6.0l LS2 rebuild looking for more power

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ramthisone1
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6.0l LS2 rebuild looking for more power

Post by ramthisone1 »

Hey guys-

I am getting ready to rebuild my 6.0L all aluminum LS2 and am looking to add a little more power. It is the all aluminum version out of a 2006 Trailblazer SS that has a Waterthunder provided cam (don't know anything about the grind) in it and makes and estimated 450 hp. I would like to bump that number up to around 550 hp.

What would I need to upgrade in order to hit this goal? Am I looking at a cam change and tuning, or is there more to it than that? What change in fuel consumption would I see? Also, can this be done with the stock ecu still?

Sorry for all the questions, I am a little behind the curve on how to build these newer engines! Thanks in advance for any help you guys can provide!

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Re: 6.0l LS2 rebuild looking for more power

Post by CarMotorBarge »

What RPM are you planning to run the motor when at WOT? Are you OK with a choppy idle? What gear ratio and prop are you using?
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
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sarros2004
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Re: 6.0l LS2 rebuild looking for more power

Post by sarros2004 »

Hi there,

I have the exact same engine in my rig, literally, even came out of a 2006 TBSS as well. I can't speak much to true horsepower as I never had it dynoed, but my tuner believes we have somewhere close to 500 in ours. What I can say is it kicks a Sensenich 3 Blade R over pretty good. Pitched at about 2, she spins up to 5100 rpms on the trailer. The gear ratio is a 2.3. Something that someone pointed out to me however on this sight is to not get to hung up in horsepower, most of your LS and small blocks are going to make there horsepower at 5500-6500 RPMs or so, which running at over time, will increase wear and tear. The point being low end torque is the key to pushing a larger prop and maintaining longevity. On mine, we used a custom grind cam from Brian Tooley racing, not sure of the specs, we called and told them what we were running and indicated we were looking for Max torque production at lower RPMs. With the cam, long tube headers from Norman clay, a short intake, fuel injection, and a solid tune, I believe we are close to the 500 hp range. ( And if we are not, it is more than enough for what I need) The injection system is factory, with a modified harness, and the ECM that came out of the trailblazer. I am no expert, and am very new to air boating, but have realized that horse power is not everything. A properly set up boat with matched gear ratio/prop to meet available hp, balancing of the boat, positioning of rigging, and operator experience seem to be the key to achieving desired results in on water performance. Hope you get the results you are looking for.

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Re: 6.0l LS2 rebuild looking for more power

Post by CarMotorBarge »

This is the year 2019. There is nothing wrong and minimal impact on longevity when running a properly built LS from 5500 to 6500 at WOT. The factory LS2 in the Corvette redlines at 6600 to 6800. Make sure you have a good top end and a proper tune. Running an LS at 5100 WOT with a 2.3 is actually harder on the engine because you are putting more load on it. It is easier on the engine to use more gear and run higher RPMs. Don't be scared of RPM. The load will stress the motor more than the RPMs.
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

ramthisone1
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Re: 6.0l LS2 rebuild looking for more power

Post by ramthisone1 »

CarMotorBarge wrote:
Wed Oct 30, 2019 5:52 am
What RPM are you planning to run the motor when at WOT? Are you OK with a choppy idle? What gear ratio and prop are you using?
I don't necessarily have a WOT target for the build, but rather a target for cruise RPM around 3200-3400 RPM. I am OK with a choppy idle. Right now I am running a 2.68 Stinger with an 80 inch 3 blade NGR prop set just past the 3 mark running WOT at 5000 RPM. I have had less pitch in the prop in the past, and spun the prop up to 5400 RPM, but I really like how it cruises with a little more pitch in it now.

A few more specs on the boat and how we use it. It is a 15' x 7' 6" Nighthawk fiberglass hull setup with a 2 up and 60" wide bench down in front. We usually are loaded with 4 adults and my two young kids. We run the Platte river in Nebraska and sometimes are forced to run dry on the sandbars, which we have had no problem doing up until this point. But, my kids are growing and getting bigger (and heavier) and if we are going to rebuild the engine, I figure the time is now to beef it up a little since we will be in there anyway.

