Fiberglass hardline boat will not run dry help!!

[Dmoore311]

[Dmoore311]

Boat is making rpm but just doesn’t feel like the power is there. New to the airboat game any information would help

[unforgiven11B]

A bit more information to work with would be helpful.
What engine? What prop? Direct drive or box if so what ratio? What rpm? Is this issue new? What size hull? Is your crank parallel with stringers? Does the boat plow or porpoise in deep water? Many variables come into play and the more information you can give the better chances of getting your issue resolved.

[One Eyed Gator]

Yes sir need a little bit more info and maybe a few pics.

Hartlines were originally built for the gulf, they are heavy and have a 2degree v at the rear to help them track. That is if I can remember correctly.

Buddy C1gator has a 16' x8 hartline has poly with a stock ls1 2.55 stinger and a 82" waterwalker. Boat runs very strong on the ground.

[kwanjangnihm]

Dmoore311 welcome to SA!

Its ok to come right out and say you have a CM setup. We can help from there!!

[Dmoore311]

The boat is a 2005. It’s a 502 crate engine 2:1 century reduction and Bowfishing setup(lights and what not, btw no generator on board as of now).
I’m thinking the boat is 15 foot reg is calling it a 14.
Blades are whirlwind blades 12/13 inches wide and measure 34 from the tip of the blades to where they go into the hub. If my description sucks just let me know and I’ll try to explain better. Oh and have the Polly on the bottom I think it’s 3/8s

[Dmoore311]

Rear

Side

[Andy]

Just my 2 cents. It’s hard for that prop to get any clean air..

[Dmoore311]

[Dmoore311]

I will post better pics tomorrow that’s all I had

[Deano]

Just my 2 cents. It’s hard for that prop to get any clean air...

I think that my friend Andy, very radically under estimates the value of his observation.

Normally, with radiator below (rather than above) the prop shaft, it is not creating additional blockage to the available would be air flow.
Configured such as it is, the radiator IS blocking needed air availability IN ADDITION to the rigging, fuel tank, etc.
Having a (over built?) full cage and the increased size required by using aluminum tubing, both intrinsically
decrease air flow which does in fact, make the difference in the radiator placement more pronounced.

If you can simply remount the radiator below the belt drive, that would most likely be the single biggest improvement you could make.
That could possibly create some different issues to deal with, but they would be nothing new, and could be dealt with.

Understood that your stand as it exists may complicate that endeavor.
If you could take/supply some more pictures of the belt end of the engine stand and the available
room you have to work with, that would probably be the best additional information for us to help.

[Dmoore311]

Hope this helps

1E9847372C32.jpeg[/attachment]

[Dmoore311]

[Dmoore311]

[Dmoore311]

Let me know if these are good enough thanks guys I really appreciate all the info. This boat is driving me nuts

[Dmoore311]

O

[OneBFC]

My opinion is not enough power and not enough prop. You would do well with 4 blades the longest length possible and at least 500 hp.

Not sure what you think that 502 puts out, but, if its down a bit then a heavy rig will struggle.

The air flow path is a valid think to look at as well, it does make a large difference. Though with no cage wire I am not sure it's too bad right now.

The formula never changes. 6lbs per available hp. This assumes about 3.5 to 4lbs of thrust per hp from the prop.

Ultimately you want a thrust to weight ration of around 0.5 or better. The higher that ratio the less often you get off to shake the rake.

Hope you get it sorted!

[One Eyed Gator]

Pics are fine and I understand Working with what you have within a budget.

1st it looks heavy. has a lot of nose weight with all the lights, has rod boxes and look like an extra rod box. Think the radiator looks very close to the prop. Hard to get clean air that way.
My thoughts are the radiator down low, just where I like mine and about 6-12" from the prop.

With all the lights I imagine you haul a generator for power.

Check the bottom see if it is flat. If not flat then add jack or 2 to fine tune it.

Check you motor angle as compared to the bottom. Make small adjustments as a time.

Verify your motor is tuned, Fuel pressure, jets, timing and carb linkage is correct and opening the throttle all the way.

Like ONEBFC said power to weight is king . Go through what you carry and get rid of no essential BS. I know I have to relook at everything I carry.

My buddies Hartline doesn't have the rod boxes or all the lights, 3 people it runs well.

[smokster]

that cage looks like it weighs a ton

[Dmoore311]

Will be looking into a 4 blade setup hopefully I can run 82” inch setup any thoughts. Also pitching the idea around maybe going to a fuel injection setup. Never really had much luck with carbs on any hot rod. Not sure how much airboats differ. Any thoughts. Radiator will be getting moved b4 anything else is done.

[Dmoore311]

Could I run the wider blades or what that be too much strain on that reduction(century 2:1)

[One Eyed Gator]

What is the prop length from tip to center of the hub, what is your WOT rpm and what pitch mark the blades set on?

You could also call Century and see if your belt-drive house will work with a 2.37:1 gear set

[Dmoore311]

New blades whirlwind 2.0 78”whisper tip
New carb
New distributor
Fuel system etc
You get where I’m going with this lol. Finally got to run boat yesterday. Max rpm around 4800.
Needless to say after finally running the boat, it takes awhile to get on step. Unless I’m missing something I’m just thinking the boat is wayyyy to heavy. Good Bowfishing rig, never gonna burn hills. Thanks for all the info guys.
May have to save up for that air ranger

[One Eyed Gator]

Best money to spend would be on a 2:37 belt drive some of the later models you can swap out the gears.

Call Century