LSA reliability

Automotive powered airboat discussion.
fanofthesimplelife
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LSA reliability

Post by fanofthesimplelife »

Im looking at building a new boat soon and im not sure what power plant i want im going to be keeping this boat for a while so reliability is a big factor for me as well as power i will be putting it on a 13'6x8 ultra light hull .90 sides .125 bottom with poly i know i want an ls based power plant and it came down to a water thunder efi ls2 or a crate engine LSA with pulleys and maybe e85 but wasn't sure how reliable the LSA is on an airboat if someone who owns one could chime in that would be great thanks

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digginfool
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Re: LSA reliability

Post by digginfool »

So, being an LSA owner myself, here's my take on the engine. First, there are many people who have had good results with them. A buddy of mine uses one on his 18 ft tour boat and probably has a couple thousand hours on his by now with only one minor issue. He is very conscientious about maintenance and he has the Diacom software to monitor performance. He purchased the Marine Power package. You can reach him on FB at Cypress Outdoor Adventures. My experience has been a bit rougher. I also had the Marine Power package. I had a coil fail which they said probably was dead from day one or nearly so. I never noticed it because I never knew any different. I always felt something wasn't right but didn't discover the problem until I had over 100 hours on the engine. By that time, the cylinder was scoured. Marine Power was very good about the situation and rebuilt the engine under warranty. Since they were rebuilding the engine anyways, I sent out forged rods and pistons as well as an LS9 cam and upgraded springs. Now this part I'm about to tell you is what's really important to consider if you are planning to use this engine. First, the LSA is assembled using hypereutectic pistons and powdered metal rods. It does have a forged crank and the heads are very good. In its stock form, these components are perfectly suitable for the CTS-V, Camaro and Corvette where most of the time it's just tooling down the highway at 2,200 RPM with the occasionally blast stoplight-to-stoplight. This is not the service it will see on an airboat. The engine will be running 3,300 - 3,800 RPM, under boost and high loads, all the time. While the powdered metal rods aren't so much of an issue, the hypereutectic pistons can be. They are quite strong but brittle and will not stand up to even a small amount of detonation, especially in a supercharged application. The LSA runs 9 psi boost stock. All it takes is a bad load of fuel and some aggressive riding and your engine is going to grenade. I have the LSA because the previous engine had hypereutectic pistons and shattered a piston while I was trying to get unstuck. It was ugly. Absolutely nothing was salvageable. Now, you are talking about going with pulleys and E85. Very common with the CTS guys and, again, when you are talking 10 second blasts you can get away with it. But you won't get away with it in an airboat application. Your first call to action will be forged internals. Figure ~$3,300.00 on top of the cost of the new engine. Next, if you choose Marine Power or PCM, they use MEFI6 ECMs or later. You cannot just go out and get a tuning package to set it up to match the fuel to the upgrades. There's literally only one person that is willing to tune them and he's in California. So, you can buy and install the Holley Dominator (about $4,500.00 by the time you buy everything) and tune it yourself or buy a crate motor and use the automotive ECM. That option is probably the most cost-effective since there are readily available tuning packages out there but you're still looking at $1,100.00 to $2,500.00, depending on the vendor. None of this includes dyno time. Yes, on the surface, a supercharged motor seems like a good idea but unless you are willing to leave it stock (and you've already stated you don't intend to) and run it like you're almost on E and 20 miles from the ramp, it's probably not your best choice. If you look on this site, you will see that from my experience my advice is to buy a purpose-built engine. For only slightly more than you will pay for the LSA, you have an engine that has been developed for the application and already has the fully forged internals. There are several vendors out there supplying really nice packages, not the least of which is Waterthunder. Given your two choices, I would go with the Waterthunder, all day, every day. Just my $2.02. I've already lived 'the dream.'
“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

fanofthesimplelife
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Re: LSA reliability

Post by fanofthesimplelife »

Thank you for your reply that was exactly what I was looking for looks like my best bet will be with the WaterThunder for reliability

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OneBFC
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Re: LSA reliability

Post by OneBFC »

Don't have an opinion on LSA vs whatever, but, for sure engine on Airboat isn't under a constant "high" load. This is a common fallacy.

It's easy to prove the load isn't that high most of the time just be looking at fuel consumption while running.

1 gallon per hour is loosely equivalent to 10 hp.

Now, how many people run their boats around burning even 10 gallons per hour if it's not a heavy loaded working boat?

Right so, if 100hp is a "high load" for your potential engine, then maybe look elsewhere.

No question that it's possible to severely load an engine in an airboat. But, it's not the end all be all ultra duty test of an engine.

Heck, the little 2.0 I run pushes my 1 ton barge no problem for many years now and it's less than 1/3 the displacement of a typical LS setup.

