6.2 ls engine options

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bbrickham
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6.2 ls engine options

Post by bbrickham »

currently waiting for our hull to start being built. Boat will be a 19X8 with 30in sides and ideally will like to run dry. with that being said im looking to make 500-550hp per what the builder thinks it will need to be able to manage running dry. so my real question is what is the best ls option to build or buy with a budget of about 10k max turn key ready to rock ecu wiring and all said and done. i know it can be done in that price range just looking for multiple routes and ideas to make it happen. Thanks!

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OneBFC
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Re: 6.2 ls engine options

Post by OneBFC »

19x8 going to be fairly heavy.

550 isn't going to cut it IMO.

4lbs of loaded boat weight per 1 hp for fairly good performance out of the water.

6lbs of loaded boat weight per 1 hp for marginal performance (you will be shaking the rake occasionally) Don't go off out in the middle of nowhere solo with this setup.

Plan accordingly. Noone ever come back here after they ignore this advice and says "man you were right! My boat is terrible on dry ground!" So you won't find much in the way of evidence to back up this claim other than....

My personal boat has a ratio of 3lbs of boat to 1 hp. I still sometimes wish I had more power available.

Good luck!
-Russ
-----------------------------------
The only thing stopping you is FEAR
400+hp Ecotec, 12x7.6 DBDO, 80" 3B Maximus, 2.3 OX,85+mph, water = purely optional
Life begins at 2 BAR, Just a good ole boy

ak375hh
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Re: 6.2 ls engine options

Post by ak375hh »

My boat is 19.5x8 with an enclosed cab. I run a big block 540 with 600hp/650ftlbs at 4800 where I turn my motor. My boat runs ground surprisingly well. Set up has a lot to do with your running. This boat runs ground better than my old 18x8. I don’t buy into the 1lb per hp guys will try and say you need. Since I put the 540 my boat hasn’t been stuck. I also think the tq band of the big block has something to do with it. I’ll post some pictures and a couple videos when I’m not at the cabin and have good service tomorrow. I’m guessing my boat at about 3800 lbs btw. Lots of guys up here in Alaska with big heavy boats running lots of ground.

Striker543
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Re: 6.2 ls engine options

Post by Striker543 »

I’ve never run an airboat in Alaska so I don’t know how difficult the ground there is to run, but what I do know is not all dry ground is the same, and you can take a boat that will run 30mph in a pasture and get it stuck in short green grass that doesn’t look bad.

My personal boat is a 14x8 weighing about 3,000lbs with 500hp. It does fairly well dry, but I also am careful about where I go. I have had it stuck on green grass. Any less horsepower and I would consider it underpowered. All that said, that is my long winded way of saying I entirely agree with onebfc: your boat will not perform well being that big with that little horsepower. You will be money ahead to save up some more money and get an engine with more horsepower from the start.

Gladesman06
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Re: 6.2 ls engine options

Post by Gladesman06 »

I can tell you that 500-550hp is going to be under powered for what you want to do with that size boat unless it's an extremely light weight build. To make that size boat run dry ground decent you need to be looking at least 650hp but better if you go over 700+hp. With that said you definitely need to make sure you have the right gear ratio and prop or it won't matter anyway. I can tell you from doing a lot of testing that a boat that big works best with a 2.55 ratio. I will also say from experience and building many of big boats that your best choice is definitely a big block. You have to remember being 19' long and 8' wide you have a huge foot print to get moving off dry. Now if you said you just want to run water I would definitely say you don't need that much HP.

SWAMPHUNTER45
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Re: 6.2 ls engine options

Post by SWAMPHUNTER45 »

If you look back through the archive of postings you will find a few postings on this topic. You will see a "formula" and a "blueprint" offered up as advice. Both are good advice and the bottom line is to push a big heavy boat you need big power and multiple wide blades.

Being someone who does this on a daily basis and having years of discussions and testing with others who push big heavy's I offer the blueprint. A purpose built 500 plus inch big GM engine mated to a 2.55 and 4 big blades as the old go to. This is a proven power combination.

Can you chose other options such as LS ? Yes you can but know that in the past the primier builder of the LS platform had recommended after 15ft to go to the big inch platform. Know this that to get reliable power to push a big heavy boat dry your gonna need a purpose built engine. If your not gonna do that then get you a pile of LS take outs and throw boost at them.

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Re: 6.2 ls engine options

Post by CarMotorBarge »

Just put any A/C motor on it. You will be fine.
14x7.5 Al David hull with 14 inch transom
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OneBFC
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Re: 6.2 ls engine options

Post by OneBFC »

ak375hh wrote:
Sat Jun 27, 2020 4:49 pm
My boat is 19.5x8 with an enclosed cab. I run a big block 540 with 600hp/650ftlbs at 4800 where I turn my motor. My boat runs ground surprisingly well. Set up has a lot to do with your running. This boat runs ground better than my old 18x8. I don’t buy into the 1lb per hp guys will try and say you need. Since I put the 540 my boat hasn’t been stuck. I also think the tq band of the big block has something to do with it. I’ll post some pictures and a couple videos when I’m not at the cabin and have good service tomorrow. I’m guessing my boat at about 3800 lbs btw. Lots of guys up here in Alaska with big heavy boats running lots of ground.
Yeah, I agree, 1lb per hp is overkill. Stick with 4lb/hp and good to go!
-Russ
-----------------------------------
The only thing stopping you is FEAR
400+hp Ecotec, 12x7.6 DBDO, 80" 3B Maximus, 2.3 OX,85+mph, water = purely optional
Life begins at 2 BAR, Just a good ole boy

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Slidin Gator
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Re: 6.2 ls engine options

Post by Slidin Gator »

CarMotorBarge wrote:
Sun Jun 28, 2020 8:45 am
Just put any A/C motor on it. You will be fine.
Even aviation folks figured out some time ago that it takes a few AV engines to fly a barge.