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Re: 6.0l LS2 rebuild looking for more power

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PM sent

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Ramthisone
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Re: 6.0l LS2 rebuild looking for more power

Post by Ramthisone »

One Eyed Gator wrote:
Wed Oct 30, 2019 2:57 pm
PM sent
Hey One Eyed, for some reason I don’t see your PM. Could you possibly resend it?
2013 15 x 8 Nighthawk built by Platte River Airboats
6.0L LS2, 450hp, 2.68 Stinger, 80" NGR

CarMotorBarge
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Re: 6.0l LS2 rebuild looking for more power

Post by CarMotorBarge »

ramthisone1 wrote:
Wed Oct 30, 2019 12:36 pm
CarMotorBarge wrote:
Wed Oct 30, 2019 5:52 am
What RPM are you planning to run the motor when at WOT? Are you OK with a choppy idle? What gear ratio and prop are you using?
I don't necessarily have a WOT target for the build, but rather a target for cruise RPM around 3200-3400 RPM. I am OK with a choppy idle. Right now I am running a 2.68 Stinger with an 80 inch 3 blade NGR prop set just past the 3 mark running WOT at 5000 RPM. I have had less pitch in the prop in the past, and spun the prop up to 5400 RPM, but I really like how it cruises with a little more pitch in it now.

A few more specs on the boat and how we use it. It is a 15' x 7' 6" Nighthawk fiberglass hull setup with a 2 up and 60" wide bench down in front. We usually are loaded with 4 adults and my two young kids. We run the Platte river in Nebraska and sometimes are forced to run dry on the sandbars, which we have had no problem doing up until this point. But, my kids are growing and getting bigger (and heavier) and if we are going to rebuild the engine, I figure the time is now to beef it up a little since we will be in there anyway.
There is no cam available that will let the LS2 make 550 HSP at 5000 RPMs. You might be able to get a little more HSP than the WT cam at 5000, but you would need the cam specs to know for sure.

If you want to improve your cruise RPM, here are a few ideas:

1. Since you are pitched at 3, either add a fourth blade or get a larger hub to increase the prop's diameter. This will decrease your cruise RPM and increase static thrust.

2. Stroke the engine. With the proper cam, this will increase HSP at 5000.

Also what heads do you have?
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

One Eyed Gator
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Re: 6.0l LS2 rebuild looking for more power

Post by One Eyed Gator »

resent

ramthisone1
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Re: 6.0l LS2 rebuild looking for more power

Post by ramthisone1 »

CarMotorBarge wrote:
Thu Oct 31, 2019 6:16 am
There is no cam available that will let the LS2 make 550 HSP at 5000 RPMs. You might be able to get a little more HSP than the WT cam at 5000, but you would need the cam specs to know for sure.

If you want to improve your cruise RPM, here are a few ideas:

1. Since you are pitched at 3, either add a fourth blade or get a larger hub to increase the prop's diameter. This will decrease your cruise RPM and increase static thrust.

2. Stroke the engine. With the proper cam, this will increase HSP at 5000.

Also what heads do you have?
Cruise RPM right now is good, but I wouldn't mind having some more on the top end. 5000 rpm is just where the prop holds the engine now when I pitch it to get the cruise that I like. I would actually like to have some more top end available for situations where the ground gets a little uneven or sticky!

I have the stock TBSS 243 heads as well as the intake from the TBSS also.

Hopefully this additional info helps! What cams do you guys run in your LS's?

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Re: 6.0l LS2 rebuild looking for more power

Post by CarMotorBarge »

Here are my cam specs:

Image

Remember that I have 55 more cubic inches. Also I run my motor between 5800 and 6200 at WOT with an upgraded valve train.
Last edited by CarMotorBarge on Fri Nov 01, 2019 7:00 am, edited 1 time in total.
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

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Re: 6.0l LS2 rebuild looking for more power

Post by CarMotorBarge »

You could also put on some LS3 heads and an LS3 intake. With the proper cam, this would pick up some HSP. Just comes down to how much money you want to spend.
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

ramthisone1
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Re: 6.0l LS2 rebuild looking for more power

Post by ramthisone1 »

CarMotorBarge wrote:
Fri Nov 01, 2019 6:56 am
I run my motor between 5800 and 6200 at WOT with an upgraded valve train.
With your WOT at this RPM, what does your cruise end up at? Also, what Computer are you running and what gas do you run on? Here we have 87, 89, and 91/92 octane available and we are tuned to run on 87/89.

Also, you asked if I was OK with a choppy idle, can you tell me what the downsides to that would be? I've heard that it can cause some gear box chatter, but how bad is that? Are there other downsides to a choppy idle that I am not thinking of? And, do you have any video of your boat idling :D :D :D ?

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Prototype
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Re: 6.0l LS2 rebuild looking for more power

Post by Prototype »

On occasion people are suckered into a homebuilt myth that a motor or hull is all they need to fine tune an ultimate rig?
This post and answers probably proves that point to "ones" limitations or "expectations" for home built!
It also proves a point to "ones" limitations of not aspriated in cam selection or anything else to octane need.

