23 Previous Member

    a nice aluminium hard top incorporating the windscreen and sliding side windows would look a million bucks and give you some weather protection.
     
  6. BusterUp
    Joined: Dec 2014
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    BusterUp Junior Member

    I was planning on making an alloy pilot house. Have to make up a pattern and work out what looks good

    And I was going to use a automotive LS and convert it I've got all the heat exchangers pumps ect from the big block to use.

    I think I'll just chop all that junk off the hull and start again with structural ply and all epoxy

    What's a good cockpit depth. The current setup is Ok but not as the designer intended I think I'm 6 foot and it makes the gunwale just a bit lower than my hip that would make the sole about 250mm above the water line so scuppers will drain nicely and no risk of flooding from them going under does that sound Ok

    You certainly couldn't touch the water easily by bending over but you could net or gaff a fish successfully
     
  7. Mr Efficiency
    Joined: Oct 2010
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    Mr Efficiency Senior Member

    I found as a six-footer that 2 feet 3 inches is adequate for cockpit depth, as a fishing platform, in that you can brace yourself well enough. Remember that the higher you go, you raise the centre of gravity, 250mm above WL is quite a bit higher than a lot of comparable boats would have,
     
  8. BusterUp
    Joined: Dec 2014
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    BusterUp Junior Member

    Yes the hull is crazy solid. It's probably 2 ton bare. I was thinking ply too. Chop out all the messy stuff they have put in and replace it with new wood. Eliminate all the areas where water collects to stop the rotting and the stinky smells

    It has one of the very very last TR2 sterndrives with a 7.1 L V8. But that thing is too far gone to bother with it (risers killed it) so I'm going to attach a 6.0 LS2 it's so much shorter than the big block I think it's going to fit under a flat floor, it would be more economical, it makes at least 80 hp more than the big block and can Rev 2000 rpm more, no distributor no carb, weighs half as much, nice electronics, and should be easy enough to attach to the stern drive. PCM sell them for V drive or direct drive so there should be the parts to join it to my velvet drive 71c.lots to think about.
     
  9. whitepointer23

    whitepointer23 Previous Member

    if you fit side pockets in the cockpit mount them about 60 or 70 mm above the floor, then when you fish you have a built in toe hold along the bottom, for me that is by far the best way to fish when bottom bouncing, plus the natural stability of a hydrofield makes it even better. if you get the 7 mate channel in Adelaide have a look at the offroad racer show that's on every afternoon. they have all the info on wiring and fuel that you need. you can buy a loom from usa that lets you keep the ecu and get rid of everything else including the oxygen sensor. they also use a fuel filter off a corvette which takes the return fuel line and regulates the fuel at the required 91 psi. that saves you having to run extra lines back to the tank. put a marine starter and alternator on and it should be as safe as any marine engine. looking forward to following this build.
     
  10. BusterUp
    Joined: Dec 2014
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    BusterUp Junior Member

    Ah yes a space for your toes to fit. The thing is if I lower the sole the gunwale is going to be really high. This thing is super deep sided if I stand in the middle of the tank coffin I can't see over the sides. I think it being a multi hull even if the sole is higher than a mono hull the extra stability will make up for it. I think it will be fine

    I'm an auto elec and I've wired up quite a few of them. Easy as pie. a few constant powers an ignition switched input the fuel pump trigger and that's about it. You can get them with electronic throttle bodies I can do that too they communicate to the throttle with serial data that would mean no throttle cable but more complicated things to be destroyed by salty water. The ecu in the car has security that communicates with the key head they call it VATS there's software that I have that can remap them to turn off the VATS the wiring looms are pretty much good to use straight away. All the plugs are water tight the ecu lives in the engine bay in the car so it's all sealed up and there's only a few wires that you don't need from the car like the air cond and fan triggers and a whole bunch of stuff to chop off if it's auto trans

    I was just going to put the whole pump module straight into the tank it's got the surge tank the pump the level sender and the pressure regulator all built in. And all that's outside the tank is the filter and these engines don't have a return line so only one hose needed
     
  11. BusterUp
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    BusterUp Junior Member

    The fuel tank is in a separate compartment and drains to the transom not the bilge. Injected engines shouldn't leak a single drop of fuel though the starters are ignition protected standard the alternators probably are available but I would be very confident that it would be safe even without ignition protected electricals. I understand that ignition protected components aren't legally required here
     
  12. BusterUp
    Joined: Dec 2014
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    BusterUp Junior Member

    I did a fair bit of grinding and prep but I've still got a bit more to do. I've set the sole about 200mm above the waterline. I think that's pretty good. I'm working down at our River Shack and there's quite a few wooden boat builders around one straight across the road actually and quite a few come chat with me on their daily constitutionals so they take interest in my project and are approving. But they like sails and not exceeding 10kts ha ha. But here's a few more photos of you're interested and a pic of the neighbors wooden steam boat
     

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  13. Mr Efficiency
    Joined: Oct 2010
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    Mr Efficiency Senior Member

    The Hydrofield is an interesting old boat. In their original conception, the side "wings" were not truncated amidships, and the central hull continued right aft without the step, and its air vent. It was a successful enough offshore boat, unlike most cathedral hulls, which slammed mercilessly, largely because they bottomed out badly. This one maintained enough clearance in the tunnels to absorb wave impacts. But it was never a boat with much speed potential, as the wetted area was quite high, although it could hold plane at quite modest speeds. One might assume cutting off the gull wings, and the stepped hull modification, reduced that wetted area substantially, as well as altered the turning circle and handling, somewhat. Not sure this type of boat has been fully developed, and the potential maximised. The advantage it seemed to have over cats was the ability to run well with a single engine.
     
  14. BusterUp
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    BusterUp Junior Member

    This hull is a 1998 I think. It has the steps in the sides obviously but it also has some odd strakes that aren't straight and start and stop in the tunnels that must be there for a reason I don't know what for. Maybe to introduce turbulence on the surface in the tunnels. It also has a very strange arrangement at the transom where the hull has a step that goes back under the planning surface about a foot. I'm no hydrodynamasist but some crazy stuff is going on with using air to reduce drag. From the videos and photos of these boats on plane and going fast the front "sponsons" aren't even in contact with the water so the tunnels would be the parts creating the lift. Here's the only photo that shows them on my phone at the moment
     

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  15. Mr Efficiency
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    Mr Efficiency Senior Member

    The early boats from the 70's and 80's were slugs that were economical enough to power if you were prepared to cruise at 20 knots, but if you wanted 30 knots, piling on big hp was barely enough. The later versions are likely a different story.
     
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