Subscribe to Precision Engine
Sign up for our E-newsletter
Our injectors are from Bosch (P/N 0280 156 127). These are the taller LS1 style at about 2.917″ tall.
An intake manifold that is designed for LS2 injectors features a larger diameter injector port as compared to an LS1 manifold, so if you plan to run LS1 style injectors in an LS2 manifold, you’ll need the larger diameter lower injector O-rings at about 0.586″ O.D.
Shown here (left-to-right): LS2 injector, LS1 injector with LS1-sized O-ring and LS1 injector equipped with the larger LS2 O-ring.
This photo illustrates relative height difference. At far left is an LS2 injector (2.575″ tall) and two LS1-type injectors (2.917″ tall).
The Professional Products EFI intake was installed by torquing the 6mm socket head cap screws 44 lbs./in. on the first pass, followed by 89 lbs./in. on the second pass. After the engine reaches operating temperature, remember to go back and re-torque to 89 lbs./in.
Be sure to lubricate the injector O-rings before installing. Install carefully to avoid damaging the O-rings.
Once seated, gently rotate the injector to verify proper O-ring seating.
All eight injectors installed in the manifold and ready for the fuel rails. Note: Be sure to orient the injector connectors outboard.
Since we’re running the taller injectors (essentially running LS1 injectors in an LS2 manifold), the 0.500″ tall spacers from the Katech adapter kit are placed between the fuel rail brackets and the manifold. Note that the long slot side of the fuel rail brackets must be placed at the manifold bosses.
Closeup of a fuel rail bracket with 30mm bolt and spacer.
The front of each aluminum fuel rail accepts a 3/8″ NPT to -6 male/male fitting. This allows connection of the front crossover hose.
Always use an aluminum -AN wrench when servicing -AN hose ends to prevent marring. Here we’re using a Fragola -6 wrench.
The front ends of the fuel rails are plumbed together using -6 AN 90-degree hose ends and -6 braided hose.
Once both fuel rails are installed, and before fully tightening the fuel rail brackets, rotate each injector to verify seating, then carefully tighten the brackets.
The rear end of the right side fuel rail is plugged with an open 3/8″ NPT fitting. Here we installed a 1/8″ NPT plug in the opening. This location can easily be used at a later date to install a fuel pressure gauge.
The rear of the left fuel rail is plumbed with a 3/8″ NPT to -6 male/male 90-degree fitting to accept the fuel feed hose.
The fuel inlet hose features a 90-degree -6 male-to-locking-flare fitting. This will connect to an OE-type fuel line.
The rear of this manifold features two threaded holes. The left hole is unused so it’s plugged with a 3/8″ NPT plug. The right hole accepts a kit-supplied vacuum T-fitting. Since the center boss on this intake is blank (this is where some LS manifolds accept the MAP sensor), the MAP sensor on this application must mount at the front right of the manifold.
The MAP sensor mounts in this hole and is secured by a 4mm x 0.5 x 5mm screw (see threaded hole adjacent to the sensor probe hole).
The MAP sensor is oriented 90 degrees relative to the front of the manifold. You’ll need an OE metal bracket secured to the manifold with a 4mm screw and a tab to accept the sensor. We used a Standard Motor MAP sensor (P/N AS60).
I heated the ATI damper hub in a convection oven to 200 degrees F to ease the interference installation.
The ATI damper hub slipped on fully when heated. The ARP damper bolt (with ARP moly) was then installed and tightened to 235 lbs./ft.
The damper with integral crank pulley was installed with six 5/16″ flat-top screws, thread-locked and tightened to 16 lbs./ft. The damper holes only align in one position.
The edge of the damper is clearly marked for degrees. I’ll make and install a TDC pointer for reference.
This side view shows crank pulley alignment to the massive water pump pulley.
At this point, the engine is easily converted from/to EFI or carburetor by simply swapping intake manifolds.
Tags: -AN, ATI, BALANCER, BOSCH, DAMPER, FUEL, FUEL INJECTION, FUEL RAIL, INJECTOR, INTAKE, LS, LS2, MSD, PLUMBING, PROFESSIONAL PRODUCTS, PROJECT ENGINE
