Official "What oil / additives should I use" topic

[Wildthings]

[Bruce Amacker]

[Guack007]

Is everyone referring to Valvoline 10W30 VR1 conventional (silver bottle) or synthetic (black)?

Is this correct:

Valvoline VR1 Racing SAE 10W-30 High Performance High Zinc Motor Oil 1 QT, Case of 6 https://a.co/d/h8GHAXc

[static]

I have been purchasing the Valvoline VR1 (with zinc!) for my aircooled engine, but always have grumbled at the price per quart.

Castrol GTX is now available (with zinc!) for a few bucks less a quart, but Walmart has an exclusive deal to sell it retail. Five quart bottles only, AFAIK.

Just a data point.

[miniT2]

Anyone, other than myself, running Mobil 1 V-Twin oil? Its got plenty of zinc and phosphorus...

[vamram]

[drewnashty]

[udidwht]

Over the years there has been an overabundance of engine oil myths. Here are some facts you may want to pass along to customers to help debunk the fiction behind these myths.

The Starburst Oil Myth -- The latest myth promoted by the antique and collector car press says that new Starburst/ API SM engine oils (called Starburst for the shape of the symbol on the container) are bad for older engines because the amount of anti-wear additive in them has been reduced. The anti-wear additive being discussed is zinc dithiophosphate (ZDP).

Before debunking this myth, we need to look at the history of ZDP usage. For over 60 years, ZDP has been used as an additive in engine oils to provide wear protection and oxidation stability.

ZDP was first added to engine oil to control copper/lead bearing corrosion. Oils with a phosphorus level in the 0.03% range passed a corrosion test introduced in 1942.

In the mid-1950s, when the use of high-lift camshafts increased the potential for scuffing and wear, the phosphorus level contributed by ZDP was increased to the 0.08% range.

In addition, the industry developed a battery of oil tests (called sequences), two of which were valve-train scuffing and wear tests.

A higher level of ZDP was good for flat-tappet valve-train scuffing and wear, but it turned out that more was not better. Although break-in scuffing was reduced by using more phosphorus, longer-term wear increased when phosphorus rose above 0.14%. And, at about 0.20% phosphorus, the ZDP started attacking the grain boundaries in the iron, resulting in camshaft spalling.

By the 1970s, increased antioxidancy was needed to protect the oil in high-load engines, which otherwise could thicken to a point where the engine could no longer pump it. Because ZDP was an inexpensive and effective antioxidant, it was used to place the phosphorus level in the 0.10% range.

However, phosphorus is a poison for exhaust catalysts. So, ZDP levels have been reduced over the last 10-15 years. It's now down to a maximum of 0.08% for Starburst oils. This was supported by the introduction of modern ashless antioxidants that contain no phosphorus.

Enough history. Let's get back to the myth that Starburst oils are no good for older engines. The argument put forth is that while these oils work perfectly well in modern, gasoline engines equipped with roller camshafts, they will cause catastrophic wear in older engines equipped with flat-tappet camshafts.

The facts say otherwise.

Backward compatibility was of great importance when the Starburst oil standards were developed by a group of experts from the OEMs, oil companies, and oil additive companies. In addition, multiple oil and additive companies ran no-harm tests on older engines with the new oils; and no problems were uncovered.

The new Starburst specification contains two valve-train wear tests. All Starburst oil formulations must pass these two tests.

- Sequence IVA tests for camshaft scuffing and wear using a single overhead camshaft engine with slider finger (not roller) followers.

- Sequence IIIG evaluates cam and lifter wear using a V6 engine with a flat-tappet system, similar to those used in the 1980s.
Those who hold onto the myth are ignoring the fact that the new Starburst oils contain about the same percentage of ZDP as the oils that solved the camshaft scuffing and wear issues back in the 1950s. (True, they do contain less ZDP than the oils that solved the oil thickening issues in the 1960s, but that's because they now contain high levels of ashless antioxidants not commercially available in the 1960s.)

