Follow along as Part I takes you through the short-block machining and assembly process of a 418ci L92/LS3-based engine. Texas Speed designs the engine packages and utilizes the services of Sunset Racecraft of Lubbock, Texas, for machine work, short-block assembly, and dyno-cell testing. Founded in 1990 by Tracy Dennis, Sunset Racecraft builds and sells crate engines destined for Pro Series competition and has both advanced CNC machinery and a seasoned staff of professional engine builders.
In Part II, Texas Speed finishes assembly of the long-block and prepares the engine to be bolted up to the engine dyno where both camshaft and cylinder head changes will reveal the power potential. For you LS-series enthusiasts clamoring for an affordable and durable alternative to an LS7 for your ride, hang on-it's coming right up.
After the Sunnen hone is verified,...
After the Sunnen hone is verified, a soft hone is run through each cylinder for three to four strokes to remove any minor scratches; then the cylinder is visually inspected and checked with a dial bore gauge.
After pressure-washing the...
After pressure-washing the block, a set of Durabond CH-23 cam bearings will be installed. The front bearing is installed first. After ensuring that the oil holes in the bearing line up with the oil gallery holes in the block, a cam-bearing installation tool and a dead-blow hammer are used to drive the bearing into position. After checking that the oil holes line up correctly, the process is repeated until all bearings are installed. To ensure that the cam will operate properly, both the bearings and a "test" cam are lubricated with 30-weight oil and slipped into position to ensure that the cam rotates freely.
Target main bearing clearance...
Target main bearing clearance for the engine is 0.0020-0.0025 inch. After removing the 20 main bolts (side bolts weren't in for the procedure), a set of ACL main bearings are installed dry in the front, and the ARP 2000 series main bolts are lubricated with oil. The main caps are torqued first on the inner bolts (15 ft-lb plus 80 degrees of rotation) and then outer bolts (15 ft-lb plus 53 degrees). A main-bearing dial gauge is used to measure clearance, and the readings are transferred to the blueprint sheet.
The rotating assembly is balanced...
The rotating assembly is balanced on a Sunnen DCF-2000 electronic balancer. First, the Nos. 1 and 2 rotating and reciprocating components (two rods, bearings, pistons, pins, locks, and an oil allowance) are individually weighed, and a total bob weight for the journals is created. Since each of the Eagle forged H-beam rods showed a weight differential of less than a gram, an average rod weight is utilized.
Eagle's ESP forged 4.0-inch...
Eagle's ESP forged 4.0-inch stroke crankshaft is then mounted on the Sunnen DCB 2000 balancing machine, and the bob-weights are affixed so the computerized balancer can electronically determine where weight has to be added or subtracted on each crankshaft counterweight in order to balance the assembly.
A total of 16.2 grams and...
A total of 16.2 grams and 43.8 grams are removed from the front and rear counterweights, respectively. To relieve the weight, pilot holes are drilled; then a 5/8-inch drill bit removes metal a total of 0.400 inch deep in front and 1.0 inch in the rear.
The main bearings are lubricated,...
The main bearings are lubricated, and the Eagle crank is lowered into position. The crank is a nontwist forged unit constructed of 4340 alloy steel and features micro-polished journals and a 0.125-inch radius in the oil journals. According to Jason Mangum from Texas Speed and Performance, "The Eagle crank offers both great strength and value. We've successfully used it in forced-induction applications that exceeded 1,000 hp. The crank comes with either a 24X reluctor wheel (we used) for mid-'04 though '05 applications or the latest generation of 58X reluctor wheel."
The bearings are put into...
The bearings are put into the top of the main caps, lubricated with Red Line assembly lube, and then fit before the ARP 2000 main bolts are torqued as described earlier.
A set of Total Seal rings...
A set of Total Seal rings with a plasma-moly coated top ring, along with Napier second ring and cast-iron oil-control ring with diameters of 1.5/1.5 and 3 mm, respectively, make up the piston-ring set. A motorized piston-ring grinding machine is used to set ring gap, which is 0.021 inch on the top ring and 0.023 on the second ring.
The oil ring and scraper were...
The oil ring and scraper were installed, followed by the two top compression rings onto a set of custom-made Diamond Racing Products flat-top pistons. The forged offering uses 2618 alloy with 4cc valve reliefs and is capable of up to a 200 shot of nitrous with the specified rings. Custom pistons are available for the 418, including -10 and -28cc offerings for lower compression or boosted applications.
Eagle H-beam forged 4340 connecting...
Eagle H-beam forged 4340 connecting rods weigh a scant 620 grams and use free-floating 0.927-inch wristpins with double Spiralox retainers. ACL rod bearings are installed, and rod bearing clearance is verified to be 0.0025 inch. Assembly lube is placed on the bearing surface, and the builder prepares to install the pistons.
Before piston installation,...
Before piston installation, the bores are wiped clean, and oil is liberally applied to the piston skirts. A tapered ring compressor with a 4.080-inch diameter is used, and the crankshaft is rotated into position so that the piston and ring pack can be inserted into the bore. A rubber mallet is used to gently tap the piston down into the bore.