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)


	The boring is done automatically on Rottler Boring Bar to .026 over, allowing 3 thousandths for honing. This will increase the factory 4-inch bore to 4.030 when it is finished. This is one of the few pieces in Golen's new stateof-the-art, 1,500-square-foot facility that is not made by either Sunnen or Serdi.

Golen Engine Service's decking machine

A machinist level and gauge are used to get the block within .002 before decking and resurfacing commences. Golen's decking machine uses a Windeld tray and a CBN cutter, which makes the job go by rather quickly and creates an excellent finish. For our LT1 there will be zero decking, meaning that 13 thousandths will be taken off to match the SRP pistons. Passes are made progressively slower to make the surface as smooth as possible. Machinist George Connoly says, Since LT1s have not been around too long, they are less likely to have been worked on before, allowing a great deal of consistency with the block.

Golen converts all LT1s from a two bolt to a four bolt mains

To add strength to the bottom end Golen converts all LT1s from a two bolt to a four bolt main motor. This requires that holes must be drilled into the block to accept the ARP studs. Once the surface of the main is cleaned off and the block is set into place, so are the new caps. The two 7/16s studs are tightened down on either side to keep them from moving while acting as a guide for punching and drilling to start the new holes. As drilling begins the location of each of the holes is written on the surface of the block using a Sharpie starting from the right, near corner as point zero. This ensures consistency when the caps are removed and the holes are redrilled using a larger U bit to near 7/16s. Next, the tops of the holes are counterbored using an even larger drill bit to relieve stress risers on the tops of the main bolts. Lastly, the holes are tapped using a 7/16s tap with a size 13-thread pitch.

A fitting element is used to determine the top guide shoes for the honing machine. Once the width is set and the shaft centered, the stroke is set for the LT1 block. Honing begins with a 180-grit, which will remove two to three thousandths of material that is swept away by the honing oil. The stones must be frequently taken off and rubbed together to ensure an even hone. This process is done entirely by feel, and must be periodically checked using a dial bore gauge to ensure that the cylinders are even. Once enough material has been removed, a 280-grit fine hone is used to give the cylinders a smooth crosshatch, and then brushes are used for the finishing touch.


	Honing the lifter bore can be a very important and often overlooked step. It becomes increasingly important with flat tappet cams, which will otherwise wipe out the lifter since it spins (as opposed to just moving up and down).


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