E-Force Supercharger 1552

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Erik the Awful

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The LS motors have a stronger bottom end. The old 2-bolt main SBCs were only good up to about 500 hp. A 4-bolt main block might get you a up to 700 hp, but really want a main stud girdle for anything 500 hp or more.

The LS heads also have a superior architecture. The Vortec heads were the best factory heads, and they're handicapped against the better LS heads. The way you make an engine with poor flow competitive is to make torque. It's similar to the 440 vs. Hemi debate. If you're racing, there's nothing superior to a Hemi because their heads flow so well, but they can't make the torque that a 440 can.

If I were building a track car, 6.0 all day. If I'm building a truck, 5.7. If I'm throwing a chinese turbo on a junkyard motor, the LS will take the abuse. If I'm building from scratch, I'm confident I can build more performance cheaper with a 350.
 

L31MaxExpress

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So what would be the result of comparable mods to a 6 liter? Again, not being a smsrtarse or fanboi, just asking serious questions.
Peak torque on a 6.0L is in the 4,000-4,400 rpm range. Peak torque on a 5.7L is at 2,800 rpm. They make fairly equal peak torque. Comparing the marine L31 to a marine LY6 to the marine L83 5.3, the L31 makes more power under ~4,000 rpm than the LY6 and both are substantially stronger than the direct injected L83 5.3 under 4,500 rpm. Add a 1/4" of ****** aka crankshaft throw (dumb useless filter making this site all but useless by blocking ******), 1.5 points of compression and aluminum heads that flow to the 350....Lets just say the L31 becomes a powerhouse down lower in the rpm range.
 
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L31MaxExpress

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The LS motors have a stronger bottom end. The old 2-bolt main SBCs were only good up to about 500 hp. A 4-bolt main block might get you a up to 700 hp, but really want a main stud girdle for anything 500 hp or more.

The LS heads also have a superior architecture. The Vortec heads were the best factory heads, and they're handicapped against the better LS heads. The way you make an engine with poor flow competitive is to make torque. It's similar to the 440 vs. Hemi debate. If you're racing, there's nothing superior to a Hemi because their heads flow so well, but they can't make the torque that a 440 can.

If I were building a track car, 6.0 all day. If I'm building a truck, 5.7. If I'm throwing a chinese turbo on a junkyard motor, the LS will take the abuse. If I'm building from scratch, I'm confident I can build more performance cheaper with a 350.
413 and 440 were both a great RV engine and a smooth running torque producer for those massive 300s and Imperials.
 

618 Syndicate

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The LS motors have a stronger bottom end. The old 2-bolt main SBCs were only good up to about 500 hp. A 4-bolt main block might get you a up to 700 hp, but really want a main stud girdle for anything 500 hp or more.

The LS heads also have a superior architecture. The Vortec heads were the best factory heads, and they're handicapped against the better LS heads. The way you make an engine with poor flow competitive is to make torque. It's similar to the 440 vs. Hemi debate. If you're racing, there's nothing superior to a Hemi because their heads flow so well, but they can't make the torque that a 440 can.

If I were building a track car, 6.0 all day. If I'm building a truck, 5.7. If I'm throwing a chinese turbo on a junkyard motor, the LS will take the abuse. If I'm building from scratch, I'm confident I can build more performance cheaper with a 350.

Peak torque on a 6.0L is in the 4,000-4,400 rpm range. Peak torque on a 5.7L is at 2,800 rpm. They make fairly equal peak torque. Comparing the marine L31 to a marine LY6 to the marine L83 5.3, the L31 makes more power under ~4,000 rpm than the LY6 and both are substantially stronger than the direct injected L83 5.3 under 4,500 rpm. Add a 1/4" of ****** aka crankshaft throw (dumb useless filter making this site all but useless by blocking ******), 1.5 points of compression and aluminum heads that flow to the 350....Lets just say the L31 becomes a powerhouse down lower in the rpm range.
I appreciate both of your input. Makes sense to me now.
 

homeslice

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I am not at all against the 6.0. It is an adequate replacement for the 5.7. It is also newer and has more potential than the old motor.

I just get sick of people thinking that "dropping in an LS" is the cure for not being able/willing to tune a 5.7 or 7.4. As you for sure know - putting together the right package, and making it all work together is important. Many are too lazy to do the work.
replace many with most
 

homeslice

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The LS motors have a stronger bottom end. The old 2-bolt main SBCs were only good up to about 500 hp. A 4-bolt main block might get you a up to 700 hp, but really want a main stud girdle for anything 500 hp or more.

The LS heads also have a superior architecture. The Vortec heads were the best factory heads, and they're handicapped against the better LS heads. The way you make an engine with poor flow competitive is to make torque. It's similar to the 440 vs. Hemi debate. If you're racing, there's nothing superior to a Hemi because their heads flow so well, but they can't make the torque that a 440 can.

If I were building a track car, 6.0 all day. If I'm building a truck, 5.7. If I'm throwing a chinese turbo on a junkyard motor, the LS will take the abuse. If I'm building from scratch, I'm confident I can build more performance cheaper with a 350.
Love reading the last sentence here. makes me think maybe I made right decision replacing the L31 in my '96 stepside, rather than doing the LS swap. Followed L31max on installing the 151 cam, and did the 0411/24x upgrade as well. low speed torque what its all about in any truck IMO.
 

L31MaxExpress

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Love reading the last sentence here. makes me think maybe I made right decision replacing the L31 in my '96 stepside, rather than doing the LS swap. Followed L31max on installing the 151 cam, and did the 0411/24x upgrade as well. low speed torque what its all about in any truck IMO.
The 108 LSA in that cam helps it keep most if not all the stock low-speed torque of a L31. Its a shame that GM has it priced so rediculously high now.

24x is a nice upgrade too
 
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