LS3-Based 418ci Engine Build - Big Power, Small Budget

The rod is carefully slipped over the crank's rod journal, and the rod cap is installed with ARP 2000 rod bolts, which are loosely tightened. Piston and rod installation continues until all are installed; then the rod bolts are torqued to 70 ft-lb.

After all of the rods are torqued, the bearing cap side bolts are installed (five on each side) and torqued to 18 ft-lb. Once complete, the crankshaft endplay clearance is measured; it fell within the tolerances (0.00078-0.0015 inch).

Texas Speed specified a positive 0.005 piston-to-deck height, which is verified on each piston.

Once the short-block is assembled, it goes to Texas Speed, where lead technician Joseph Potak completes the assembly of the remaining components. New GM coolant plugs and oil-gallery plugs are installed, and an F-body crankshaft oil deflector (windage tray) is prepped for installation. Due to the longer stroke of the crank, two washers are placed under the outside main bearing bolts to allow sufficient clearance between the rods and windage tray. Once the clearance has been verified, seven of the eight 8mm tray nuts are torqued to 19 ft-lb; the last is for the oil pickup, to be covered in Part II.

Before installing the oil pump and pan, the engine is turned over and a new GM crank bolt is installed into the crankshaft keyway. After ensuring the key is tapped in flat onto the keyway and the crankshaft key is aligned with the sprocket, a 15/16-inch socket is rotated until the crankshaft keyway is fully seated against the crankshaft flange.

After ensuring the dot on the crankshaft keyway is up top, a custom hydraulic roller camshaft from Comp Cams is thoroughly lubricated and gently guided into position.

The camshaft is retained with a thrust plate (GM PN 12589016), which was redesigned for the Gen IV engine family to support greater cam-plate loads. Instead of four 10mm bolts, the new hardware features four countersunk T-10 metric bolts, which are torqued to 19 ft-lb.

A new cam gear (GM PN 12576407, 24X reluctor wheel specific) and a GM LS2 timing chain (GM PN 12586482) are utilized. The camshaft is rotated so that the dowel pin lines up with the camshaft gear; the timing chain is then slipped over the gear, and the chain and camshaft gear are rotated so that the timing mark on the bottom of the cam gear lines up with the dot on the crank gear. Loctite is applied to the new ARP cam gear bolts, and the camshaft gear is torqued to 30 ft-lb. The GM timing chain is a single chain design and an excellent upgrade for LS1 (Gen III) engine builds, as it was previously sold under a C5R part number. Check back next time as Part II completes the build and the 418 is unleashed on the dyno.