Break in procedure


With the right steps during the break-in procedure you can save your engine, your bank account, and your precious time. Our mission at Wolverine Engines is to provide you with the information you need to do this step correctly. Your engine has been carefully remanufactured to precision standards, and will perform properly if certain steps are taken by the mechanic making the installation. Following is a list of causes for a remanufactured engine to fail early in service, and suggested procedures to prevent failure. When a properly remanufactured engine fails to give satisfactory service, it is usually due to: burning piston heads caused by detonation, pre-ignition or “lugging”; piston scuffing or seizing usually caused by overheating or excess fuel; bearing and crankshaft wear caused by underlubrication, dirt or coolant seepage; excessive piston and cylinder wear caused by dirt, ineffective air filtering, coolant seepage or excessively rich, air-fuel ratio. All of which are not covered by warranty. The customer and Wolverine Engines have a mutual interest in this engine. We both want it to perform and give long and satisfactory life


When installing an oil filter, fill it with oil, lube the rubber gasket the surrounds the filter with oil, and then tighten by hand. Consider using a premium brand oil and filter—a cheap filter will not be cheap if it costs you an engine. RPM recommends the use of Wix oil filters and Schaeffer’s oil. Use the proper weight motor oil (straight weight is preferred) with an engine break-in additive (ZDDP or ZINC camshaft additive), especially with flat tappet camshafts. We generally recommend Schaeffers SAE 30 Micron Molly but this can vary from build to build so check with us to verify.


To avoid dry start-up, it is best to prime the oil system with an engine-priming tool or a pre luber, even if the engine has already been ran and has been sitting for a long period of time.

Oil change

Even if you plan on running synthetic oil, you should break a new engine in with a conventional, mineral-type engine oil for the first 5,000 miles. On freshly built engines, you’ll need to change your oil and filter much more frequently. After using a break-in oil, you should change your oil and filter at 500 miles and again at 1,500 miles using the break-in oil. The next oil change will be at 5,000 miles. At this point your engine is fully broke in and you can use the oil of your choice. For marine\ industrial engines the first oil and filter change is at 20 hours. Then again at 40 hours. At this point your engine is fully broke in and you can use the oil of your choice.

Check list before start up

  1. Be sure to prime the oil pump, oil lines and fill the oil filters with oil using an auxiliary pump, operating the internal oil pump with a hand drill, or an external pressure tank connected to the oil pressure gauge or sending unit fitting before starting the engine. It is desirable to fill the crankcase in this manner. If using an air pressure tank be sure it does not run out of oil and blow air through the lines.

  2. Proper air-fuel ratio is vital in today’s engines. Be sure the carburetor or fuel injection system has been remanufactured to manufacturer’s specifications. Manifold and cylinder head surfaces should be checked and in good condition (resurface if necessary). Be sure the cylinder heads and manifolds are torqued and retorqued in proper sequence if required. Air seepage can cause lean air-fuel ratio which causes detonation. Check fuel pump for proper pressure.

  3. Ignition or diesel fuel injection system should be properly serviced or calibrated, and engine timing corrected. Proper valve lash or clearance is very important.

  4. Be sure to use spark plugs of the correct heat range and gap as specified by the engine manufacturer. Check electronic sensors and sending units for proper operation. Vacuum lines must be properly routed and connected to the appropriate fittings to ensure operation of emission control devices and related engine controls.

  5. Check the exhaust thermostat control (commonly called the heat riser) to be certain it is free and operating properly. Check the exhaust gas recirculation valve (EGR valve) for proper operation. Clean the intake manifold to remove deposits from the various passages.

  6. Rebuild or replace the radiator and hose lines to ensure they are free from deposits so that the cooling system can function properly. Restrictions can cause overheating. Thermostats should be checked or replaced with one of the correct temperature. Use the proper pressure cap as specified by the engine manufacturer, and make sure it is properly seated.

  7. Important – replace filter elements. Thoroughly check engine accessories which are to be reused. Clean them internally and externally before installing.

  8. The coolant used should be compatible with aluminum engine components and blended to a mixture of no more than 60% antifreeze and 40% water. We recommend that a good sealer with rust inhibitors be added to the cooling system. This will tend to prevent rust and scale deposits and guard against coolant seepage.

  9. Before releasing the engine for regular service, check the air-fuel ratio. Caution the driver against “lugging.”

  10. If the engine is equipped with an oil cooler make certain this is cleaned or replaced. If your last engine had a failure that resulted in metal in the oil the oil cooler will be full of metal and will cause damage to your new engine if not properly cleaned or replaced.

  11. Set the ignition timing according to the manufacturer. If this is a custom high performance build ask us what to set it to.

    Camshaft break-in

    If your engine is equipped with a roller camshaft you can skip this step. However if you have a flat tappet camshaft great care must be taken to avoid camshaft damage on startup.

    Start engine and run at fast idle, approximately 1500 – 2000 RPM, and check the oil pressure. Roughly set the timing somewhere around 10 – 20 degrees is normally good. Run the engine for 20 minutes even though coolant may rise to operating temperature in a few minutes. Adjust tappets, if required and carburetor. If the coolant should “boil over,” stop engine and allow to cool. Then start again and proceed as above. Note: feel free to stop and start this procedure as need. It does not have to be a consecutive 20 minutes.

    Driving procedures

    1. Before starting the engine for the first time, be sure it has been properly prelubricated.

    2. Never add cold water to the cooling system while the engine is running. The engine should be allowed to run at normal operating temperature.

    3. When required retorque cylinder heads and manifolds to engine manufacturer’s specifications in proper sequence. Readjust tappets if necessary.

    4. Start engine again and make a test run on the road at 30 MPH in “drive” range or select the proper gears for standard transmission. Periodically accelerate to 50 MPH and decelerate rapidly. Repeat this procedure at least 10 times. For a large truck, industrial or marine engine vary rpm between 1500 rpm and about ¾ throttle.
    Do not operate at idle for extended periods.

Do not exceed ¾ throttle for the first 500 miles or 10 hours.

Avoid full throttle acceleration from below 1500 rpm.

Frequently check engine oil level. Add oil as needed. It is normal for oil consumption to be high during the break-in period.

NOTE: Applying loads to the engine for short periods of time causes increased ring pressure against the cylinder walls and helps to seat the rings. This is especially important because you are “breaking-in” the engine with heavy duty oils. The rapid deceleration increases vacuum and gives extra lubrication to the piston and ring assemblies.

Enjoy your engine!

We want to thank you for purchasing your engine at Wolverine Engines ! If you have any questions or need any help along the way please feel free to call. We want to make sure you are completely satisfied with your purchase. If you would like your engine dynoed or dyno tuned we offer special rates for our engine customers. Enjoy and again thank you for your purchase!