I'd want bigger than 5.3 on an 18x8

 

What would be a reasonable size for a 5.3? By going to a smaller hull, do you give up too much displacement and surface area to be able to run loaded with fish? Is a 16x7 enough boat for 4 shooters? I'm lost as an Easter Egg when it comes to an airboat, but I know for sure that I don't want any more 4 hour "Betty White without a Snickers" episodes while we try to run dry with a 115 Yamaha. I'm glad my Mom couldn't hear me last night.:headbang:

 

Hahaha!!! If I remember right you was looking tired too. Jet boot bud. 3" water is all you need. But on my airboat I have the 6.0

 

How long is your boat? I wanna shoot off yours while the river is low. I've got gas, diesel, and full cooler.

 

so who won ?

 

It wasn't the two guys that spent most of the night pushing their boat up river. Lol

 

How dry are you talking 3to 4" of water if so build a pumper with that 5.3 it would be bad ass.

 

Airboats are all fun and games until you get one stuck, then it's a snickers commercial marathon. Blow boats are a roller coaster ride, crazy highs, crazy lows, and you're never quite sure which you're going to get when you launch :drunk:

That said if you want to haul fish get a 20x8 with tall sides and as much motor as you can afford. Scratch that, more motor than you can afford.

 

Spoken very nicely

 

When u get 1 stuck a little diesel can get her sliding again

 

But that's not environmentally safe. Lol

 

What about a 5.3 DD on a 7x12 or so? I....I mean my friend....want to give this blow boat businesses a try without breaking the bank.

 

LS motor can't handle a prop straight on the crankshaft. U have to come up with some type of thrust bearing to take the load off the crank. Dave at waterthunder just got done and is still testing a DD LS he built. Seems to be a badass for what it is. But u might could buy a thrust bearing setup from him if he's making them

 

But now if u keep that same 12x7 idea going but put a reduction.. Then u will have something

 

Is 12' long enough for a good bowfishing rig? How big does it need to be to fish 3? 4? I figured a reduction would be a must...... Just trying to get somebody else's line of thinking on a different line of thinking.:shh: It won't have to run dry, but it will need to be able to push its way in 6" or so.

 

That little LS 5.3 with about 20lb boost would make way more power than you would ever need!.

 

Now why did I have to work so hard to get that out of ya? Looks like a cheap 400 ponies to me. Talk me out of a boosted 5.3 with a cam, push rods, lifters and valve springs with 2.3:1 reduction and a 3 blade 79" Whisper Tip on a 7x18.

 

It's unbelievable what kind of HP you can get out of basically a stock 5.3(cam change and valvesprings) with some boost. Good friend of mine just got done putting one together for his Chevelle and its pretty easy to get 750-800+HP at the crank. Not sure how they would perform/last in a airboat but they've defiantly proven themselves at the track!

 

In a CHEVELLE it ain't in an airboat. There's a guy down the road with a 5.3 trans am he built that's a bad boy.. Bet it wouldn't last many trips on an average BOWFISHING airboat that gets ran. Like a little 12 ft boat in Florida would run a long time with that setup but not a boat that weighs 5 times as much + fish, generator ect..

 

With an airboat all factors come into play. The hull, issues with the hull, weight distribution and good ol horsepower

 

All great points. I have the 5.3, so that's going to be the power plant. The main reason for the 5.3 is the cost. I ordered a new prop and hub for my outboard yesterday. $400. Low mile 5.3s are $500 all day long. A few hundred more, and you are in a cam, push rods, and valve springs. I don't want an airboat. I NEED an airboat. This is simply a sacrifice to the outboard gods.
Now, what would be a good size boat for 350-400 HP?

How important are width and length?
Is a short boat hard to get on plane?
Will I be able to push 18x8 or 18x7?
Keep in mind, it doesn't need to run dry, and it doesn't need to be a speed demon.
Thanks for all the input! I don't want a turd, but I'm not going to cross the line where we end up with 10k in a motor.

 

Mine jumps on plane fine runs dry and GPS at 47 mph. I have a 78 in wood prop but as long as it's working I'm not buying a new composite. Tho Id like to.

 

My 2 cent would be a 16 foot by 102 inch beam and 7 foot bottom.
I like wide.

 

My 2 cent would be a 16 foot by 102 inch beam and 7 foot bottom.
I like wide.

This was my next question. It looks like most of the blow boats around here have near vertical sides. I like your 84" bottom and 102" beam idea. A guy would still want turning chines broke in the bottom, wouldn't he? What works best? 5* negative?

 

16ft with reduction

 

20 X 7 with a 6.0 that has cam,pushrods,valve springs, and headers. Runs great, good power, some dry, and excellent on gas. Been 47 mph with 3 guys and have hauled 400 carp

 

I have a 20 by 98 with 7 foot bottom with 502/502 and I would like some more horses after about getting stuck once.
Can only go up to 600 with my reduction, but I like to have those 98 more ponies.
:co:

 

Belt upGrade. It'll handle waaaaaay more than 600. Stop reading the tags and instructions, that's no fun!!

 

More hp with a blackhawk belt^^^^^

 

How does yours handle, Beaver? I'm going to need to be able to turn this beast.

 

Fishes great!! Doesn't turn nearly as sharp as a chined boat. That being said while fishing it doesn't seem to track like a chined boat either. For me its easier to drive this way when fishing. In any type of water current chined boats seemed to always need correcting...idk

 

More aggressive the chine the better it's gonna turn. Sliding thru a turn VS actually turning thru a turn

 

That's at 5500 rpm

 

Chined

 

Chines, don't question it. They work without them but if u building the hull then y the heck would u not, knowing it's gonna be an airboat??? That last part was for u beaver!
Some boats have a "controlled (or uncontrolled) sideways skid", some turn like a car. And everything in between. Chines determine how she turns