NEW boat build- weighing my options

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L&LLandServices
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NEW boat build- weighing my options

Post by L&LLandServices »

Raymond at Alumitech is currently building me a new set up, 14x8 with ss rigging and hybrid cage. side by side rear operator with triple bucket front seat. My question is, with family loaded up, cooler, and 50 gallons of gas, What motor HP/gear box/ prop combo should I run? I want to be able to comfortably point and push across wherever I want to go. Not sure though if I want to build a BBC or find someone to build me a LS.

What's the Popular dependable opinion? :banghead:

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kwanjangnihm
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Re: NEW boat build- weighing my options

Post by kwanjangnihm »

L&LLandServices welcome to SA! :salute:

If I am spending your money, it's hard to beat a Watherthunder engine!

"We have devolved a complete line of LS1, LS2, LS6, L92 and LS7 all aluminum Small Block Chevy's starting from 400 horsepower all they way up to 900 horsepower. These Engines range from 346 cubic inches all the way up to 440 cubic inches while only weighing 430 pounds."

http://waterthunder.com/

:thumbleft: :old_glory: :alabama: :rebel:
He'll cut your throat, baby, stick you in the back, drive off in your Cadillac.
He's more trouble than you think, he'll kill your sugar, leave you in the drink.

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digginfool
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Re: NEW boat build- weighing my options

Post by digginfool »

The power you can get from an LS is more than enough for a 14' boat. As far as hp/gear/prop, number one question is 'what are you going to do with the boat most of the time?' Sure, we all want that boat that will climb the Ridge fully loaded but is that practical for the couple times a year you need to do that? Will most of the time just be you and the wife or a buddy cruising or are you going on a journey that belongs on video with all seats filled most of the time? In a way, I speak from experience here. I've got a 15' Diamondback that can seat up to 7 and has a 50 gallon fuel tank. I've got an LSA on it making something in the neighborhood of 600-625 hp, running a 2.55 Ox Box and a 4 blade Sensenich NGR prop. The boat will go pretty much anywhere I point it. But, it's also an expensive boat to run. That supercharged LS likes to drink fuel and I can tell you that the engine has been run over 5,000 RPM less than 5% of the time. I know that for a fact because the computer says so and I'd bet most of that has been just getting on plane, not running miles dry, through willows or climbing ridges. I also have a 12 foot aircraft powered sled that sips fuel. Guess which one I use more? The sled because most of the time, it's just the wife and me, a cooler and we're cruising trails. So, all of that being said, the point is to build a combination that meets the needs of the way you will usually use the boat. I would start by asking Raymond what his thoughts are. Then I would call Darren at Sensenich and Patty at Whirlwind. They both have a wealth of knowledge of what works and what doesn't. As a rule of thumb, I've seen many boats exactly as you described running an LS making around 550 hp, a 2.68 gear (usually Ox or Stinger) and a 3 blade R and it is a combination that really works. I would not suggest a BBC for the sheer weight of it and the fact that you can get the power you need from an engine that barely weighs more than a Lycoming 540; the LS. Finally, you might want to put your location in your profile. There might be someone in your area that can show you their rig of similar design. In any event, I'm sure many others will weigh in and good luck with the build!
“When plunder becomes a way of life for a group of men living together in society, they create for themselves in the course of time a legal system that authorizes it and a moral code that glorifies it” - Bastiat

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digginfool
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Re: NEW boat build- weighing my options

Post by digginfool »

kwanjangnihm wrote:
Thu Nov 05, 2020 3:16 pm
L&LLandServices welcome to SA! :salute:

If I am spending your money, it's hard to beat a Watherthunder engine!

"We have devolved a complete line of LS1, LS2, LS6, L92 and LS7 all aluminum Small Block Chevy's starting from 400 horsepower all they way up to 900 horsepower. These Engines range from 346 cubic inches all the way up to 440 cubic inches while only weighing 430 pounds."

http://waterthunder.com/

:thumbleft: :old_glory: :alabama: :rebel:
Yes, what he said on the engine. I highly recommend a purpose-built engine like a Waterthunder as opposed to a crate engine conversion such as Levitator or Marine Power.
“When plunder becomes a way of life for a group of men living together in society, they create for themselves in the course of time a legal system that authorizes it and a moral code that glorifies it” - Bastiat

L&LLandServices
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Re: NEW boat build- weighing my options

Post by L&LLandServices »

I have read a lot of good things on the water thunder engines. But I just don’t know if spending 18k is worth it in the long run or not. I know Alumitech advertises the Whites Racing engines on there site but I’ve read a lot of really bad things about that company as a whole. As far as usage, my boat will spend a lot of time just cruising and fishing, we do a lot of bowfishing in the spring so the engine will spend many hours a day at an idle to 2k rpms. But on the weekends a lot of us pile up on boats and push up into the bushes a lot for backwater trail rides and beers. This is why I’ve spent multiple hours beating by head against a wall trying to figure out what my best bang for the buck is.
14x8 Alumitech , Skip White 555 big block, 82” R series 3 blade

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digginfool
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Re: NEW boat build- weighing my options

Post by digginfool »