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ak375hh
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Re: 6.2 ls engine options

Post by ak375hh »

This is my 19.5x8 w/33” sides. Big cab. 540 bbc that I only turn 4800. It’s 600/650 at that rpm. Dunno what else to say... 500hp wouldn’t be great but I don’t believe you need 700. I sure wouldn’t go ls though...
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kwanjangnihm
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Re: 6.2 ls engine options

Post by kwanjangnihm »

CarMotorBarge wrote:
Sun Jun 28, 2020 8:45 am
Just put any A/C motor on it
that's good advice if you want that LS to get back to the dock :D

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GeeLeDouche
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Re: 6.2 ls engine options

Post by GeeLeDouche »

Why wouldnt you want an LS? amazing power to weight ratio and very reliable if built well.
16x8 Utah style hull With a Waterthunder motor W/ 2.3 CH3 reduction swinging a 3 blade 78" R.
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Re: 6.2 ls engine options

Post by EastBay »

SWAMPHUNTER45 wrote:
Sun Jun 28, 2020 7:34 am
If you look back through the archive of postings you will find a few postings on this topic. You will see a "formula" and a "blueprint" offered up as advice. Both are good advice and the bottom line is to push a big heavy boat you need big power and multiple wide blades.

Being someone who does this on a daily basis and having years of discussions and testing with others who push big heavy's I offer the blueprint. A purpose built 500 plus inch big GM engine mated to a 2.55 and 4 big blades as the old go to. This is a proven power combination.

Can you chose other options such as LS ? Yes you can but know that in the past the primier builder of the LS platform had recommended after 15ft to go to the big inch platform. Know this that to get reliable power to push a big heavy boat dry your gonna need a purpose built engine. If your not gonna do that then get you a pile of LS take outs and throw boost at them.
Hope you all are having a good time on the water. Just a ?...what do you mean by "pile of LS take outs"? I assume by "boost" you mean supercharged? Have a great time on the water this 4TH!

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Slidin Gator
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Re: 6.2 ls engine options

Post by Slidin Gator »

GeeLeDouche wrote:
Thu Jul 02, 2020 12:57 pm
...very reliable if built well.
Gee, not gonna disagree with this statement, but I'm pretty sure your Water Thunder is a budget buster here.
bbrickham wrote:
Fri Jun 26, 2020 10:00 pm
what is the best ls option to build or buy with a budget of about 10k max turn key ready to rock ecu wiring and all said and done.
As Swamp references, Water Thunder has stated previously that big boats need big blocks for reliability. There is a difference between making power occasionally (racing) and pouring on the coal continuously.
SWAMPHUNTER45 wrote:
Sun Jun 28, 2020 7:34 am
...but know that in the past the primary builder of the LS platform had recommended after 15ft to go to the big inch platform.
Let's be honest, 200 lbs of added weight is not going to make much difference on a 19' beast but can make the kind of power needed around this budget.
EastBay wrote:
Thu Jul 02, 2020 6:44 pm
Just a ?...what do you mean by "pile of LS take outs"? I assume by "boost" you mean supercharged?
EastBay, Swamp is saying go hit the junk yard for 100K mile engines and turbo/supercharge them or put them on the bottle (nitrous). They will make some power, just won't last too long, :bom: So you are gonna need a good buddy with a tow rope (as Kwan so elegantly illustrates) to get you back to the landing (a few winches if running ground) and a pile of spare engines. Oh yah, stock the boat with oil diapers for sure.
I still think I-10 is the Mason Dixon line.
2013 Mike Stossel Boats, 13' x 7' deck over, IO-540, 74" NGQ less winglets.

unforgiven11B
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Re: 6.2 ls engine options

Post by unforgiven11B »

Call water thunder, that’s a big boat. Dave has developed an LS engine package that’s purpose built for tour boats. I know the old formula and suggested bbc vs LS On a large boat, however how many tour boats are under 15’ ??? doubt enough to build a purpose driven platform.

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I Roll
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Re: 6.2 ls engine options

Post by I Roll »

That'll be pretty heavy boat. Any chance you could do with less length or shorter sides? If not, you're going to want more HP. Actually, it's the torque rating you want to be checking. You should really give some thought to BBC crate engines. For your current budget you could get a ZZ502. Out of the box their making 580 ft/lbs of torque at 3600 rpm and you'd have a 2 year warranty. However, on that set up you be much happier with a 572. If you have a Chevy dealer near you that sells performance parts, they probably have it in stock.

SWAMPHUNTER45
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Re: 6.2 ls engine options

Post by SWAMPHUNTER45 »

I Roll wrote:
Mon Jul 20, 2020 6:54 pm
That'll be pretty heavy boat. Any chance you could do with less length or shorter sides? If not, you're going to want more HP. Actually, it's the torque rating you want to be checking. You should really give some thought to BBC crate engines. For your current budget you could get a ZZ502. Out of the box their making 580 ft/lbs of torque at 3600 rpm and you'd have a 2 year warranty. However, on that set up you be much happier with a 572. If you have a Chevy dealer near you that sells performance parts, they probably have it in stock.

2 year warranty for airboat use ? Ya best check again

AT BEST you may have a 30 day warranty.

https://www.chevrolet.com/content/dam/c ... .23.19.pdf

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