BB Chevy Camshaft Drive, Dry Belt, Installation Instructions

1. Check that you have all the correct parts.

2. Check the front of the crankshaft for forging flash. Be sure the seal ring flange on the back of the crank sprocket will fit over the shoulder the sprocket bottoms against. Sometimes there is forging flashing here and can cause trouble. DO NOT install at this time. Be sure the seal ring fits the seal in the cover.

3. Install the cover on the front of the block with only the crankshaft installed. Be sure the cover fits flat against the gasket surface. Be sure the ten 1/4-20 x 7/8" long screws do not bottom out in the threads of the block.

4. Loosen the two 1/4-20 X 1" long pinch bolts and remove the threaded cam endplay adjustment nut. Be sure the "O" ring behind the thread in the cover has some grease on it and remains in the cover.

5. Remove the cam sprocket from the cam hub. Install the cam hub on your camshaft. Be sure the bolts do not bottom out in the threads of the cam.

6. Install the cam in the block and determine how much shim is needed to align the cam lobes with the lifter bores. Remove the cam, select an appropriate perforated shim, stick it to the block side of the cam hub with grease and reinstall the cam. A minimum of one .016 shim is needed.

Timing Dot Alignment
7. Put the tapered aluminum donut on the cam hub. Put a little lube on the seal surface. Stick the .016 solid brass shim inside the back recess of the cam-adjusting nut with a little grease. Install the cam-adjusting nut, with the seal in it, into the cover and tighten with a spanner socket until the cam has no endplay. Back off and tighten the pinch bolts. Each mark on the adjustment nut is .004". The cam should have about .010" endplay.

8. Install the crank sprocket on the crankshaft. Be sure chamfer on bore and seal ring goes toward the shoulder. Put a little lube on the seal surface. All crank sprockets should be pushed on with an installer. Aluminum crank sprockets can be warmed in an oven to 250 degrees F maximum before installing.

9. Set the crank to TDC on #1 cylinder. Set the cam at TDC on the overlap. (Intake and exhaust lifters on #1 cylinder the same height.) The dowel pin in the cam should be at 3 o'clock.

10. With the belt wrapped around both sprockets, install the cam sprocket. The timing dots on the cam sprocket and the crank sprocket front flange should line up. Put a little grease on the eccentric bushing to hold it in place.

11. Lube the three 5/16-24 12pt bolts and washers. Be sure the chamfer on the ID of the washer goes toward the head of the bolt. Torque bolts to 30 ft-lbs. maximum. Check your cam timing as you normally would. The eccentric bushing has plus/minus 6 degrees of adjustment. Each mark is 2 degrees.

12. The water pump may require modification or spacers to clear the belt and cam sprocket. Be sure to check the water pump drive belt alignment, if you space out the water pump.