Displacement On Demand: Part I, Golen Engine Service Creates a Bigger and Better LT1

Displacement On Demand
Part I: Golen Engine Service Creates a Bigger and Better LT1(Continued)

Based on the balancer's measurements, holes are drilled into the counterweights with rags placed on the crank so that the excess material doesn't throw off the machine.

Based on the balancer's measurements, holes are drilled into the counterweights with rags placed on the crank so that the excess material doesn't throw off the machine. A reference table tells the operator how deep to drill in order to remove the desired weight, however, the outside material is heavier than the inside material making this hardly exact. About 10 grams of material is removed at a time from the specified counterweight occasionally having to rotate the crank and drill new hole, yet careful not to Swiss cheese the crank too much. The whole process takes a great deal of finessing and achieving zero gram inches of imbalance is near impossible, but Dan manages to get us below a gram.

At last the crank is miked before jet washing and then different bearings are used when necessary to compensate for the tight or loose fit of the mains. Perfect clearance is .0022 except for the rear cap, which is .0029.

With the new bearings treated to a healthy coating of assembly lube, the crank is lowered into place; the caps placed over it and the ARP studs are torqued to 75 lb.-ft. one last time.

At last the crank is miked before jet washing and then different bearings are used when necessary to compensate for the tight or loose fit of the mains. Perfect clearance is .0022 except for the rear cap, which is .0029. When the crank goes in it should take little force to move it with a proper installation and clearance. With the new bearings treated to a healthy coating of assembly lube, the crank is lowered into place; the caps placed over it and the ARP studs are torqued to 75 lb.-ft. one last time.

The pistons are assembled by lubing the pin boss, then threading the floating wrist pin through the piston and connecting rod with the tang facing away from the valve pockets. Next the spiral locks are put into place both by hand and with a at head screwdriver. The last step is removing the ARP rod bolts and installing the bearings and oil rings. The ring gap is calculated using a table provided by the manufacturer (18 thousandths in this case) and then the rings are cut to those specifications.

The cam bearings must go in first and then be hammered in with a cam bearing installation guide before the new Comp Cams roller is carefully slid into place.

The cam bearings must go in first and then be hammered in with a cam bearing installation guide before the new Comp Cams roller is carefully slid into place. The holes in the cam bearing must line up just right to allow the passage of oil. Golen uses a cam with the lobes ground down to check to see that the cam spins okay before the real one is put in.

The LT4 timing chain is installed next so that the rods don't wind up hitting any of the cam lobes.

The LT4 timing chain, which Golen sources from nearby Dobles Chevrolet, is installed next so that the rods don't wind up hitting any of the cam lobes.
The keyway needs to be notched for the hub to t on the snout of the crank. Once this is complete the timing gear is hammered into place and the new 5/16s timing gear bolts are torqued to 25 lb.-ft. Pin pullers are sometimes needed to pull the pin further out of the cam to fit the Optispark.

The cylinders are cleaned then greased with Lubriplate to enable the installation of the pistons.

The cylinders are cleaned then greased with Lubriplate to enable the installation of the pistons. Using the butt end of a rubber mallet and a ring compressor, the pistons slide into the cylinders. The rod ends are placed around the crank; the bolts lubed with ARP moly lube then tightened with 50 ft-lbs. The final checklist is run though and the shortblock is complete. Check us out next time, as part II of our Golen LT1 build covers completing the 383 LT1 build.

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This article was originally published in the March 2005 issue of GM High Tech Performance and is copyrighted by Primedia Inc., All Rights Reserved.
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