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Discussion Starter #1
I realize that many of you don't have an LS engine in your car, but here's a good read.

In this month's HotRod magazine, no link because they don't have the article online yet, they decided to blow up an LS engine. Specifically they have been getting accusatory letters of being LS biased, they decided to do another test of one. Their defense however was that these engines can make stupid high power and then said that they would take a junkyard 5.3, the same thing that's in my mom's 2001 Z71 Tahoe, dump a pair of 76 mm turbos on it and crank up the boost until it blows. What they were attempting to test here was the strength of the rotating assembly, or the crank, rods, and pistons which is what always blows on engines, as you all probably know.

They got a 400 dollar engine, pulled it apart to see what it looked like, cleaned up a couple rust spots, and i think widened the gap between the rings to hold up better with the boost. Because they were testing how much power could be made on the stock bottom end with a pair of turbos, they put on a set of new heads, rockers, springs, and an intake to support them. So the only thing that had been changed that would determine how much it could hold up was the ring gap.

They tested it naturally aspirated and it made, I think, about 450 horses. They then strapped a pair of turbos and air-water intercoolers and cranked up the boooost. The exact figure that they stopped at was 26.5 psi and 1200 horses on 112 octane. This is with a stock bottom end. The engine hadn't even blown up, they just ran out of time on the dyno. They were not kind to the engine either, literally running dyno runs back to back over 60 times. 1200 horses and 26.5 psi. holy shit.

After this was all done, they wondered why the power was peaking at 7,000 rpm and we know for a fact that 5.3s do not come with flat top pistons. They pulled the oil pan and found out on the connecting rods that they were actually running a 4.8. For those of you who don't want to do the math, that's a 289. Think about that, stock bottom ended 4.8 holding up to 1200 horses and 26.5 psi. That is what I'd call a well built engine.

some parts may not be right, but the hp, psi, and displacements are.
 

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I've always thought LSx motors were superior.....I don't get why people were writing in against the coverage of them....were they upset that no one's doing stories on the other manufacturer's motors? Or are they of the mindset that they think the antiquated GM motors are better....I know this is off topic to what you were posting about, but I'm just trying to understand the back story a bit..

That's freakin nuts about the results though..
 

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...because people would much rather read an article about Chrysler's underpowered V6...? lol I never understood why people hated the LS motors so much. It's a good powerhouse, and I can't think of any reason why a magazine SHOULDN'T cover it more lol
 

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Never made much sense to me either, they are great!
 

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Im one of the people that gets sick of hearing about the LS engines. Several reasons.

The car blocks are aluminum blocks, not a fan.

Everyone likes to say they are cheap to build and swap into classics, not true at all. The serpentine assembly has to be changed to a corvette or aftermarket, the oil pans dont like to fit in well. AC compressor is again in the way, motor mounts arent well refined yet. The swap mounts rarely go where you want. The wiring harness runs from 1400 to 2200 for a plug n play.

How is this cheaper than a direct replacement gen 1 SBC making equivalent HP?


I can get a 383 built by a machine shop for 1800 making roughly 400 HP all day long and have it installed in a weekend.

An LS runs around 1500-2000 for a buildable block around here not to mention most of the machine shops dont wanna touch the car blocks.
 

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From what I've read, getting a truck motor solves every one of those problems except for the harness, but just use the one from the donor vehicle and that too is solved.
 
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