| How-To - Engine and Drivetrain
Best Power Per Dollar for a 5.3 LS Engine?
QUESTION
Which 5.3L "Vortec" would give the best power/dollar ratio in a 1979 El Camino using fuel injection and a 4L60E trans? —Benjamin Grady Jr., via email
ANSWER
The GM 5.3L engine (326.1 ci, 3.78-inch bore 3.62-inch stroke) is by far the most-produced displacement in GM's Gen III, IV, and V family tree. There are millions of these lying around in the salvage-yard—and like all "LS"-based engines, they can produce big power even in well-used, 100,000-mile trim. The Web is chock-full of these hop-ups (Google is your friend).
Just about any 5.3L is acceptable. They're found in trucks, vans, and SUVs, often marketed as the "Vortec 5300." Try getting one that's compatible (from the same time-frame) as your 4L60E trans. That maximizes ECU compatibility, minimizing tuning issues. In fact, try to pull the engine and trans together from the complete donor vehicle as a complete matched unit. The engine could be a Gen III or even a 2010-or earlier Gen IV. However, a Gen IV may not be the most cost-effective option; depending on the application, Gen IVs could have come with AFM (active fuel management- selective cylinder deactivation) or VVT (variable valve timing), complicating retrofit and (if you want to go that route) typical hop-up mods. All Gen III/IV/V production engines are integrated into GM's VAT (vehicle antitheft system), which must be removed for retrofit use by reflashing the ECU, even if no other retuning is needed.
So, in my opinion a Gen III makes the most sense for the guy on a budget. The most numerous garden-variety Gen III 5.3 is RPO LM7 (VIN code "T" in position 8 of the serial number on the driver-side dash-pad near the windshield). Introduced in 1999, it has a cast-iron block and aluminum heads. Output in stock form varied by model year. The following is from Wikipedia:
| Gen III 5.3L "Vortec" Stock Rated-Output (SAE J1349) | ||
| Model Year | Power (HP) | Torque (LB-FT) |
| 1999 | 270 hp | 315 lb-ft |
| 20002003 | 285 hp | 325 lb-ft |
| 20042007 | 295 hp | 335 lb-ft |
There are many other Gen III 5.3L variants, but being rarer, they're likely more expensive. Moving up the fuel chain, more highly-prized variants include the 20032005 290 hp/325 lb-ft RPO LM4 (VIN "P"), which had an aluminum block in addition to aluminum heads, shaving 8090 pounds off total engine weight. Don't confuse this all-aluminum version with the rarer-yet all-aluminum Vortec 5300 HO, RPO L33 (VIN "B"). Found only in some 20052007 extended cab, four-wheel-drive, Chevy Silverado 1500 and GMC Sierra 1500 pickups, this engine uses 4.8L flat-top pistons in place of the LM7's dished pistons. More importantly, it came with casting No. 799 cylinder-heads, identical to Corvette LS6 No. 243 heads except for the latter's beefier beehive valvesprings and hollow-stem exhaust valves. LS6-style heads are among the highest-flowing cathedral-port heads, plus they have a better, redesigned D-shaped exhaust port. Minor pocket-porting really turns them on. Combined with the flat-top pistons, the heads also increase compression-ratio from 9.5:1 to 10:1. The L33 cam is also slightly hotter.
In fact, a cam upgrade is the key to awakening even the most mundane LS-based engines. For those of us bred on traditional small-blocks, the power gains are, frankly, astonishing. It is not uncommon to wind up with 400-plus hp just from a mild cam swap, a custom tune, and (if needed) larger injectors. Again, the Web is chock-full of examples; here are just two:
- Richard Holdener spent $100 on a used GM LS9 cam and valvesprings, then made 402 hp and 379 lb-ft. Note the cam was designed for a Gen IV and requires additional parts to work right in a Gen III. Engineered as it was for a rectangular-port 6.0L, supercharged application with a 122.5 LSA (lobe separation angle), this cam did cost some bottom-end torque.
- With an aftermarket cam, Jeff Smith and others have made over 425 hp with a mild Comp Cams LSR Cathedral Port hydraulic-roller (grind 269Lr HR12, PN 54-456-11). Ground on a 112-degree LSA, the duration at 0.050-inch tappet-lift is 219/227 degrees, with 0.607/0.614 inches of lift at the valve.
For fuel-injection, there are two ways to go. If you want to keep the engine stock, an OE GM ECU and harness (grab it with the takeout) works well (again, after removing the VATS) if you understand wiring. There are also aftermarket universal harnesses, such as those available through Painless Performance. Retuning can be handled using a PC-based program like HP Tuners. If you need to farm this stuff out, the price is going to be well North of $500.
Of course, there are a bunch of aftermarket engine management solutions. New on the block is Edelbrock's Pro-Flow 4 (totally redesigned compared to the previous Pro-Flow 3). Initial evaluation looks quite promising as Big E may finally have achieved a true "plug-and-play" aftermarket solution using a simple "E-Tuner" user interface tablet that's included with the system. Said to eliminate the need for laptop tuning or costly dyno sessions, it uses Bluetooth connectivity to communicate with the ECU and the kit's included Android-based tablet (or download the app for free for your cellphone).
According to Edelbrock, "A 'Setup Wizard' guides you through the initial programming for your particular engine. Once you provide the basic data (type of engine, cubic inches, firing order, cam profile), the E-Tuner then selects the most appropriate base calibration for your engine. As you drive the vehicle, the self-learning E-Tuner continually maximizes the fuel map according to the environment and your driving style, so your engine always performs at its best."
Smith is just finishing up a personal evaluation of Edelbrock's system for HOT ROD; expect a detailed report in the near future.
Posted by: elliotelliothankele0272741.blogspot.com
Source: https://www.motortrend.com/how-to/power-per-dollar-5-3-ls-engine/
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