Displacement On Demand: Part II, Building the LT1s Top End For 400-Plus Ponies

		Displacement On Demand Part II: Building the LT1s Top End For 400-Plus Ponies (Continued)

	The valve seats are then ground down using the Serdi to t the new 2.00 and 1.55-inch valves. After the valves are back cut, the three-angle valves are inserted.


	The valves are lapped to ensure that they are seated properly. Exhaust valves should meet the seat in the middle third of the face for street cars, so that they do not get burned up. The intake on both street and race cars can be fairly close to the edge as heat is not a factor. The pointer is used to line up the edge of the cutter with the valve to ensure the proper angle.

The heads are vacuum tested to makes sure each one of the valves is sealing properly. Seven BAR indicates proper sealing. Using pipe cleaners and cleaning solvent, burrs and excess material are removed from the valve guides. Then the valves are placed in each one of the guides and moved up and down to make sure everything moves smoothly without resistance.

The heads are placed in the Sunnen decking machine and lined up within a few thousandths.

The heads are placed in the Sunnen decking machine and lined up within a few thousandths. In the end, the resurfaced heads will make a perfect union to the resurfaced block, strengthening the seal and lessening the chance of a blown head gasket. Lastly, the heads must be cleaned in the Jet Wash before assembly.

The water pump drive seal onto the end of the crank, and then the oil pump.

Dan installs the water pump drive seal onto the end of the crank, and then the oil pump. Before he installs the oil pump, though, he TIG welds the pick up tube to the oil pump. With the oil pump installed Dan places silicone at all four corners where the oil pan attaches to the block and on top of the oil pan gasket. Then he bolts up the oil pan using approximately 10 lb.-ft. of torque or until they feel snug, so as not to cause the cork gasket to bulge out. Sometimes with stroker kits there is a clearance issue with the oil pan, but the stock GM LT1 Camaro pan fits fine. The shortblock is topped off with a couple coats of paint.

The LT1 will utilize Manley stainless steel 2.00/1.55 valves, as well as Comp Cams steel spring cups and retainers.

Although the photo is soft, that's no reflection on the valvetrain hardware. The LT1 will utilize Manley stainless steel 2.00/1.55 valves, as well as Comp Cams steel spring cups and retainers. High Energy 5/16-inch, stock length chrome moly pushrods are plenty sturdy enough for most applications, but when needed can be upgraded to a Hi-Tech or other one-piece pushrod. This package also comes with Comp Cams 1.5 ratio rocker arms and double valve springs capable of supporting .580-inches of lift, not to mention 1.6-ratio rockers in case the customer might later want to upgrade.

The spring seats are put into place and the valve height is checked using the installation tool. Copper-coated steel shims are used to achieve the proper height before the valve springs are installed.

With the heads all cleaned up it is time to begin assembly. Dan measures the spring heights by bringing them to coil bind, which in this case is specified as 1.135. Next it is backed off 80 thousandths, and that number is multiplied by the lift to get the install heights for both the intake and exhaust. The pressure must be checked at this height to make sure the spring will work. The intake spring pressure will have to be higher than the exhaust spring since the springs are heavier. These springs use the stock spring seats so it works well in this application. Oil is placed in all the valve guides and the valves are worked back and forth to spread the oil evenly. The spring seats are put into place and the valve height is checked using the installation tool. Copper-coated steel shims are used to achieve the proper height before the valve springs are installed.

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