Please help me build a budget motor with a thunder cam is about what I'm reading with 10 cents on the dollar?

3 r's ain't jack at 2 for a 6.0 even with a 2.3 behind it on 87 pump junk!
Build Healthy or Build Junk and extreme limited warranty to any advice you get here for free!

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Ramthisone
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Re: 6.0l LS2 rebuild looking for more power

Post by Ramthisone »

Prototype wrote:
Fri Nov 01, 2019 9:59 pm
On occasion people are suckered into a homebuilt myth that a motor or hull is all they need to fine tune an ultimate rig?
This post and answers probably proves that point to "ones" limitations or "expectations" for home built!
It also proves a point to "ones" limitations of not aspriated in cam selection or anything else to octane need.

Please help me build a budget motor with a thunder cam is about what I'm reading with 10 cents on the dollar?

3 r's ain't jack at 2 for a 6.0 even with a 2.3 behind it on 87 pump junk!
Build Healthy or Build Junk and extreme limited warranty to any advice you get here for free!
What in the hell are you muttering about?! Is English your second language? What is your point?
2013 15 x 8 Nighthawk built by Platte River Airboats
6.0L LS2, 450hp, 2.68 Stinger, 80" NGR

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OneBFC
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Re: 6.0l LS2 rebuild looking for more power

Post by OneBFC »

CarMotorBarge wrote:
Thu Oct 31, 2019 6:16 am

If you want to improve your cruise RPM, here are a few ideas:

1. Since you are pitched at 3, either add a fourth blade or get a larger hub to increase the prop's diameter. This will decrease your cruise RPM and increase static thrust.

2. Stroke the engine. With the proper cam, this will increase HSP at 5000.

Also what heads do you have?
Well, you could always add a Turbo and really cut down your cruise rpm as well as increase top end at the same time...

Just saying....once everyone that runs LS platform realize the value of a turbo it's going to really change things.
-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

ramthisone1
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Re: 6.0l LS2 rebuild looking for more power

Post by ramthisone1 »

OneBFC wrote:
Sat Nov 02, 2019 9:33 am

Well, you could always add a Turbo and really cut down your cruise rpm as well as increase top end at the same time...

Just saying....once everyone that runs LS platform realize the value of a turbo it's going to really change things.
I can't say the thought of adding a turbo hasn't crossed my mind. I am a big fan of turbos, I drive a turbo truck and have had turbo cars in the past. Could you explain to me why this would cut down cruise rpm, though? I am curious to know more about the mannerisms of a turbo motor that you describe. They seem to be catching on around here, as you see more of them showing up on the river each year. What is required to add a turbo and what would be the cost roughly? And what about longevity of the motor?

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Re: 6.0l LS2 rebuild looking for more power

Post by OneBFC »

In short, forced induction greatly increases power at a given rpm. If you want a lower cruise rpm, you need more usable power at that rpm so you can run more pitch or a longer prop at the same pitch. Carmotorbarge advised you cant get 550hp at 5000 rpm with any cam because you need more displacement to achieve that. Forced induction is commonly referred to as "displacement on demand" because it forces more air into the combustion chamber. More air, more fuel, more power. Larger displacement does the same thing.

There isn't a way around needing more power to cruise at lower rpm other than weight or drag reduction. But you can only go so light and so wide / long. More blades increase the required power at the lower rpm. If your engine has that power, you will also see a lower cruise rpm. However, your throttle response will be slower and your top speed will come down some. Think of engine rpm = power available and prop rpm = power required. You increase power required by the prop when you add pitch, length, blades or wider air foil shapes.

The long answer is a lot more involved so can't really say it all in a single post.

Here is a good read for what's possible. This isn't new. Been done since forever. It's just more popular these days due to advances in turbos, control systems and engine durability.

http://www.trucktrend.com/how-to/engine ... l-big-bang

Note that engine had 160k miles on it and in the end the valve train is what failed...not the bottom end.

Do some searches and read up. I think you will find its easier than ever to adopt forced induction.

As always, the tune you eventually run will play the single biggest part in longevity of the engine.
-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: 6.0l LS2 rebuild looking for more power

Post by SWAMPHUNTER45 »

The amount of dollars that you would spend to try to accomplish a sizable gain at the prop in a naturally aspirated application is a costly project.

Even with far larger displacement platforms such as the BBC or Cadillac to see a sizable gain in pitch or a few hundred rpm at the output shaft of the drive requires a lot of enhancements.

