1991 Runabout Restore

[bananas4jesus]

Hi my brother and I 19 and 21 years old are attempting to restore a boat that was rendered garbage. the stringers were rotten, the transom also and some of the flooring. the floor is torn out now and we were wondering what wood to use for the stringers and the floor and the transom. it is a 20' Bluewater Runabout. there are no mechanical parts so our idea is to rebuild the Camaro 350 Block that we have in the garage with a marine rebuild kit. and then to find an Alpha 1 outdrive system since that is what it had are these good ideas or no? Why? we have never done any boat work before so this is going to be an experience for us, but we are confident that we can with a little guidance.

 

[Chris1956]

Re: 1991 Runabout Restore

I recommend you use some pressure-treated 2x lumber for the stringers and frames. See if you can determine what the size of the originals was, and duplicate it. Make sure the wood is dry-stick it in the attic rafters for a while to dry it out. The transom is usually two layers of plywood laminated with poly resin, cloth and brass/ss wood screws. When everything is cut and ready to go, glass the stringers and frames to the hull, and cover them with glass and resin. There are a number of books on this subject, I recommend you read one. The concepts are not too unusual, but why should you need to reinvent it?

As for the motor. You need to cut out the transom to receive the transom plate of the Alpha 1 drive. You need two side motor mounts for the V-8. The motor itself needs to have a MARINE: carb, exhaust system, fuel pump, alternator, water pump, thermostat housing and thermostat. If you cannot get these parts used, it will cost you over $1500 to buy them at a discount price.

Could you use a 150HP outboard instead? It might be cheaper.

 

[bananas4jesus]

Re: 1991 Runabout Restore

what is the difference between a marine carb and a normal? the rest of the stuff we can get used at a local dismantler, this too but we have one we were thing we would use a 750 cfm edelbrock. would that work or no?
there is fiberglass behind where we are going to do the repair on the transom. and it is already cut for the Alpha 1, we want to stay away from outboard because we have small siblings, cousins and nieces and nephews that we will be taking out, and we are planning to use it for tubing and skiing. I know we will shut it off when they are back there but we have paranoid parents. thanks for the advice so far.

 

[tashasdaddy]

Re: 1991 Runabout Restore

marine carbs have flame arrestors, and when they over flow the don't dump gas on top of the engine, is the 1st basic diffference. fire safety. as with a other marine componets.

 

[Chris1956]

Re: 1991 Runabout Restore

bananas, If ithe transom is already cut for the Alpha, it is likely the rest of the boat can be built up for the engine.

The "Marine" difference on the carb, starter, solenoids, alternator has to do with the spark arrestor or fuel isolation properties. The electrical parts are specially designed not to create a spark. The fuel parts are specially designed to not spill fuel into the bilge, where it can explode.

 

[MelLandry]

Re: 1991 Runabout Restore

You may want to check the crank and the cam on that 350. Marine engines need high low-end torque to get up on plane and pull tubers and that engine is likely designed for a higher torque peak for useable acceleration power in a sports car. Marine components are more like truck engines.

 

[JasonJ]

Re: 1991 Runabout Restore

Before you start spending cash, do a lot of research. The outdrive could be a very spendy item to get. Not to mention the engine rebuild and then locating the manifolds, risers, marine grade alternator, distributor, cap, rotor, and carb. Then there is of course the expense of the hull rebuild. You could easily drop $4000+ getting this boat going.

This is where the outboard comes in. During your hull rebuild, you could beef up the transom and glass in some braces from the transom to the stringers. You could then insall a bracket and mount the outboard. As far as safety goes, there is no difference between an outboard and an I/O, the prop is in the same place, they are equally dangerous. the only truely safe boat is a jet boat, second is a straight inboard with the prop under the boat.

Now, based on your age, I am guessing the goal of this boat is to eventually be a tow boat with a tower for wakeboarding and skiing. For this application, the I/O would be better suited, but it will cost you a bunch of green. Maybe consider looking into getting another boat that is closer to what you want without as much work? They are out there, unless you really like this hull...

 

[ondarvr]

Re: 1991 Runabout Restore

I hate to say it, but it will cost you more to try and put it together than to buy one that's in better condition. JasonJ's $4000+ is probably low and if you work fast, it might be done by next summer. Old fiberglass boat hulls are almost worthless even in fair condition, it's all the stuff you don't have that costs money.

 

[crunch]

Re: 1991 Runabout Restore

I recommend you use some pressure-treated 2x lumber for the stringers and frames. See if you can determine what the size of the originals was, and duplicate it. Make sure the wood is dry-stick it in the attic rafters for a while to dry it out. The transom is usually two layers of plywood laminated with poly resin, cloth and brass/ss wood screws. When everything is cut and ready to go, glass the stringers and frames to the hull, and cover them with glass and resin. There are a number of books on this subject, I recommend you read one. The concepts are not too unusual, but why should you need to reinvent it?

As for the motor. You need to cut out the transom to receive the transom plate of the Alpha 1 drive. You need two side motor mounts for the V-8. The motor itself needs to have a MARINE: carb, exhaust system, fuel pump, alternator, water pump, thermostat housing and thermostat. If you cannot get these parts used, it will cost you over $1500 to buy them at a discount price.

Could you use a 150HP outboard instead? It might be cheaper.

If your PT 2x4's are "pond dry" like they are around here, you best screw them down to the rafters to dry.... if you don't they will be only good to carve airplane propelers out of.

