Engine Break-In Guide - Break-In Without Breakin'

To listen for any mechanical problems such as valvetrain noise (and meet city noise regulations), a relatively quiet set of mufflers is required. We scraped up a set of D-port Hooker Super Competition Headers and Floyd Hand mated them with a pair of Dynomax Super Turbo mufflers via a Jegs header collector flange kit, Flowmaster Venturi reducer cones, and four feet of Jegs 2.5-inch-diameter, aluminized exhaust tubing. Almost any exhaust will work as long as it seals and is quiet.

Floyd used a strong LED light to inspect the front and rear barrels of the Cliff Ruggles-built, 800-cfm carb to confirm that no foreign matter got into them during set up. Since the valve covers were just placed over the valvetrain in preparation for pre-oiling, he also visually inspected the top of the cylinder heads and rocker arms for any debris.

The spark plugs were then removed in preparation for turning the engine over and to inspect them for wear, oil, or any abnormal condition that would indicate the engine wasn't running properly when it was first broken in. All of the plugs looked fine.

To ensure that the rotating assembly still turned over properly, a 15/16-inch socket was fitted to a 1/2-inch-drive break-over bar and the engine was rotated past the zero mark on the harmonic balancer a total of four times. The distributor hold down clamp was removed and the engine was rotated until we got to top dead center (harmonic balancer mark reads zero). Since the zero mark could either be TDC or a full 180 degrees out, we inserted a finger in the No. 1 (driver side, furthest forward) spark plug hole and slowly rotated the engine in a clock-wise direction to feel for a puff of air as the balancer approached the zero timing mark. Both of the intake and exhaust rockers were loose, which indicates TDC. (If one rocker is loose while the other is tight, keep rotating the engine one full revolution until you get to TDC.)

We pulled the distributor cap and marked the location of the rotor before removing the distributor. Note this rotor is pointed at the No. 1 spark plug wire (if the distributor cap was installed). Another neat trick is that if the distributor is equipped with a vacuum advance, the initial timing will be approximately 10-12 degrees if the end of the vacuum advance hose fitting is pointed right in the middle of the driver-side, rear cylinder-head freeze plug.

The oil pump will be primed so that oil is pumped through the engine and can be seen flowing to the rocker arms. A Pontiac oil pump primer tool (Butler Performance, PN BPI-039P, retail $19.95) is shown on the right. Another choice is an old distributor housing (center). Remove the cam gear and then either use the existing shaft or weld a 7/8-inch nut onto the shaft for a socket. Regardless of the tool you use, the key is to use a heavy-duty 1/2-inch electric drill or have an air compressor that will run an air tool counter-clockwise at a high speed.

With SAE 30-weight oil, Comp Cams break-in oil additive (PN 159, retail $10.76) and an ACDelco filter (PN PF24, retail $5.99) installed, we primed the engine with a Black & Decker electric drill and the Butler tool. The electric drill generated 75 psi of pressure at the gauge (80-psi oil pump) and after running it for a few minutes, we rotated the engine and continued the same two-step cycle until oil flowed out of the tip of each of the rocker arms. Note how the dash had to be unbolted and tipped back out of the way to allow the tool and drill to line up with the oil pump shaft. The time it takes to get oil to all of the rockers will vary based on the type of valve lifters and the power source for the tool.

After priming, we rotated the engine to TDC and installed the distributor with the rotor cap lined up at our previous mark and the vacuum advance pointed at the freeze plug. (The priming tool can be used to properly align the oil pump driveshaft so when it rotates the distributor from left to right (viewed from front of engine) as it drops down into position, the rotor lines up with mark.) Then the distributor hold-down was bolted in.

Next, we installed the spark plugs, valve covers, and HEI distributor cap, and the spark plug wires were routed to their respective cylinders. The distributor connector was plugged in and then the wires that were made to provide power for the distributor (red wire) and to supply a tachometer signal (green wire) were pushed into their respective sockets.