Eco Nova LS3 E Rod Crate Motor Emission and Fuel System - Foul, Fresh & Fuel

Here’s our other reason; per E-Rod specs the MAF must be mounted at least 10 inches from the throttle body in the middle of a 6-inch straight section of 4-inch diameter tube. Check, check, and check on the ProFab. The good news is application-specific kits with heat shields will be available for some muscle cars, and parts are available piecemeal for custom work.

We got lucky; the engine set-back and the shape of the engine worked out nicely. We cut the last curve off of the tube, added a Spectre Performance 45-degree boot, and then used the tube we cut off to make a short connector to the GMPP-specified dry-element conical filter included in the E-Rod package.

Occasionally project cars call for resourcefulness, which is why we gathered this selection of smog fittings, elbows, lines, and ports from the local Pick-Your-Part. This was just a few dollars and will make our plumbing job much simpler.

The PCV port on the driver-side valve cover on LS3s is significantly different and much more effective than previous gen-III engines, and when properly connected will result in very minimal oil consumption. That’s definitely a priority on E-Rod packages.

Here’s the main reason we didn’t want to start from scratch. The mass airflow sensor mounting boss is specific to the sensor, and though Spectre Performance has them available, we’re not yet the best at aluminum TIG welding. This way we’re already there.

It’s important to use proper hose as well; vacuum line doesn’t cut it here. We’re running Goodyear SAE 30R7 Fuel/Emissions-rated hose for high-temp, but low-pressure use.

After fishing the hose up and around to the front of the engine, the foul air from this tube gets plumbed in with the rest of the fresh/foul air fittings. To verify the routing, we used GMPP’s own ’55 Chevy E-Rod for reference.

A brass T-hose connector joins the fresh air tube on the front of the passenger-side valve cover to the PCV valve.

The hose that connects to the right side of our T in the previous photos routes over to the inlet on the air intake. There’s no real strict placement here, it just needs to be within the air intake track situated behind the MAF sensor.

Here’s where we start getting clever; our tank vent is connected to the steel line previously used for fuel, since it’s already routed conveniently and we’ll be running new lines anyway.

Here’s another necessity that’s easy pickin’ at the junkyard. These EVAP service ports are fairly universal since they’re basically T-fittings with a screw cap on the third port. Ours even came with a nice 90-degree hose that fit the port on our purge solenoid like a glove.

[Supply] [Return] The E-Rod does not include a factory fuel pressure regulator (FPR), so we’re plumbing in an Aeromotive unit; this basic configuration is standard for many late-model OEM-type fuel rails that were originally returnless. It’s not ideal from a fuel circulation and cooling standpoint, but it’s perfectly acceptable for our purposes and can easily support way more power than we’re going to make.

There it is—the dreaded charcoal canister. In actuality, this little plastic box is not a big deal; it’s just a trap for evaporative emissions. Why do we need it? Two reasons: It handles both foul air from the purge solenoid as well as evaporative emissions from the fuel tank to form a sealed system. We fashioned a simple strap with a bolt tab to secure it into place.

Since we’re retaining the stock fuel rails, we need this special ⅜-to-AN push-on–style adapter from Aeromotive (PN 15118 for most LS series).

The canister can be mounted several ways to hide it, and we’ve got an ideal location to tuck it away down on the radiator core support between the radiator and the fenderwell. For our purge and tank vent we’re making use of some of our emissions fittings we gathered, including a legit GM quick disconnect and hose for the tank vent. The rear vent should be left open to atmosphere.

The adapter requires a reducer to mate up with our -06 Aeromotive 90-degree fitting. We ran a short length of stainless braided line from the LS3 rails over to the output side of the Aeromotive regulator.

Fuel pressure regulators should always be mounted with an eye toward minimizing the amount of braided line used, as well as for accessibility to monitor and tune the fuel pressure. Ours is on the passenger side of the firewall at roughly the same height as the fuel rails. The left line is our fuel feed line, the right line goes to the fuel rails, and the middle line is our return line. Creating braided line and AN fittings is a pain, but we have to say Aeromotive’s parts may be the easiest we’ve ever used. We didn’t perforate our fingers on the braid once!

See that bluish line at the rear of the tube? That’s the seam on the factory line. Bohlen uses and stocks only true seamless stainless tube for his work since it produces true and consistent flares every time that won’t split or leak. This factory stuff was never meant to be flared so extra care should be taken, and it’s a good idea to lightly sand the seam on the sealing surface of the flare to make it as consistent as possible.

Here’s a super useful safeguard if you’ve got any doubts about the perfection of your tube or its flare: the soft copper AN 37-degree flare seal. These aren’t necessary on quality fittings like our Aeromotive stuff, but we’ll use them where we have to interface with steel tube. Though he rarely needs them, Bohlen usually has these bits of cheap insurance in stock at Bent if you need ’em.

Prepping our stock-style pickup assembly that we retrofitted for EFI to mate up with our -06 Aeromotive fittings means we need tubing nuts and appropriate 37-degree flares on the tubes. Mark Bohlen of Bent Custom & Performance is our savior here. Bent specializes in custom metal fabrication and the nicest hard line plumbing in the hot rod industry, and he knows how to handle factory-style tubing that tends to split easily. Here he’s using his aircraft-grade flaring machine that has insanely tight tolerances, but it can be done by hand as well. We promise to bring you some real hard-line tech in a future issue with Bohlen.

Here’s one major benefit to retrofitting an E-Rod package into smog-era rod; it already has the necessary style of fuel tank. The tank needs to have a vapor dome (area that is always unfilled with fuel) of around 10 percent of total tank volume with a vent tube mounted at the highest point. Stock tanks on smog cars already have these, as contrasted with the stock-style tank for a ’68 Camaro in the background, which would not be acceptable. Now you fully understand why we worked so hard to convert our stocker to proper EFI specs.

With that machine Bohlen can knock out perfectly consistent flares in less than a minute, and without marring the tube. If you look closely you can see another issue with flaring reproduction seamed tube; it’s not always a standard size. Luckily ours was close enough to fit the die.

Here’s another benefit to smog cars: they already have emissions parts you’ll need. This circuitous steel line is our original factory drip check that prevented liquid fuel from making its way to the original charcoal canister. If you don’t have one of these, you’ll need to add a liquid check valve into the system. OK, now we gotta bolt all this stuff back into the EcoNova and get ready for the last phases of the E-Rod transformation: the trans and rearend.