 

[Chris1956]

Re: 1991 Runabout Restore

Crunch, What great idea, I have been using the to make longbows, and already have plenty. I could make some propellors for small airplanes. Must be a better market.

On a serious note, the reason the Wright Brothers succeeded in being first to fly was their superior propeller. Nothing else about their plane was unique.

 

[tommays]

Re: 1991 Runabout Restore

If you cant get a Compleat drive line Your going to go BROKE buying the bits and pieces of linkage and other small parts

50 here 100 there pretty soon your talking real money


Tommays

 

[AlanR]

Re: 1991 Runabout Restore

Dont use a car motor buddy I made that mistake... I had a 502 Caddy motor in my sidewinder... it had the jetdrive and everything I had it fan cooled, open headers and she sounded so sweet on the land. I dropped her in the lake and hopped in. She ran a little rough but sounded nice. I got her out in the lake by idleing and everything was going good. I started to give it gas and it was coughing and wezzing and then started to go when we got more level, I had it about 2300 Rpm and i was crusing about 16 Mph... Wow eh i thought for like 300 hp i would be hustle-ing. So i opened her up and she wennt to about about 3700 rpm and that was it. She started to knock real bad and i thought the rod was gonna go threw the side of the motor and everything was sounding tinny then she just stopped. I went to hit the starter because i thought she stalled. She was seized up soild I couldnt even get a crow bar on the fly wheel to turn it because it was so seized. what happed was i Over reved it and it siezed up before the connecting rod came threw the side of the motor. This happend because the cam was set up to be a touqey motor and wasnt ment to rev or for that matter hold a steady Rpm for a long period of time. So I learned my leason the hard way. Theres a huge diffrence between a car motor and a boat motor. Like my story above the cams are alot diffrent and they over heat because there not water cooled and to match up a set of water cooled exhausted would just be more of a hassle. So if you can find a whole motor and drive assembly it would be alot easyier. I hope you read my post before you ruin that 350 in your boat.

 

[rottenray6402]

Re: 1991 Runabout Restore

Bannas you maybe able to find a complete motor and drive much cheaper than pieceing. Someetimes they will advertise complete units out of burnt or other wise totalled boats. It would be much cheaper fixing fire damage rather than starting from nothing. Alan, there are no car engines that are designed to be water cooled that will run without liquid being pumped through them. The type of cam would not cause the seizing but no water in the cooling jackets will! I bet it smelled really bad!:'(

 

[JasonJ]

Re: 1991 Runabout Restore

Alan, I am hoping by "fan cooled" you meant that there was an onboard radiator with a fan mounted to it and there was coolant flowing through its veins.

There a five billion fanboats in Florida that use auto engines with radiators and do just fine. At the core, an automotive 350 and a marine 350 are differentiated by their ability to prevent corrosion and to inhibit spark and fuel leakage. A 4 bolt 350 longblock will do fine. What it needs to be used in a marine appication is corrosion resistant freeze plugs, a marine carburator, and a marine distributor. It also needs a cam grind that allows for low end torque and an ability to hold rpms in its powerband, wherever that may be. It also needs either an open cooling system that uses lake water and has a corrosion resistant water pump or a closed cooling system that uses a heat exchanger to cool the antifreeze with lake water. The exhaust can just go out of open headers like those 70s speedboats with the Berkley jet drives or the exhaust needs to be more traditional in that it is expelled through a system that keeps the exhaust styem cool. These are all bolt on parts.

He could use that 350, but he would be better off selling it and trying to find a complete drive train that is compatible for the boat or to find a boat that has a drivetrain. For me, the drivetrain is what makes or breaks the deal. I need to either have a motor to put on or there needs to be a motor in the boat I am getting. Otherwise it is cost prohibitive to start with an empty hull....

 

[AlanR]

Re: 1991 Runabout Restore

Yup the stock Caddy rad was used to cool it, Also i ment to say that i ran it about 3700 rpm for about 10 mins. It just wouldnt hold the RPMs cause it was starting to knock. It really needed a marine cam. it wouldnt go any more than 3700 cause it was starten to come apart

 

[JasonJ]

Re: 1991 Runabout Restore

There may have been something wrong with the jet drive. Maybe the impeller was damaged or it was not an opitmal drive for the motor. Big Block motors are not meant to spin high rpms anyway. Even if you had a "marine" cam, you would have had the same result. A marine cam is not much different than an RV/Truck cam grind. What makes an engine spin high rpms is a light reciprocating assembly, roller rockers, roller lifters, a light flywheel. Besides, you don't need high rpms with a big block. The shear torque it produces allows for greater pitch in a prop or for greater pressure in a jetdrive. Its an interesting situation you had. Its too bad, that would have been a fun ride if it worked out right...

 

[AlanR]

Re: 1991 Runabout Restore

Yeh i thought so the jetdrive was from a v6 Jetboat (odd) and its the only one i had. Prob the wrong gearing. I thought it woulda atleast done 30 mph but she struggled to do 25. Maybe ill pick up a merccrusiser stern drive cause i think I still have the sidewinder in the back of my lot so maybe ill pull it out and give it another go. I also got a 72 caddy Eldorado with a 472 so maybe ill try sticken my 472 in my sidewinder . I also had a v8 350 In my sidewinder and it broke the motor mounts out of the floor and jammed my throttle wide open, I ended up on some ones front lawn (is wasnt hurt) but it was sure as hell fun Lol. d