Break-In Oil Analysis

26 Oils Tested

These oils represent many different brands of break-in oil and several oils commonly used for break-in. We are not endorsing any specific brand of oil, but we will provide guidance to make sense of these results (based on our years of experience). Just to be clear, we are not only talking about flat tappet cam break-in here. We are talking about piston ring break-in (ring seating) in both roller cam and flat tappet engines. It is also worth stating, piston ring break-in is far more complex than just the oil.

With all of that said, the lowest levels of blow-by and highest levels of vacuum during break-in (indicators of ring sealing efficiency) have come from the following chemical characteristics →

01

Non-synthetic oil. Without getting too deep into chemistry, too low of a coefficient of friction impedes the break-in process.

02

Low detergent oil. The “old school” method of Straight 30 Non-Detergent had some solid chemistry behind it. High levels of detergent additives do slow down the break-in process. However, non-detergent oils at the local part store are likely not to contain any ZDDP or other additives for that matter.

03

ZDDP fortified. Speaking of everyone’s favorite anti-wear additive, ZDDP is necessary to prevent scuffing and welding, so a good break-in oil will have an ample supply of ZDDP. However, beware the temptation of “more is better”. Too much ZDDP can get you into trouble. Balance is the key. Think about oil chemistry like Goldilocks and the Three Bears - Not Too Much, Not Too Little, but Just Right.

04

No Molybdenum. Again, without getting too deep into chemistry, too low of a coefficient of friction impedes the break-in process, and Molybdenum is a fabulous friction reducer. We hope this information is helpful. We are not saying any of these products are bad. We are simply sharing our experiences of what we have seen works the best, especially with advanced piston ring designs and coatings that do reduce friction and increase engine efficiency.