Quote (Touhou @ Nov 11 2017 12:36am)

Yeah, it's like a ridiculous special edition that costs like 140k AUS.

Quote (FMX_89 @ Nov 10 2017 11:14pm)

Ls3

Quote (CuttingEdge @ Nov 11 2017 07:51pm)

kk thx for info FMX
Always thought it was LS7.

Save me some Googling, difference between LS3 and LS7?

Alum block on the LS7 + some valvetrain work? Or?

Quote (FMX_89 @ Nov 11 2017 10:42pm)

It's quite a big difference actually. All LSx are aluminum block. The ls3 is 365ci, the ls7 is 427ci. The ls7 heads and intake are 12° valve angle and flow significantly more than any other factory la head. Ls7 are dry sump. They turn 7,000rpm and use titanium connecting rods. It's a factory road race engine. If you are staying N/A it's an amazing platform. With a big cam and a good set of heads topped with a matched intake 600-610whp on pump gas is doable. Higher compression and E85 will go 620-630whp.

The LS3 can make 500whp with stock heads or 540whp with all of the above. It has a much stronger block for use as a power adder engine than the LS7.

Quote (CuttingEdge @ Nov 12 2017 12:13am)

Today I learned that the LS7 is actually really different compared to their truck motors.

Interesting.

Always knew iron block was better for boost though.
Aluminum has the heat dispersion, but it's just too soft.

Quote (FMX_89 @ Nov 12 2017 10:22am)

The ls3 block is the strongest of the aluminum blocks. They have held 1400whp or more for many people. The cylinder liners in the ls7 are thinner because of the huge bore size while remaining in the same bore center as the rest of the ls.

Quote (CuttingEdge @ Nov 12 2017 11:35am)

So the LS3 is alum too?
Damn didn't know that either.

Never claimed to be a Chevy guy though.

And that makes alot of sense about the LS7 being weaker for boost then.

Are they factory sleeved?

Quote (FMX_89 @ Nov 12 2017 02:53pm)

They are all aluminum blocks with cast in iron liners. LS=aluminum. Save the L33/L99/L76 and a couple other 5.3s anything that isn't LS is an iron block.

Quote (CuttingEdge @ Nov 12 2017 07:04pm)

So wait are the 5.3 truck motors NOT an LS?

I was always under the assumption that they were.

Quote (CuttingEdge @ Nov 12 2017 09:04pm)

So wait are the 5.3 truck motors NOT an LS?

I was always under the assumption that they were.

Quote

5.3 L[edit]
The Vortec 5300, or LM7/L59/LM4, is a V8 truck engine. It is a longer-stroked (by 9 mm (0.35 in)) version of the Vortec 4800 and replaced the L31. L59 denoted a flexible fuel version of the standard fuel LM7 engine. Displacement is 5.3 L (5,328 cc (325.1 cu in)) from 3.78-inch (96 mm) bore and 3.622-inch (92.0 mm) stroke. Vortec 5300s are built in St. Catharines, Ontario and Romulus, Michigan. Another engine variant, the L33, shares the same displacement, but has an aluminum block with cast in cylinder liners, much like the LS1.
LM7[edit]
The Vortec 5300 LM7 (VIN code 8th digit "T") was introduced in 1999. It has a cast iron block and aluminum heads, and can be considered the "garden variety" version of the Generation III V8s.
The 1999 LM7 engine produced 270 hp (201 kW) and 315 lb·ft of torque (427 N·m).
The 2000-2003 engines made 285 hp (213 kW) and 325 lb·ft (441 N·m).
The 2004-2007 engines made 295 hp and 335 lb·ft of torque.
The stock cam specs @ .050 duration are: 190/191 duration, .466/.457 lift, 114 LSA, 112/116 Timing
LM7 applications:
2002–2005 Cadillac Escalade 2WD
2002–2006 Chevrolet Avalanche
2003–2007 Chevrolet Express/GMC Savana
1999–2007 Chevrolet Silverado 1500
1999–2007 GMC Sierra 1500
2000–2006 Chevrolet Suburban/GMC Yukon XL 1500
2000–2006 Chevrolet Tahoe/GMC Yukon
L59[edit]
The Vortec 5300 L59 (VIN code "Z") is a flexible fuel version of the LM7. The 2002-2003 made 285 hp (213 kW) and 320 lb·ft (434 N·m), while the 2004-2007 L59s made 295 hp (220 kW) and 335 lb·ft (454 N·m).
L59 applications:
2002–2007 Chevrolet Avalanche Z71 Package
2002–2006 Chevrolet Tahoe/GMC Yukon
2002–2006 Chevrolet Suburban/GMC Yukon XL 1500
2002–2007 GMC Sierra 1500 / Chevrolet Silverado 1500
LM4[edit]
The Vortec 5300 LM4 (VIN code "P") is an aluminum block version of the LM7, and had a short production life. The LM4s made 290 hp (216 kW) and 325 lb·ft (441 N·m), It should not be confused with the L33 described below.
LM4 applications:
2003–2005 Chevrolet TrailBlazer EXT
2003–2004 Isuzu Ascender
2003-2004 GMC Envoy XL
2003–2004 Chevrolet SSR
2004 Buick Rainier
L33[edit]
The Vortec 5300 L33 (VIN code "B") is an aluminum block version of the LM7, and was referred to as the Vortec 5300 HO in marketing materials. However it should be noted that the L33 uses a flat top piston from the 4.8L instead of the standard dish piston found in the LM7. It also uses 799 cylinder heads, which are identical to the 243 casting found on the LS6 and LS2 with the exception to the Corvette spec valve springs, and hollow stem exhaust valves on the 2002-2004 LS6. This combination increased the compression from 9.5:1 to 10.0:1. The L33 also had a specific camshaft not shared with any other engine, with lobe lift of 7.2 mm, 193 degrees of intake and exhaust duration, and a 116 degree lobe separation angle. As a result, power increased by 15 hp (11 kW), to 310 hp (230 kW) and 335 lb·ft (441 N·m). It was only available on extended cab 4WD pickup trucks. Only 25% of trucks made in 2005 had the L33 engine.
L33 applications:
2005–2007 Chevrolet Silverado 1500 4WD
2005–2007 GMC Sierra 1500 4WD