Where ARE all the LSx motors hiding???
06-03-2012, 08:53 PM
#161
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I owned a 2500 hp twin turbo LSX in a race car. They are great engines, the best smallblock there is hands down, but still a small block. At that power level it was eating main bearings due to block flex and eventually breaking $4000 cranks. Enough is enough, I switched to a New Century BBC Big Chief motor and am now making 3500hp more reliably.
In a boat application the LSX can be as reliable as a big block, but the block needed (GMPP LSX block) is just as heavy as a 502 block, and will not have the low end torque that the boat needs to pull big props off idle. The other thing is that LSX engines aren't cheap like a traditional SBC, so the money advantage isn't there. They just simply aren't practical for marine performance.
In a boat application the LSX can be as reliable as a big block, but the block needed (GMPP LSX block) is just as heavy as a 502 block, and will not have the low end torque that the boat needs to pull big props off idle. The other thing is that LSX engines aren't cheap like a traditional SBC, so the money advantage isn't there. They just simply aren't practical for marine performance.
I think that most of the people reading threads like this are missing the fact that there are LOTS, more than you assume, of boats that run small blocks for power and quite simply have no room for BB power. Just because I don't have the need for a set of 1075 Mercs doesn't mean I'm going to run around flag waving saying they are useless and pointless in the marine world.
I don't think anyone is trying to replace their 1,300 hp engines in their cat with a set of these small blocks. That would obviously be pointless. Why not let the people that have a need for this product dictate the market?
Buck
06-11-2012, 12:24 PM
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I owned a 2500 hp twin turbo LSX in a race car. They are great engines, the best smallblock there is hands down, but still a small block. At that power level it was eating main bearings due to block flex and eventually breaking $4000 cranks. Enough is enough, I switched to a New Century BBC Big Chief motor and am now making 3500hp more reliably.
In a boat application the LSX can be as reliable as a big block, but the block needed (GMPP LSX block) is just as heavy as a 502 block, and will not have the low end torque that the boat needs to pull big props off idle. The other thing is that LSX engines aren't cheap like a traditional SBC, so the money advantage isn't there. They just simply aren't practical for marine performance.
In a boat application the LSX can be as reliable as a big block, but the block needed (GMPP LSX block) is just as heavy as a 502 block, and will not have the low end torque that the boat needs to pull big props off idle. The other thing is that LSX engines aren't cheap like a traditional SBC, so the money advantage isn't there. They just simply aren't practical for marine performance.
However, I think you missed the point of my initial question. I don't think anybody argues that for a max effort, high hp application...big cubes rules. Especially with boost.
BUT, for the more "average performance boater", an LS based engine would be a good replacement for a 496, or a 502....or a 525SC.
Thanks for adding value to the thread, Dave.
Last edited by Wasted Income; 06-11-2012 at 12:43 PM.
06-11-2012, 03:11 PM
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I think 2500hp pushes the limit of even the LSX block. No wonder stuff was breaking. Damn.
You can also get the RHS aluminum block for high horsepower builds though it's probably double the price of the iron LSX.
You can also get the RHS aluminum block for high horsepower builds though it's probably double the price of the iron LSX.
06-11-2012, 03:37 PM
#164
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I currently, have been daily driving my truck that I swapped the 4.8 out for a 2006 6.0. Did a cam and had the heads massaged a little bit. I hit it with 12psi on a regular basis, have been daily driving it for well over 4 years. Have done nothing but change the oil, valve springs. It makes over 650 fwhp via efi live. I would imagine it weights a bit less then a BBC, to build one is much cheaper. Stock ls cranks are good for 1000 hp, as are the blocks. I would love to see more in the marine department but the manifolds from the few I have seen are $$$$ as is the tuning that would need to go into them.
John jr
John jr
06-11-2012, 10:37 PM
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Thanks for the response, BR. I've got MUCH respect for a guy making 2500 hp with a boosted LS. Very awesome.
However, I think you missed the point of my initial question. I don't think anybody argues that for a max effort, high hp application...big cubes rules. Especially with boost.
BUT, for the more "average performance boater", an LS based engine would be a good replacement for a 496, or a 502....or a 525SC.
Thanks for adding value to the thread, Dave.
However, I think you missed the point of my initial question. I don't think anybody argues that for a max effort, high hp application...big cubes rules. Especially with boost.
BUT, for the more "average performance boater", an LS based engine would be a good replacement for a 496, or a 502....or a 525SC.
Thanks for adding value to the thread, Dave.
06-12-2012, 12:02 PM
#168
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I'm thinking something with a modest hyd. roller and 427 - 454 CI and 14-20 PSI would be more than reliable and get in the 850-900 HP area.
Is the sunny ready for a prototype Jeff?
Is the sunny ready for a prototype Jeff?
06-12-2012, 12:58 PM
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The boat is...I am....but the wife is not 
Brent and I have discussed pulling a couple plug wires off at the end of the season...." I don't know honey...something is wrong with it...time for a re-power I guess..."
Brent and I have discussed pulling a couple plug wires off at the end of the season...." I don't know honey...something is wrong with it...time for a re-power I guess..."