Severe duty is not really what I would call it.

An Airboat running 30mph at 3000 to 3500 rpm and burning 7 to 8 gallons per hour is under the same load the engine in your truck is hauling your boat to the ramp at 75mph.

Good luck with whatever you choose to use.
-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
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digginfool
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Re: LSA reliability

Post by digginfool »

OneBFC, you've repeated that many times but it may not necessarily be true for every application. Using Diacom, I can monitor all aspects of my engine. I'm turning an 81.5 inch 4 blade NGR and at 3,400 RPM, a typical cruise speed for me, I'm pulling 4.1 psi boost, burning 10.73 gph. At 3,800 RPM, which is what I run when in deep water, I'm at 6.1 psi and burning 18.6 gph. That would indicate that the engine is indeed under fairly heavy load, certainly well above what it would be rolling down the highway. If it wasn't, the MAP wouldn't be so high nor would fuel consumption be either. By the time I'm at 5,000 RPM, I'm burning over 55 gph at 11.2 psi. I have seen the formulas that can approximate HP through fuel consumption. I've consistently seen estimates of half a pound of fuel per hp per hour which, for one gallon of fuel (6.1 lbs) equates to 12.2 hp for 1 gph. So, I'm pushing 130 hp at normal cruise, almost 100 hp more at 3,800 RPM (227 hp) and nearly 450 hp more just 1,200 RPM later (671 hp) using that formula. That actually fits with the way the parts I've installed should put it (estimated 675 hp). BTW, I do consider the formulated power output to be generous at best. I don't see any way a CTS or Camaro or Corvette is going to be putting that kind of load at the same RPM (although the load will converge as you approach WOT/terminal velocity); nowhere near the drag. An engine can consume quite a wide range of fuel at the same RPM depending on load. I'll stick with the fairly obvious that an airboat cruising at 3,400 RPM is burning more fuel than an automobile rolling down the highway at the same engine speed.
“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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OneBFC
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Re: LSA reliability

Post by OneBFC »

Well, your own math backs up my claim really. If running your LSA at 10.6 gallons per hour is a high load in your opinion then nothing anyone can say will change your opinion. I consider 120 to 130hp out of a 6 liter engine not so high load and that's what your using at your cruise speed. I consider 70% of maximum available power a heavy load.

You list "cruise speed" but don't give an actual speed. How fast are you going at 3400? If your burning 10 to 11 gph at 30mph that's pretty steep fuel consumption for a ride boat in my opinion, but, not unheard of i guess.

Anyway, this isn't a prove you wrong thing. It's just obvious that unless your driving 40+ mph all the time on a heavy boat that isn't running free you aren't really stressing any engine much.

Hammering wide open throttle for several minutes at a time probably is though and I don't think anyone will dispute a built engine is going to handle that better long term.

So, my stipulation is, if your running a boat that weighs around 2000lbs or so and cruise at 30mph and it's setup proper for tune, hull and prop then you are going to be loading that engine exactly the same as the engine in the truck you used to pull it to the ramp at 75mph and therefore, both engines are operating within design parameters.

It's just a simple fact and I don't see how it can be argued otherwise.

If your application requires 300+hp all the time non stop, you should probably build for that specifically and I would agree not many production auto engines will be happy at that load full time long term.
-Russ
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The only thing stopping you is FEAR
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digginfool
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Re: LSA reliability

Post by digginfool »

OneBFC, my last point sums up the argument everyone has made with you regarding this subject. An automobile, or even a truck, is under less load at the same engine speed as an airboat is for all but the lightest of boats. I would guestimate my airboat weighs in the vicinity of 3,000 lbs. Easy. Fifteen foot Diamondback with aluminum oval tube rigging and seating for 7. Fifty gallon fuel tank, LSA engine, Ballistic box. Throw in fuel, cooler, three or more people every time we go out, I'm probably pushing 3,700 lbs or more. Can't tell you exactly what my 3,400 RPM translates to but I would guess 28 - 30 mph. Top speed around 55 mph. Also, I consider 'deep water' to be anything much more than three feet. By that time, I'm not riding a cushion anymore and sitting deep in the water. When I'm on KCOL and running the skinny, I can get down around 2,800 RPM but that's about it.
“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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OneBFC
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Re: LSA reliability

Post by OneBFC »

Well, you are overstating when you say "everyone". Perhaps the same 3 people on this forum, sure. They are far from "everyone". Be fair.

I never said that an Airboat engine is at the same load as a car or truck at the same RPM. I said the engines are at the same load while cruising at normal cruise speeds for both. 30 mph for Airboat and 75mph for a truck with trailer and boat.