A power adder is the most cost efficient method to get a sizable gain. If you only desire the power on a rare occasion to free a stuck boat Nitrous is the most cost effective method and may be an option. If your after full time power then forced induction is screaming your name.

You may find it easier to build a new engine to your newly desired power specification and enjoy what you have on the boat now in the process. Keeping the old engine in reserve as a spare is a great insurance policy. I hate down time between builds.

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Re: 6.0l LS2 rebuild looking for more power

Post by CarMotorBarge »

ramthisone1 wrote:
Fri Nov 01, 2019 11:33 am
CarMotorBarge wrote:
Fri Nov 01, 2019 6:56 am
I run my motor between 5800 and 6200 at WOT with an upgraded valve train.
With your WOT at this RPM, what does your cruise end up at? Also, what Computer are you running and what gas do you run on? Here we have 87, 89, and 91/92 octane available and we are tuned to run on 87/89.

Also, you asked if I was OK with a choppy idle, can you tell me what the downsides to that would be? I've heard that it can cause some gear box chatter, but how bad is that? Are there other downsides to a choppy idle that I am not thinking of? And, do you have any video of your boat idling :D :D :D ?
I am running a Holley HP EFI system. The engine idles at 1,050 RPMs, but remember that I have a 2.88 gearbox ratio so the prop RPM is lower. I don't really get gearbox chatter, but the amount of gearbox chatter is definitely dependent on which brand box you use. My boat would not be a good fish gigging boat, but I didn't set it up for that. Also the engine has 11:1 static compression and will run 91 octane, but I run 93 octane.

Depending on weather and water conditions I cruise around 3200 RPMs, but the cruise RPM is a loaded question. Here is why. I am running a 2.88 gear with a 4 blade 83.5" R. I had a 2.68 Rotator previously with the same engine and turning the same prop. With the 2.68, I would set WOT at about 5400 and the prop was pitched at 2.5. I got about 3 MPG depending on how I drove.

When I switched to the 2.88, I ran the motor at 6200 WOT and added a degree of pitch to the 4 blade R. My cruise RPM went up about 200 RPMs versus the 2.68, but my fuel mileage didn't get worse. It actually might have gotten a little better.

I also have the option to increase the prop pitch by lowering WOT to about 5800. At 5800 with the 2.88, I am still turning the prop at the same RPM as the 2.68 at 5400. The difference is that I the prop has more pitch with the 2.88 and I get better fuel mileage despite having a higher cruise RPM.

My entire point is that increased cruise RPM doesn't necessarily mean more fuel usage. RPM and the parasitic drag associated with it is only one of the factors for fuel usage. Other factors are engine BSFC are various RPMs, the prop's thrust curve, how much pitch is in the prop, and how well the gear ratio matches the engines HSP curve to the thrust curve.

Sorry about the long winded answer. If you want a better cruise and more push on the hill, I still think the cheapest option is to add a fourth blade or get a larger prop hub. You have enough gear with the 2.68 to turn the larger prop and you can set WOT between 5000 and 5400 depending on what you like. You might be able to borrow a prop from somebody and try it out for free.

You could also try the turbo route. There are advantages to forced induction. 8)
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

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Prototype
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Re: 6.0l LS2 rebuild looking for more power

Post by Prototype »

Ramthisone wrote:
Fri Nov 01, 2019 10:40 pm
Prototype wrote:
Fri Nov 01, 2019 9:59 pm
On occasion people are suckered into a homebuilt myth that a motor or hull is all they need to fine tune an ultimate rig?
This post and answers probably proves that point to "ones" limitations or "expectations" for home built!
It also proves a point to "ones" limitations of not aspriated in cam selection or anything else to octane need.

Please help me build a budget motor with a thunder cam is about what I'm reading with 10 cents on the dollar?

3 r's ain't jack at 2 for a 6.0 even with a 2.3 behind it on 87 pump junk!
Build Healthy or Build Junk and extreme limited warranty to any advice you get here for free!
What in the hell are you muttering about?! Is English your second language? What is your point?
Dam, That hurts?
I often mutter stupid shit to myself but rarely include others! So nothing I said is useful in this budget 6.0 build, other than building a budget 6.0 for a thunder cam? Good luck with that Shit, because all I read is the cam for a 6.0 of unknown specs?
I'm muttering if it's a blower or supercharger cam, or NA, and who builds a budget 6.0 from free forum advice from a free 6.0 cam?
One off that killer rig and please post it's ultimate home built performance on a budget please, in a year or two.
Most prefer not to be around a 5.5-6.2 K motor in action beside it.
Love these junkyard post to what people find and think they can build on a dime asking for advice here, but none will put their kids in prop busting range of it?

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