Break in oil in a Roller cam 302

manicmechanic007 said:

Flat tappets do not require break-in oil
No engine requires break-in oil
They (solid lifters) need a little zinc in every oil change

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manicmechanic007 said:

Oil

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Others have already said this - rollers do not need "break-in oil", as the only components that may need help to avoid galling are flat-tappet lifters and cam lobes under high-pressure valve springs. Consider, you want the engine to quickly wear-in to mate the parts on break-in. This means a lubricant, but not the slickest thing you can find. The on-sale oil at your local store in a reasonable weight (10W30-ish for stock-ish rebuild clearances) will do fine for break-in. Realistically, that oil will do fine for the next couple hundred thousand miles as well, and is how they are delivered from the factory.

Break-in is to seat parts together, remove swarf and contaminants, and force wear-in. An example of roller break-in could be a fresh filter (duh), magnetic drain plug, 10W30 dino oil, leak-check and safety check during warmup to temp, at least 10 high-throttle short accel/decel cycles to seat the rings and clean the honing in the first 20 minutes, cool-down drive, dump the oil and filter while warm and clean the magnet.

At this point you can use your good filter and ACEA oil that will be your long-term oil, and change it again at 500 miles to grab any leftovers. 3000-5000 miles thereafter, depending on thermostat rating, 160-180°F at 3k (avoid sludging and acids), and 185°+ at 5k (before additive breakdown). Note things like quick loading of the rings, as they will either find a soft wear pattern at low load break-in, or a full-seat at high-load break-in, but the pattern only "takes" while the honing is fresh and aggressive. There is plenty of evidence out there to show you want a quick, high-load break-in cycle for max sealing, minimum blow-by and oil control. The bearings don't care either way. The OEMs are all moving to a dyno break-in that follows this practice, so the engines are installed ready for their first fresh filter and oil for delivery and maximum engine life.

I mentioned ACEA-rated oil, as that is one way you get the anti-scuffing and anti-wear additives today. Zinc (ZDP) works for flat-tappets, but is obsolete, and the new stuff isn't available as a separate additive (that I have found). I was advised by an oil engineer that one way to get the good stuff (flat-tappets or not) is to look for ACEA ratings, such as A3/B3 or A3/B4. A is for gasoline engine wear additives and B is for scuffing and galling (part of Diesel rating) additives. I use proven good filters and ACEA oil for everything now with any tappets for years, and that's probably overkill for the rollers, but makes me feel good. Catalytic-compatible too. Sing your chants and wave your dolls in the air or whatever if it helps you, but watch the science. Do your thing. Whatever it is, it will probably be fine.

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