And that's absolutely true. No-one has shown that to be wrong here. Your own math proves my point.

At 75mph into a decent head wind my truck will burn 10 gallons per hour pulling the Airboat behind it and get 7.5 mpg. Trucks that pull campers see similar loads too and fuel usage.

Fuel burn equates to engine load very closely if the tune is correct. If an two engines are using the same fuel they are making similar power and are under similar load.

Can't escape physics.
-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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Re: LSA reliability

Post by loudmouse »

No matter which engine you choose it needs to be tuned for the application of which it is used. Forged pistons operating in an engine out of tune will die just as fast as cast pistons. Same with the rods, when the bearing gets hammered out the rod comes out the engine. It's all in the parameters which the engine operates. Gm has run quite a few of their engines at WOT for several hundred consecutive hrs without failure. The LS is a very good platform for horsepower. Also if ur engine is showing symptoms of not being happy, don't push it, limp it back find the problem and fix it. Otherwise you will be spending a lot of time on the couch while ur engine gets rebuilt.
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Re: LSA reliability

Post by CarMotorBarge »

OneBFC wrote:Well, you are overstating when you say "everyone". Perhaps the same 3 people on this forum, sure. They are far from "everyone". Be fair.

I never said that an Airboat engine is at the same load as a car or truck at the same RPM. I said the engines are at the same load while cruising at normal cruise speeds for both. 30 mph for Airboat and 75mph for a truck with trailer and boat.

And that's absolutely true. No-one has shown that to be wrong here. Your own math proves my point.

At 75mph into a decent head wind my truck will burn 10 gallons per hour pulling the Airboat behind it and get 7.5 mpg. Trucks that pull campers see similar loads too and fuel usage.

Fuel burn equates to engine load very closely if the tune is correct. If an two engines are using the same fuel they are making similar power and are under similar load.

Can't escape physics.
Had a 2004 Chevy Tahoe with the LS LM7. Got 6 MPG at 60 MPH towing a 30 foot camper. So 10 GPH. My airboat uses less fuel per hour cruising around. Can't escape physics. LOL

Diggin, maybe you need to sell that DB and get you a 5 seat sled that runs better. You would burn less fuel.
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digginfool
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Re: LSA reliability

Post by digginfool »

I've got a sled for when it's just the wife and me but when we're going to bring extra or building supplies to camp, need the DB.

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OneBFC
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Re: LSA reliability

Post by OneBFC »

ladyblackwater wrote:Diggin you well never get him to understand the truth. There is a huge difference in a truck pulling a boat and an Airboat running in the water or ground. If both were equivalent than fuel burn would pretty much be equivalent also and they are far away from each other on that. I want to see how many airboats get 10 mpg at crusie Rpm's. It's funny I'm writing this as my wife is driving down the highway pulling the Airboat with it and truck loaded down running 73mph and only turning the motor at 2000 rpm's. I have to say that's proof enough to prove his theory wrong.
Oops?

The fuel burn IS the same between the boat and the truck.

What isn't the same is the RPM. But RPM is not an indicator of engine LOAD.

Perhaps you misread?
-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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Re: LSA reliability

Post by Seven3 »

digginfool wrote:I've got a sled for when it's just the wife and me but when we're going to bring extra or building supplies to camp, need the DB.
I'm going to buy that sled back from you if you don't finish it soon :lol: The new 13 footer will be the family boat, and I'll make the 12 footer my frogger!

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Re: LSA reliability

Post by CarMotorBarge »

ladyblackwater wrote:Carmotorbarge I would have to say you had a big problem with your Tahoe because it should have got way better fuel mileage than that. I have a 2001 Suburban 4X4 with oversized tires and I get almost double that pulling a 18' Airboat that weighs close to if not over 5000lbs.
There was nothing wrong with the 2004 Tahoe I had. The camper was 8000 lbs and had more aerodynamic drag than an airboat. The fuel usage is comparable to what you got. Ended up putting 230,000 miles on that Tahoe before selling it. Only had to change oil, spark plugs, and 2 fuel pumps. That LS engine was very low maintenance.
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Re: LSA reliability

Post by CarMotorBarge »

ladyblackwater wrote:Diggin you well never get him to understand the truth. There is a huge difference in a truck pulling a boat and an Airboat running in the water or ground. If both were equivalent than fuel burn would pretty much be equivalent also and they are far away from each other on that. I want to see how many airboats get 10 mpg at crusie Rpm's. It's funny I'm writing this as my wife is driving down the highway pulling the Airboat with it and truck loaded down running 73mph and only turning the motor at 2000 rpm's. I have to say that's proof enough to prove his theory wrong.
You can't look only at MPG to determine load on an engine. Your wife is getting 7 GPH pulling the airboat at 2000 RPM. Lots of airboats get 7 GPH at 3000 RPM. To be honest, an airboat engine getting 7 GPH at 3000 RPM is actually under less stress and less likely to experience detonation than your truck getting 7 GPH at 2000 RPM. The higher RPM puts less stress on the engine. Can't ignore physics. :stirpot: :stirpot: :stirpot: :stirpot: :stirpot:
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Re: LSA reliability

