440_Stroker

My new 440 is on its 3rd oil change with 15-40 Rotella Diesel oil, conventional in the white jug, not synthetic.

I will switch to synthetic in a few more changes.

Polyalphaolefin

Given that it's a fresh motor that hasn't been run or broken-in, it will greatly benefit you to use a dedicated break-in oil such as Driven BR30 or Amsoil Break-In SAE 30. These oils are specifically formulated for establishing an initial protective anti-wear tribofilm on fresh parts. They contain a very high concentration of highly reactive, short-chained, secondary alkyl ZDDP (2400-3000 ppm Zn and P) which can breakdown and start protecting even at room temperature. These oils also contain no friction modifiers, viscosity modifiers, pour point depressants, neutral detergents, or any other additives that may interfere with ZDDP's reactivity or it's ability to apply that initial tribofilm. This is why oils like Rotella and VR1 aren't ideal break-in oils as they contain the wrong type of ZDDP, don't have high enough concentration (not by half), and contain all of the additives above which can hinder the initial tribofilm establishment regardless of the ZDDP concentration. Break-in oils are more about what they don't contain than what they do.

An ideal break-in procedure will include heat cycles with varying rpm and load. I like to start it up and go to 2000 rpm for 5 minutes (20 minutes with a flat tappet cam). Shut it off, and let it cool all the way down. Then start it up again, and start varying load and rpm. Go out in 2nd gear and hit it WOT from 2000-4000 rpm and then coast in gear back down to 2000 rpm. Repeat 20-30 times. You can be tuning during this period as well. Then shut it off and let it cool all the way down again. Then I change the filter only, not the oil. You can change the oil if you want with fresh break-in oil, but it's not really necessary. I then go 100-250 miles and then change the break-in oil and filter for the oil and filter of choice. It's fine to use synthetic past that point. If the break-in is done properly, there's no reason to keep using conventional past that point. Remember that during the break-in, you want to keep the engine under a load and the rpm up. You don't want to let it idle.

The appropriate viscosity for the engine depends on 3 main factors: the operating oil temperature, the rod and main bearing clearances, and the load placed on those bearings.

Zinc is a short term referring to zinc dialkyldithiophosphate (ZDDP), a trimolecular ester comprised of zinc, phosphorus, sulfur, and various alkyl groups and used widely as both an anti-wear and anti-oxidant additive. ZDDP is not a single additive, but rather a family of additives. There's ~200 different ZDDPs out there that all behave a little differently. The type found in modern API CJ-4 and CK-4 HDEOs (like Rotella T series) is a less reactive primary alkyl ZDDP designed more for anti-oxidant use than anti-wear. It's also less damaging to DPFs. Modern API SN, SN Plus, and SP PCMOs use a 70/30 secondary/primary blended alkyl ZDDP for better stop and start protection and higher rpm use seen in gas engines. Break-in oils use a highly reactive secondary alkyl ZDDP for initial tribofilm establishment and dedicated racing oils (Driven XP series, HPL BAS) use a similar secondary alkyl ZDDP but with higher thermal stability. The type of ZDDP used in aftermarket oil supplements is largely unknown and can vary depending whatever type is cheapest at the time.

Pretty much this. Splitting hairs, but zinc isn't actually limited by API. It's the phosphorus that's limited to 600-800 ppm in modern API oils. Zinc is just a neat metal carrier for the ZDDP molecule and doesn't actually serve any anti-wear function. The phosphorus and sulfur carries the anti-wear load. You could replace zinc with tungsten (WDDP) or titanium (TiDDP) and the molecule would function the same. Zinc is just dirt cheap and readily available so it's what gets used. The poisoning of cats is a dramatized issue. It takes a lot of oil consumption out of the exhaust to actually damage the cats (like a quart every 500 miles kind of consumption), now the cats will only last 400k miles instead of 500k. It doesn't really matter when most cars rust in a junkyard with <300k miles on them anyway.

You have so many varying opinions because oil is not well understood... which is sad considering it's the blood of the engine.. and even sadder that a lot of people think they know but really don't. A lot of the popular hot rodding magazines and blogs don't help matters as they often regurgitate the same myths and misconceptions with little actual fact checking. Then you have Youtube channels, regardless of the best intentions, create even more myths and confusion such as Project Farm. His oil and supplement videos have caused me a lot of headaches over the years. Bless the man, he's genuinely a nice guy, but I hate his videos. I recently did a study on increasing iron levels in a 4-cylinder dirt track engine. Running an oil sample under analytical ferrography determined that the iron was coming rust, not abrasive wear. Further FTIR analysis showed a fairly high amount of chlorine in the oil sample. The chlorine came from chlorinated paraffins, the main ingredient in the oil supplement Motorkote, which the owner had started using after seeing the results of it in a Project Farm video. Yes, CPs will reduce friction and scuffing wear, but are highly corrosive which is why we don't use them in engine oils. The engine was torn down and found spalling on the cam, cylinder walls, crankshaft, and block from corrosion.

Penrite is a good oil, but note that more ZDDP isn't always better. ZDDP is a bit of a double-edged sword. It's a trimolecular ester that's acidic in nature so as the concentration increases, so does the oil's acidity. Outside of initial break-in, there's no application on Earth that needs more than 1400 ppm. Past that, you just increase acidity without any additional wear protection benefit. Penrite uses a higher concentration than that solely because of marketing to the "more must be better" crowd which is the only thing I don't like about them. Lucas oil is the biggest perpetrator of that. They know their ZDDP concentration is well into corrosive territory, but they don't care because it sales to people who don't know any better.

No doubt that Amsoil makes good oils but don't take those PF videos as gospel. None of his tests actually test the parameters of engine oils. The scar test is an old abandoned rig that was designed to determine the scuffing resistance of greases. Putting an engine oil in it is like asking a Prius to tow a school bus. It's way outside of what the oil was formulated for. If you were to go by the original standards for that scar test, every oil he has run in that rig has failed miserably (as expected), including Amsoil. The results are also highly unrepeatable, making any comparison of two oils no more valuable than a coin toss, which is why the rig was abandoned by SAE decades ago to begin with. Even the pour test is useless because cold start performance isn't about pouring but rather is about pumpability. That's why cold start simulation tests are measured in dynamic viscosity (under pressure) using a mini-rotar viscometer (MRV). Two oils could pour at different rates, but still pump at the same rate.

Che70velle

iTrader: (6)

And there you have it folks....enough guessing and he said-she said stuff. Just the facts from a professional in the industry. Thanks again Poly for clearing up yet another oil thread. Merry Christmas folks!