Despite the pains taken in developing special flat-tappet camshaft wear tests that these new oils must pass and the fact that the ZDP level of these new oils is comparable to the level found necessary to protect flat-tappet camshafts in the past, there will still be those who want to believe the myth that new oils will wear out older engines.

Like other myths before it, history teaches us that it will probably take 60 or 70 years for this one to die also.

[Bruce Amacker]

[Wildthings]

There is a lot more than "flat tappets" that affect cam wear. The added weight of heavy lifters, push rods, and rocker arms means the use of heavier valve springs this of course means higher contact pressures between the cam and the lifters. Ratio rockers have an effect here as well. Type 4 engines have a notorious wear problem as the cam and lifter run up the miles as well. Not only does each lobe on the cam operate two valves on VW aircooled engine, on a Type 4 the lifters are oddly offset on the lobes causing proportionally more wear in the center of the lifters making them wear concave at lower mileages, and once they become concave the wear to the lifters and camshaft accelerates. The difference in wear rate between a Type 4 with hydraulic lifters and a Waterboxer running the exact same lifters is extreme and even when comparing a Type 4 with solid lifters to a Waterboxer with hydraulics there is a big difference in the wear rate.

That said there have been big improvements in oils since the low ZDDP oils came into use with the SM standard 20'ish years ago. Today there are other antiwear additives added to the oils besides ZDDP and the ZDDP that is used does not degrade as readily meaning less is needed to get the job done.

At this point I typically run extended oil changes using either 5w40 Mobil 1 Turbo Diesel Oil or 5w40 Mobile 1 European Car Formula Oil. If you don't want to pay the price for synthetics while getting most of the benefits run a straight 30wt oil, as today's straight weight oils are not your grandfathers oils, but a more highly refined replacement that still doesn't depend on viscosity modifiers.

[BigGar]

After reading much of 540 RAT's oil blog I'm going to get some Amsoil 10w50 Dirt Motorcycle Oil or some Harley Davidson 20w50 Screamin' Eagle SYN3.
Ultra high thermal breakdown and excellent wear protection.

I feel like thermal breakdown temperature being as high as possible alongside extremely high wear protection is hard to beat.
I just picked up a little Manx clone with a fairly fresh 2180.

I do need to put a clutch in it soon so I'm just getting my air cooled VW feet wet again after nearly 50 years of not playing with dune buggies.

I live just north of San Diego and most of it's use will be around town here or running the beach and trails of northern Baja.

Rarely any use at temps under 50 but quite possibly a lot of hard running in warm weather between 75 to 95. That, and sitting in SoCal traffic.

[Cubey]

The '64 baja I got several months ago, with a '65 40HP, is an oil burner for sure. The dipstick level drops pretty quickly driving it around the small amount I do currently. It had a very sludgy oil strainer when I changed the oil, so it was highly neglected.

It has "ok" compression across all 4cyls. Not great but it's not totally done for yet either. (around 100-110)

It's currently running 15w40 diesel oil, because I always have some around for my old '85 diesel motorhome. (brand always varies)

Thinking I might add some STP to the bug to slow the oil burning. The bottle says it adds ZDDP so that's in addition to the zinc in the diesel oil.

Yeah Castrol GTX classic 20w50 isn't too expensive online for 5qts, but I'm an RV nomad, so I can't always get mail easily. Diesel oil + STP can be bought most anywhere. Bottle says full bottle for 4-5qts, so half a bottle (7.5oz is half) should be plenty for the bug. And only add it once per oil change, only oil after that.

[Wildthings]

[Cubey]

[Cubey]

Huh, wow. Supposedly Delvac has only 879ppm of zinc:
http://pqiadata.org/Mobil_Delvac_15W40_732018.html

Compared to 1,127 for O'Reilly:
http://pqiadata.org/OReilly_15W40.html

Other mainstream/easy to get brands all seem to have over 1,000 except for Delvac and Delo.

[Wildthings]

Since fewer diesel oils are now carrying an "S" rating along with a "C" rating, I found this article to be worth the read.

https://www.motortrend.com/how-to/diesel-oil-in-gasoline-engine/

[Cubey]

[Wildthings]

[vwracerdave]

[Cubey]