Post by Uhairball »

ladyblackwater wrote:Carmotorbarge no she is not. The truck got 11.7 mpg pulling the boat at 73 mph. You can't argue with me on that because I'm the one the put the fuel in the truck. It's funny how you are telling me what my truck gets per gallon when you are not even it the truck. It shows 100% your are wrong.
I ain't got no dog in this fight, but: 73mph divided by 11.7 mpg= 6.239 GPH :shock:

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OneBFC
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Re: LSA reliability

Post by OneBFC »

ladyblackwater wrote:OneBFC please tell me how many boats you know that get 11.7 mpg at a crusie Rpm's. An Ecoturd only gets about 7 mpg. It's funny how you think they are the same and they are so far apart. Simple physics tells you that something with wheels needs less to move than something with out wheels. This tells you the stress load is way less on a vehicle than a boat.
Miles per gallon does not equate to engine load. Fuel usage rate does.

Your truck is moving at a faster speed than your boat, but at equal fuel use rate (gallons per hour) the engine is producing the same power and thus is under similar load.

Look, I don't have the energy to constantly educate you on every one of my posts.

This is the last time you will see me respond to you. No hard feelings, I just can't put this much time into one person constantly.

Best of luck to you and I mean that sincerely.

:salute:
-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

CarMotorBarge
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Re: LSA reliability

Post by CarMotorBarge »

Uhairball wrote:
ladyblackwater wrote:Carmotorbarge no she is not. The truck got 11.7 mpg pulling the boat at 73 mph. You can't argue with me on that because I'm the one the put the fuel in the truck. It's funny how you are telling me what my truck gets per gallon when you are not even it the truck. It shows 100% your are wrong.
I ain't got no dog in this fight, but: 73mph divided by 11.7 mpg= 6.239 GPH :shock:
Ladyblackwater stated:

"I want to see how many airboats get 10 mpg at crusie Rpm's. It's funny I'm writing this as my wife is driving down the highway pulling the Airboat with it and truck loaded down running 73mph and only turning the motor at 2000 rpm's. I have to say that's proof enough to prove his theory wrong."

I took the 73 and divided by 10 to get 7.3 GPH. I then rounded down to 7 to make the math easier, but in reality the 6.239 GPH still shows that an airboat engine is under less load than a truck engine pulling a trailer. Here is why.

Lets assume that a truck is getting 6.239 GPH at 2000 RPMs pulling a trailer and an airboat is using 6.239 GPH at 3000 RPMs running around the outer edge of Lake Kissimmee. Both engines are doing the same amount of work because the GPH is the same. However, the truck engine is actually under a heavier load because it is only spinning 2000 RPMs and the airboat engine is spinning 3000 RPMs. If you look at the MAP sensor on the truck it will show a higher load (less vacuum) because the butterfly on the throttle body is open wider than on the airboat. The truck engine is actually having to work harder (more load) because the RPMs are lower. This is why WT has stated in the past that a motor running a 2.68 ratio will last longer than a motor with a 2.0 ratio turning the same prop. The additional gear reduces the load for the same amount of work. Yes, you have to spin the engine at higher RPMs with the 2.68 ratio, but this is actually easier on the engine.
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Re: LSA reliability

Post by Aeon »

back to the topic... if you can make 550hp with boost or 550hp with NA. go with the NA every time.

call up WT or turnkey and get a stroked ls3. they work and there are hundreds of them out there

not saying the LSA is a bad motor its not but boosted with hyper pistons or a purpose built airboat motor... easy choice

if you call turnkey they build a lot of blown motors and can give you direction on what you need if you have to have a blower
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Re: LSA reliability

Post by loudmouse »

Got Boost! :banghead: Boosted 500hp will turn more prop than naturally aspirated if engines compare in cid and have better fuel economy if set up right.
Last edited by loudmouse on Sun Apr 22, 2018 9:56 pm, edited 1 time in total.
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Robo
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Re: LSA reliability

Post by Robo »

Back to the original question, the LS platform is a great motor, I have a Waterthunder and it is great. Back in the day I would be called a cheerleader but that goes back 10 years. I don’t remember reading a post that one of his customers was unhappy with a motor they bought from him. I would buy the same motor again. Roy

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