1. Have a good fire extinguisher or two handy during the camshaft break-in.
2. Perform the camshaft break-in operation only with adequate lighting and ventilation conditions.
3. Have a helper available to observe any leaks during the camshaft break-in period.
4. When breaking-in the cylinders and rings, ensure that you leave sufficient safety buffers between yourself and other traffic and pedestrians.
1. Ensure that all open ports in the engine are sealed off with tape and/or plugs. This includes spark plug holes, intake ports, exhaust ports, throttle body mounting flanges, EGR ports, coolant ports, oil system passages, distributor shaft hole, crank snout hole.
2. Do not remove any of the plugs or tape in (1) the above until you are ready to bolt the associated part on to plug the hole (i.e. hoses, spark plugs, harmonic damper, manifold, carburetor, etc.).
3. Never assume that any bolt or clamp you have not tightened yourself is tight. Torque all bolts to manufacturer's recommended values. NEVER leave any bolts finger-tight.
4. Partially fill oil filter(s) with the motor oil you intend to run during the camshaft break-in run. This is to prevent pushing large quantities of air into the oiling system and into the hydraulic lifters (if the engine is so equipped).
Note: If you have already installed the oil filter and have primed the oiling system, do not remove the filter to attempt this step. Doing so will result in an oily mess on the ground!
1. Fill the cooling system completely using a mixture that is between 35% and 50% coolant. Burp all air out of the heater core, block, heads, and radiator. It helps to park the car so that the radiator is above all other engine components. A floor jack will also perform this trick.
2. Use a non-detergent motor oil for initial fire-in and initial run. If a non-detergent motor oil cannot be found, use the oil that you will be planning to use fotr the life of the engine unless you intend to run a synthetic. If this is the case, use a quality milti-viscosity organic oil until 5000 miles have been put on the engine.
3. Remove the valve cover(s) and dribble motor oil onto the rocker arm pivot points (if the engine has rocker arms) or the cam followers and cam lobes (if the engine is a DOHC or SOHC design). Reinstall valve cover(s) and torque to their factory-recommended value.
4. Fill the oil reservoir to its normal "full" level.
5. Burp the cooling system again and re-fill the radiator. Put a little water into the overflow tank (if present), enough to cover the pickup tube from the radiator overflow.
1. Using a suitable tool and a hand drill, rotate the oil pump driveshaft in its normal direction to build oil pressure in the engine. On many engines, this will require removing the distributor from the engine. Engines with dry-sump oiling can be primed by disconnecting the drive belt and using a suitable tool to rotate the pump pulley in the direction of engine rotation. Rotate the oil pump drive until the system is fully pressurized (for approximately 45 seconds after the first major resistance is encountered in driving the oil pump). Some engines (such as the Toyota 20R and 22R family) drive the oil pump directly off of the crankshaft, so these cannot have their oil pumps rotated independently of the crankshaft, so this step will have to be skipped for them.
2. Re-install the distributor (if removed) or oil pump drive belt. Ensure that ignition system is set to a static timing that is close to the initial advance you intend to run. Ensure that the ignition secondary circuits are all wired in the correct firing order. Ensure that the ignition coil is *not* connected or that the ignition is otherwise disabled. Ensure that the battery is connected properly to the starting, charging, and other circuits of the car. Ensure that the air cleaner is properly installed and the filter is clean.
3. Crank the engine using the starter and observe the oil pressure gauge (if installed). Crank the engine for approximately 45 seconds to circulate oil through all of the galleys in the crankshaft, camshaft(s), engine block, cylinder head(s), pushrods (if present), etc.
4. Enable the ignition system by re-connecting it. If the engine is carbureted, prime the carburetor(s). Crank the engine over with the ignition enabled until it fires.
5. Once the engine has fired, immediately bring the engine to a rotational speed of 1800-2200 RPM to ensure that the camshaft(s) and cylinders obtain adequate oiling. Run the engine around this speed range for at least 20 minutes. While it is running, observe the engine for leaks or improper operation and monitor the oil pressure and engine temperature. If anything is wrong, SHUT THE THING DOWN IMMEDIATELY and correct the problem, then finish running-in the cam(s). It is important that the camshaft(s) be run-in for at least 20 minutes prior to applying a load to the engine to ensure that there is no camshaft or lifter scuffing.
7. Shut the engine down and change the oil and filter(s). Changing the oil and filter(s) will remove any debris that has been washed out of the various nooks and crannies in the engine and also reduce oil dilution by the assembly lubricant(s). Allow the engine to cool for at least 6 hours and re-torque the head bolts.
1. Start engine and allow to warm up for approximately 2 minutes.
2. Drive the engine carefully, but do not baby it too much.
3. When driving, bring the engine to speed and get the car into top gear, then vary throttle positions in top gear. Bring the throttle to approximately 80% open and allow the engine to accelerate for a time then back out and allow the car to "compression brake." The high throttle opening places combustion pressure against the rings, forcing them into the cylinder walls and the "coasting" uses cylinder vacuum to draw oil up through the rings to wash away any microscopic shavings created in the power process and prevent cylinder glazing. If the cylinder(s) get glazed prior to the cylinders getting fully broken-in, the engine will need to be re-honed.
4. Continue driving in the manner described in #3 for approximately 500 miles. Shut the engine down after this time and change the oil and filter. Changing the oil and filter(s) at this interval helps to get rid of the last of the assembly lubricant and any of the initial metal shavings that are broken loose out of the engine. Allow the engine to cool for at least 6 hours and re-torque the head bolts.
5. Drive the engine in a moderate, normal fashion for at least another 500 miles. At this point, you can begin to "get on it" if you like. Change the engine oil and filter(s) when the engine has gotten approximately 1500 miles since the last oil change. Change the oil and filter at 3000 mile intervals after that.
6. If you are inclined to pour in some sort of friction modification additive (Slick-50, Prolong, etc.), do not do so until the engine has at least 8000 miles on it. Installing one of these friction modifiers before this time will prevent the rings and camshaft from fully breaking-in.
Copyright 1998 Steven Chin. None of the material presented on this site may be reproduced without the express consent of its'
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