Fuel & Spark For LS Blocks - How It Works

Getting Fuel and Spark to Your Freshly Swapped LS Small-Block is Easier than Ever. Here’s How.

Stephen Kim Nov 17, 2011 0 Comment(s)
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Eric Blakely: Many customers already have a carburetor they like, so converting an LS motor to carburetion simplifies the swap process. All that’s required is bolting on an Edelbrock carb-style intake, and plugging the factory GM sensors into the Edelbrock ignition controller to control the spark timing. Not only do we have a dual-plane Performer RPM LS1 intake manifold, we also have a Victor Jr., a Super Victor, and a low-profile dual-quad intake. For motors with LS3-style cylinder heads, we offer a versatile Victor Jr. The Edelbrock ignition controller is a true plug-and-play module, so no programming is required. The timing curve can be changed by plugging in any of the included six timing chips into the receptacle on the timing box. The system uses the stock position sensors to precisely time the firing of each of the eight stock ignition coils. Additionally, we offer two carbureted camshafts for LS motors—a 220/230-at-0.050 grind and a 230/237-at-0.050 grind—to take advantage of the capabilities of the LS engine with our intake manifolds.

Speed Density Advantage

Rick Anderson: Factory GM computers rely on a mass airflow sensor to meter incoming air. That works very well for stock motors, but MAF sensors certainly have their limitations once a big cam or boost is thrown into the mix. A MAF sensor is hot wire that meters air very well, but the problem is that it doesn’t know which direction the air is flowing. As a result, with a big cam it can’t tell the difference between airflow into the intake manifold or reversion. This makes it very difficult to accurately dial in the air/fuel mixture at low rpm. To eliminate this problem, Holley EFI systems utilize speed density air metering. Combined with the system’s self-learning fuel strategy, which communicates with the wideband O2 sensors even at wide-open throttle, all you have to do is punch in a target air/fuel ratio into the software, and the computer takes care of the rest.

Fuel System Mods

Jesse Powell: Setting up a fuel system for EFI is easier than ever, and you should never be scared of tackling such a project. Most factory carbureted fuel systems used either a block-mounted pump or a very small external pump. As such, the easiest way for people to convert a carbureted fuel system over to EFI was by hooking up a 3/8-inch pickup tube to the gas tank, then connecting it to a big external fuel pump. The problem is that without any internal baffling in the tank or a proper sump, the pumps would often suck air and experience premature failure whenever the fuel level dropped below half a tank. As a fuel system manufacturer, Aeromotive realized that we needed to make things easier for our customers. Just handing someone a pump and saying “good luck” wasn’t going to cut it. When you do that, people tend to cut corners and the potential to make mistakes increases. In response, Aeromotive is currently developing a line of stamped, OE-like steel fuel tanks for muscle cars. These tanks will feature internal baffling trays, sending units, and an in-tank fuel pump that flows 340 lph at 43 psi. These pumps will work on both carbureted and EFI motors, and support anywhere between 200 to 1,000 hp. Mounting the pump in the tank will allow it to run cooler, and cut down on noise significantly. Best of all, the entire setup will only cost $500 to $600. Applications include first-gen Camaros, ’64-72 A-bodies, and possibly B-bodies and Tri-Fives. Look for them in early 2012. Aeromotive also offers fuel rails designed specifically for LS motors, in addition to our line of regulators. We even have quick-connect fittings to convert stock LS fuel rails to -AN fittings. CHP


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