Engine help on a 16X8

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islandrat
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Engine help on a 16X8

Post by islandrat » Sat Mar 16, 2019 9:34 pm

Okay, i am about to pull the trigger and order a new sled but i'm up in the air about which engine to go with. Ill be running the tx coast mostly. I'm going with a 16x8 . I am not trying to win any races i just want plenty of power to haul a load and run dry with ease. I am most concerned about reliability. I was dead set on a LSA after spending a lot of time in a friends boat this last hunting season, but now im just not so sure, i think i have done entirely too much reading online perhaps, i have just read a lot of bad things about the LSA. I have also considered the MAS LS 454, GTO just talked a buddy of mine into that engine but i have not found any info on it besides the sheets he sent him, or heard much about it. I have hared of the LSX but this is different. I have read on many threads where people recommend a purpose built LS3 over the LSA If that is the case then by what builder and what specs.

Thanks for any help

CarMotorBarge
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Re: Engine help on a 16X8

Post by CarMotorBarge » Sun Mar 17, 2019 6:35 am

What is your budget? How much HSP do you want? What RPMs do you plan to turn at WOT? EFI or carb? What prop and gear ratio?
14x7.5 Al David hull with 14 inch transom
419 CI Horsepower Barn LS3 with 2.88 Ox Box swinging 4 blade 83.5" R
GTO Rigging and B&S Tilt Trailer

islandrat
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Re: Engine help on a 16X8

Post by islandrat » Sun Mar 17, 2019 9:41 pm

id like to stay under 20 for the engine, 2.55 to 1 gear ratio, RPM's I have no clue I figured 6k WOT, preferably EFI just because I make some trips to high altitude and I've seen what that high altitude dose to carb, right now the plan is Sensenich 4 Blade 82” JR Composite Propeller but that is subject to change that was recommended with the LSA.

Sniper
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Re: Engine help on a 16X8

Post by Sniper » Mon Mar 18, 2019 1:19 pm

My SAR airboat is a 16x8 Diamondback built it for me in 2012 and I have worked 4 major floods with it and a lot of hrs just handling local issues and I have the PCM LSA engine in it and all I have done to it has been changing the oil and put gas in it and I did up grade the electric water pump for the supercharger oh and I put one set of spark plugs in it, I have had zero problems with it , very reliable engine with plenty of power and my boat because its a rescue boat is heavy
Sniper You can run but why die tired, If you heard my shot you were not the target
DOI Airboat Instructor/ Airboat Search & Rescue Specialist

CarMotorBarge
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Re: Engine help on a 16X8

Post by CarMotorBarge » Mon Mar 18, 2019 3:22 pm

For a 4 blade JR, I would recommend a 2.68 ratio. I would also recommend getting an EFI aluminum LS from a builder near you. You don't have any crazy expectations. A stroked LS3 with the Holley HP EFI and a little cam is hard to beat.
14x7.5 Al David hull with 14 inch transom
419 CI Horsepower Barn LS3 with 2.88 Ox Box swinging 4 blade 83.5" R
GTO Rigging and B&S Tilt Trailer

Aeon
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Location: Orange county-- the wrong one. I'm in California

Re: Engine help on a 16X8

Post by Aeon » Mon Mar 18, 2019 7:46 pm

My 17x8 has a stroked ls3 close to 600hp, spinning a 2.55 and a 3 blade jx. Its a big heavy boat but runs very very good :)

Not saying the lsa is bad but you can make good power with a stroked ls3 or even better a stroked ls7 but then you get into more money.
Turnkey engines built mine 4 years ago and its still going strong.
17x8 Circle H powered by a TurnKey LS3, 2.55 ox box and 82" 3 blade JX

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GeeLeDouche
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Location: Northern Utah

Re: Engine help on a 16X8

Post by GeeLeDouche » Wed Mar 20, 2019 9:19 am

I have a 550hp Waterthunder Ls2 on my 16x8 Utah style airboat and it does very well. I run a CH3 2.3 and 3 blade R series. I could run it a little higher rpm than I do, but I keep it around 5K max to keep my cruise rpm down and it does everything I could want.
16x8 Utah style hull With a Waterthunder motor W/ 2.3 CH3 reduction swinging a 3 blade 78" R.
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17-51 Legend craft w/pods pushed by a MB HD7000

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