If you are handy with tools, there's always another route to take. There's a gentleman on here that goes by loudmouse. He uses a setup where he basically takes a 6.0 LS pullout, slaps two turbos on it along with the tune he's developed and goes. If he wears out the engine, no big deal; less than $2,000.00 at the local junkyard. Obviously, he freshens the engine up before hand but let me tell you, his boat runs and you only have to do the expensive part once (turbos, plumbing, tunable fuel injection system and tuning). Don't quote me on this but if memory serves me correctly, he had less than $12K in an engine that would put out 900 hp. Something to think about.
“When plunder becomes a way of life for a group of men living together in society, they create for themselves in the course of time a legal system that authorizes it and a moral code that glorifies it” - Bastiat

L&LLandServices
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Re: NEW boat build- weighing my options

Post by L&LLandServices »

I have put some thought to that as well. maybe run E85 and Turbo or Procharger set up with some junkyard find and see how long it last. I know a guy that has a 2017 6.2l LS from a 41k mile escalade wreck for $2700. might be worth a shot throwing a turbo and holley sniper system on it and see what it does.
14x8 Alumitech , Skip White 555 big block, 82” R series 3 blade

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kwanjangnihm
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Re: NEW boat build- weighing my options

Post by kwanjangnihm »

good read on 6.0 longevity :salute:

viewtopic.php?f=48&t=66171
He'll cut your throat, baby, stick you in the back, drive off in your Cadillac.
He's more trouble than you think, he'll kill your sugar, leave you in the drink.

One Eyed Gator
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Re: NEW boat build- weighing my options

Post by One Eyed Gator »

I run a 03 6.0 on a 14x7-6 SS rigging and a hybrid cage. 2.55 oxbox with a 81.5 R blade set just before pitch mark3 - motor turns 5200.

All of the stuff I have done had been on 02-04 genIII engines built on a super tight budget.
Motor is a stock bottom end unknown milage, I did inspect the bottom end and it looked very clean, end play was within tolerance. Heads are 706's (61.5cc) heads with 2.00 intake valve. Motor comes with 317 (70cc) heads. The change with the correct head gasket gives you compression bump from 9.5 to around 10.4/5. Add a cam springs, a trunion kit and better pushrods. Easy 400hp.
Look at some Richard Holdner test and he shows more HP than that depending on the cam. You can find the 706 heads for less than 100.00. 243/799 heads flow better but are 64.5cc and yield slightly less compression.


I run an GM ASA road racing cam, was cheap, has low lift.525 but great torque curve and throttle response from 3000-5000. I use my boat for fishing the gulf usually carry a load. There is a noticable difference when adding a 3rd person both in the way the boat sits in the water and the way it runs on plane. Set like this I slow cruise in deep water at 3200 but it like to be around 3400. I have over 100 hrs on it and may run it 3500-4000 for 45 min. to 1.5hrs like this I would say they are fairly reliable. Bef0re the 6.0 I ran a stock 5.3 that had 113K on it then over 600 hrs between 2 boats.

I run a 30 gal tank and get about 2.5mpg when we are fishing. Less when playing in the marsh, think it has something to do with my right foot, lol.

Working on a 370 or 408 stroker. Got about in .030 over iron block, 799 heads with spring kit, 8qt pan, Corvette water pump. Corvette low alternator motor, LS7 lifters-trays-bolts, ARP head bolts, timing set and oil pump. Still need bearing, cranks, rods, piston-ring set, cam and proper length pushrods. What to use Molnar crank and rods with JE Piston another 2800.00

I ran a 5.3 for a while as I put together the 1st 6.0, made that swap-out and working on the next. Baby step to more HP on my budget.

WWW.car-parts.com is a good junkyard search engine but you need to know the year and model of the vehicle that has the motor you want.

BTW that 6.2 would be a great starting point.


Good luck with whatever do.

L&LLandServices
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Re: NEW boat build- weighing my options

Post by L&LLandServices »

Please tell me if I’m out of my mind...but reading through all the info posted above (thank you by the way) it seems to me I could take the 6.2- put a good set of CNC heads, a good cam, new lifters and rods, etc etc. new crank bearings. Slap on a Holley efi system with ignition controller and probably have a pretty badass motor for less than 8k. And it would be worth the gamble.
14x8 Alumitech , Skip White 555 big block, 82” R series 3 blade

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Prototype
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Re: NEW boat build- weighing my options

Post by Prototype »

Maybe so, but no telling it's future.
Motor choices are at a crossroads right now in the v gm format!
VVT eco tech gen 5 is out in 5.3 and 6.2 and makes unreal torque at below 6k stock!
Kind of real time compares to a ls3 or maybe better in stock format with the vvt.
Hard to say on this as gen 3 do breath better stock, but gen 4 have stronger lowers.
Most don't relate to fuel burn also if that's even an issue? My big block loves 8 gallons per hour at 25% race fuel. That's a 200$ day just fuel it?
My old stroker ran 3 gph on 93 but also a small hull and tuned to excess to run.
Count on 100 hours of tuning to make a good boat and motor run free after install? Or buy one that's not tuned to need under 70K!
Lots of junk out there and replacing a lower end junk yard block is not really in my cards. Dude posted that,,, must only run with friends that willing to pull him in or recover from bottom?

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