So what yall are saying is don’t use a synthetic oil and use one with enough zddp in it (around 1400-1600)
What I am saying is that if you don’t have roller rockers and other new tech engine parts, use an oil with 1400-1600 ppm. The cheapest oil is WalMart brand, Motorcraft, or maybe Shell Rotella T, 15W40 CJ-4 rated oils. There are full synthetics and synthetic blends out there (Valvoline VR1, boutique oils like Hemmings Motor News Motor Oil) that have that much ZDDP, but they will cost 3-5 times what the cheaper ones do, for no real benefit. It’s your money, spend as you like.
It’s the cam, not the rockers WRT needing ZDDP.
Thanks to everyone for all the help! I was on a previous forum with my last vehicle and never received this much input.
Yes, and I should have been more precise, a roller cam system. Actually, many rockers in those also have roller tips, and the CJ-4 oil is for sliding friction and wear protection, not rolling.
So is the valvoline vr1 20 - 50 OK or is it too high of a viscosity. I live in San Antonio Texas it doesn’t get real cold here
That should work fine in San Antonio. The 20 weight is good for cold starts down to about 20-25 degrees or so, and the 50 weight works well for hi-temp conditions above 100 ambient and engine temps above 220 or so.
Thanks
Thanks Mike, this is some really good stuff. Does any of this effect rear axle lube or what we put into a manual transmission? I am thinking not since it would not effect the catalytic converter, but thought I would ask if you had heard any new recommendations for those oils.
I have not heard of any discussions around those lubes, guess it is not as much fun as oil, since there are about ten gazillion varieties out there!
Amsoil Z-Rod is designed for older motors. A quote from the webpage:
AMSOIL Z-ROD™ Synthetic Motor Oil is specially engineered for classic and high-performance vehicles. It features a high-zinc formulation to prevent wear on flat-tappet camshafts and other critical engine components, along with a proprietary blend of rust and corrosion inhibitors for added protection during long-term storage. Z-ROD Synthetic Motor Oil is designed to perform on the street and protect during storage.
All my vehicles run Amsoil. Old to new. Don’t be afraid to go synthetic. I switched my 1992 F-150 to synthetic with 250k miles on the clock and it ran better than ever without leaking.
That is a good oil, and it is almost $10/quart. On the other hand, you can get a 5 quart jug of Motorcraft 15W40 CJ-4 oil for about $20 in many places. The ZDDP contents are identical, but it is your money, spend it as you please.
I was thinking that I use to use synthetic in my 1980 international scout and don’t remember any leaks showing up. But it was a new crate engine though.
Can’t beat the wear protection if synthetic at start up.
Yes, we have debated that for years, and no consensus seems to emerge or scientific evidence:
It wasn’t about it staying at the top of the engine, it’s the fact that synthetic has better cold flow properties than conventional and gets to the top of the engine faster. Remember those prolong ads where they took a tractor and ran it with no oil. Hah.
Yes, there is some truth to that, at the same weights. But if you use a lower vis dino oil, the same flow properties exist, say a 15W40 dino vs. a 20W40 synthetic, about the same. One argument was that since a high percentage of wear occurs at start-up then a used oil analysis between synthetic and dino would show this scientifically. The problem is that all the used oil tests (micro-analysis of amounts of metal compounds in the oil, indicating wear) I have seen in identical vehicles and standard driving tests have shown no statistically significant difference, all within 1 SD variances. So I am not convinced Synthetics offer anything significantly different worth paying 4 times as much for, IMO.
Synthetics have better stability at high temperatures, have longer drain intervals, less burn off. If you become an Amsoil dealer you can actually save quite a bit of money on their products. For those that store their cars, synthetic is good for up to a year rather than the 3 months or 3000 miles.
Having physically torn down multiple engines, engines that ran syn had significantly more cross hatching left on the cylinder walls and far less camshaft wear. I was not a synthetic believer myself until I saw the evidence with my own two eyes.
But if you are one of those that is crazy about changing your oil, you probably won’t see those benefits.
I agree about the hi-temps, and heavy duty track/race apps, they are significantly better than dino. A full synthetic is “created” not refined, so much, much fewer impurities and the hydrocarbon compounds are more consistent in structure can to can. That’s why they cost so much. I run only Mobil 1 in my 2012 ZR1 and 2013 GT350. Hi-performance supercharged engines that run hot all the time, and are full of titanium, aluminum, and other exotic alloys demand it, not a dino oil which is fine for cast iron and forged iron, but not other metals. But, in my old muscle cars, old school engines which I do not race and temps are low to moderate most all the time, and they rarely get more than 1-2K miles a year, I use the CJ-4 oil. I change once a year, whether they need it or not…. 
I prefer to put the very expensive oil where it earns its’ high price, and leave the old engines to what they need most.
If you run Mobil you might want to switch to the extended drain version as the regular version is a class iii and not class iv base stock. There’s an Amsoil warehouse here in Vegas so it is probably a lot more convenient for me to get it.