Tech Articles

Engine Break-in Procedures

Engine Break in Recommendations

If you have received an engine shipped from us, it will have had oil in it and has been brought up to running pressure by turning the oil pump to check that oil is getting to all of the passages.
The oil has been drained before shipping. Bringing the oil pressure up by manually turning the
oil pump, before installing the distributor is recommended before startup, especially if the engine has been sitting for an extended period of time.

As most oils have now reduced the levels of  the crucial additives necessary for flat tappet lubrication ( Phosphorus and Zinc ), we recommend that you use a petroleum oil for break -in of the cam that is high in these additives and/or use a cam break-in additive. Do not use an oil for these engines, or any flat tappet/lifter engine that has an SM or SN designation without further checking on the Phosphorous and Zinc levels as it  usually indicates that the amount of these additives have been reduced. Mobil 1 15W-50 may be an exception.  See their new chart for 2018 for details:

Set the timing as close as possible when installing the distributor. It is important the engine start up right away, so you are not turning it over at slow speed on the starter for very long.
In breaking in the cam, do not run the engine under 2000 rpm for the first 20 minutes. It can be run without any load, or with a light load. Be extremely carelfull that the engine does not overheat, which can be caused by not having enough timing advance. 

Re-torque the head while the engine is  still warm, after 20 - 30 minutes of running. Tighten the bolts/stud nuts  following the recommended pattern in the Volvo manual.  Back off each head bolt or stud nut 1/4 turn and then bring up to recommended torque - usually 75 lbs.   Then recheck the valve lash. For most our engines valve lash clearance should be .016 - 018 as stock. We recommend using the nines method - open one valve up all the way and adjust the one that when added to the open one =s 9. ( #1 open, adjust # 8 - #2 open, adjust # 7)
In initial driving keep the loads on the engine light and gradually work up to harder and harder accelerations, keeping them brief at first and then longer. Try to avoid highway driving where the engine will have to stay within a narrow rpm range for long periods. Back roads are the best place where you can control your pace, accelerate back off, accelerate again.

After 500 miles the engine is considered broken in. Change the oil and filter.
I strongly recommenden the use of a full synthetic oil after break in.  Our previous recommendation was to use Mobil 1 15W-50 for the summer and 10W-30 High Mileage for the winter in areas with comparatively cold winters. This recommendation was based on both of these oils being higher in the additives, taken out of other oils, which lubricate flat tappet lifters and cams. According to the most recent specifications from from Mobil, the 10W-30 oil no longer is as hight in additives as is the 15W-50.  See their chart for details.