In the first installment of our 451 cubic-inch LSX build, Late Model Engines in Houston, Texas, machined our GM Performance Parts LSX block to accept a custom set of 4.185-inch Wiseco forged pistons and a 4.100-inch stroke Callies forged crankshaft. The crew even balanced the crank in-house to jive with the Wiseco pistons and pins, Compstar H-beam rods, and a set of Total Seal rings. This go-round LME will start piecing the short-block together, which would also require the help of ARP studs to secure the mains. A Canton Racing oil pan and Melling high-volume, high-pressure oil pump will keep those mains and crank in constant supply of lubrication. These are two often-overlooked parts in an engine build, despite their great responsibility, and with higher horsepower and rpm it becomes increasingly important. To make matters worse, we have a very long stroke and expect to be eventually placing this motor in a street-going F-body with serious potential to lift the front wheels. As the oil gets sloshed around the pan during a hard launch, we'll be glad that the extra baffles in the Canton pan will be doing their job to keep the pickup in constant supply and the Melling pump will be dowsing the motor with fresh oil.
To complete the short-block we will also be using a few GM gaskets courtesy of Scoggin-Dickey Parts Center, a Rollmaster LS2 double roller timing set with a Torrington bearing and nitrided gears, and a custom hydraulic roller that LME spec'd out. Cam Motion ground our bumpstick to 254/260 duration at 0.050, 0.646/0.630-inch lift, and 114 LSA with a 110 intake centerline. LME said it should match our heads nicely (check out the top end build next issue) and should put the powerband just where you would like it for a street car that will spin up to 7,200 rpm-ideal for our intended intake manifold and reliability. The goal of this build will ultimately be to place the LSX motor into a street legal and fully functioning late-model GM, so hood/cowl clearance and durability were both factors. If you are tired of hearing all of the big-block and solid roller guys brag, keep following along and we'll show you how to wax them in a combo you can drive to and from the track with a tank full of pump gas.
Lee got started on the fully...
Lee got started on the fully machined GMPP LSX block by first inserting the LME custom hydraulic roller into the cam journals, which, as you may remember from last issue, have Durabond cam bearings. This lumpy roller was ground up by Cam Motion to rev up to 7,200 rpm, and we can't wait to hear it idle.
The crank and bearings are...
The crank and bearings are installed in the mains, a brass punch gets the crank seated properly prior to applying torque to the ARP main cap studs.
The mains are torqued with...
The mains are torqued with 60 ft-lb on the inner and outer studs, 20 ft-lb on the side bolts, using ARP moly lube and 100% pure silicone on the side bolts since they go into the crankcase.
Crankshaft endplay is checked,...
Crankshaft endplay is checked, which turns out to be 0.003-inch-right on the money.
Before putting together the...
Before putting together the rest of the rotating assembly, Lee torques the rod bolts to spec and checks both ends of the rods with the dial bore gauge-they can be honed if necessary to get them within spec. All measurements are taken and recorded, just as they were during balancing/machining.