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Engine Break-in Instructions

Pavel’s Racing Engines recommends the following engine break-in instructions to all of our engine customers. The following procedure is a compilation of information collected over the years from very reputable sources such a TRD Formula Atlantic, VW SuperVee, and World Champion snowmobile engine builders. We have had zero engine failures due to using this engine break-in procedure.

Engine Break-in Procedure

(Some points may not apply to your engine)

To ensure long life and reliability you must properly break in your freshly assembled engine. Most critical engine break-in and piston ring seating occurs within the first twenty miles of driving. Proper break in ensures higher compression, less oil consumption, less blow-by, and most importantly longer engine life.

For high performance motors, fill with good grade mineral oil. NEVER USE SYNTHETIC OIL FOR ENGINE BREAK-IN!

Composite fiber/graphite head gasket need to be re-torqued after heat cycling the engine. Multi layer steel head gaskets do not require to be re-torqued.

Valve lash needs to be checked and/or adjusted on solid lifter motors only. Hydraulic lifter engines are exempt from this step. Make sure hydraulic lifters were bled properly prior to engine assembly. Certain applications allow for hydraulic lifter bleeding with the engine running, while others do not allow for such procedure at all. Reference manufacturers service manual for specific information pertinent to your application. Adjustment on bucket style solid lifter systems is not necessary in most cases. Adjustable rocker arm lifter system commonly found on Honda engines needs to be checked and/or adjusted after initial engine run-in.

Engine break-in oils such as Valvoline or Brad Penn should be used when possible. Use straight 30W engine break-in engine oil. When break-in oil is not available fill the engine with good grade 20W-50 mineral based oil.

Always use new spark plugs in your engine.

Fill the oil filter with oil before installing it. Remove the spark plugs and crank the engine until proper oil pressure shows on the gauge. Re-install the spark plugs. Now you are ready to start the engine.

Start the engine and check for leaks. Make sure the vehicle is completely operable for its first run. Warm up the engine completely. After 15 minutes stop the engine, check the valve lash and re-torque the head bolts. Drain the oil and change the filter. Re-fill the engine with 20W-50 mineral based oil.

You will be driving the engine hard to ensure proper ring seating. It is best to perform engine break-in on the dyno or a race track. Do not attempt to race the engine on the street. This puts yourself and others around you in danger.

Street break-in: Warm up the engine completely. Drive at slow vehicle speeds with a lot of throttle opening in 2-4 gears at high engine RPM. Don’t lug the engine because that is worse for the motor than over revving it. Low engine RPM and high throttle opening is bad for your engine. Do so in burst of acceleration and deceleration. Do not run the engine at a constant engine speed. This can cause piston ring glazing.

Racetrack break-in: Warm up the engine completely. Do one easy lap to warm up the tires. Go back to the pit and check for leaks or any problems. If everything checks out, take a normal 15 minute practice session and check water temperature frequently. The racetrack is a perfect place to break in the engine. The combination of acceleration and deceleration is exactly what you need for optimal piston ring seal.

It may be useful to cut open used filters and inspect for metal particles and shavings after initial engine break-in run.

After 500 miles change the oil and filter again. You can now use synthetic oil if you want to. Use 20W-50 oil and change it every 3,000 miles. Your engine is now broken in.

Any questions please contact us for technical assistance. Thank you for your business!