Big2Bird

http://www.nonlintec.com/sprite/oil_myths.pdf

Drawmain

63mako

The new Starburst specification contains two valve-train wear tests. All Starburst oil
formulations must pass these two tests.
1 Sequence IVA tests for camshaft scuffing and wear using a single overhead camshaft
engine with slider finger (not roller) followers.
2 Sequence IIIG evaluates cam and lifter wear using a V6 engine with a flat-tappet system,
similar to those used in the 1980s.

These are the tests used to determine backward compatability. The spring pressures in the second test are in the #200 open range with lifts under .400 and they are testing new oils with a full battery of antiwear additives. The camshafts in the 50's had very slow ramps and low spring pressures also and lift under .400. Modern flat tappet and performance OEM cams have faster ramps, stronger springs and higher lift than any tested and require more protective extreme pressure additives than those low lift, low spring pressure cams referenced. This was a problem for GM in the 60's and 70's even with .1 and higher ZDDP in the oil and much lower detergent levels than we have today and they came up with a phosphorous coating for their factory cams to reduce warrantee issues related to low ZDDP levels and no factory break in. The automakers were the ones pushing for ZDDP reductions in the 90's and early 2000's because the EPA was requiring Catalytic Convertors to last 100,000 miles and the OEM no longer used flat tappet cams. Mandatory ZDDP reduction was the easy out for the manufacturers as they no longer needed to concern themselves with warrantee coverage on flat tappet cammed engines so take their conclusions with a grain of salt. They never tested even an L48 type loading in the Sequence IIIG testing for good reason.

63mako

Here are the ASTM test procedures. The test engine in the ASTM testing has roller lifters. The Duration @ .050 is 182/192 and lobe lift numbers are .258/.258.
Is this a valid test to assure SM rated oil will protect your flat tappet cam long term? Testing never goes above 3600 RPM, steady load, steady rpm with a super mild, low spring pressure roller cam.
http://www.swri.org/4org/d08/GasTest...st/default.htm

Sequence IIIG Test Equipment and Procedure
The Sequence IIIG test uses a 1996/1997 231 CID (3,800 cc) Series II General Motors V-6 fuel-injected gasoline engine.



Using unleaded gasoline, the engine runs a 10-minute initial oil-leveling procedure followed by a 15-minute slow ramp up to speed and load conditions. The engine then operates at 125 bhp, 3,600 rpm, and 150 °C oil temperature for 100 hours, interrupted at 20-hour intervals for oil level checks.


Sequence IIIG Test Results
At test end:

All six pistons are inspected for deposits and varnish.

Cam lobes and lifters are measured for wear.

Kinematic viscosity increase (percent increase) at 40°C is compared to a new oil baseline every 20 hours.

Wear metals Cu, Pb, and Fe, are evaluated.

Sequence IIIG Pass/Fail Criteria
PARAMETER
PASS LIMIT

Viscosity increase
150%

Weighted piston deposits
3.5 minimum

Average cam-plus-lifter wear
60 μm maximum

Stuck rings
None

Hot oil consumption interpretability
4.65 L, maximum

Big2Bird

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.)

Bob Olree. GM Powertrain group

Big2Bird

I just equate alot of this to Tetra Ethy Lead.
Developed in WWII as an OCTANE enhancer, the big oil companies BS'd everyone about valve lubrication.
When they took it BACK out, as in previous to 1942, nothing happened.
There are not reams of catastrophic valve failures around the world.

Big2Bird

Mobil one also says, no problemo.

http://www.mobiloil.com/USA-English/...ollection.aspx

63mako

Your missing the point. Cars in the 50's had really slow ramps and really weak springs and really low lift and needed 800 PPM minimum ZDDP to live. A 1950's, early 60's engine with 100,000 miles on it was worn out. By the mid 70's ZDDP levels were not 1000 ppm but 1400. Lift, spring pressures and ramp rates were higher. Many of those engines ran well over 100,000 with no issues. If you want to use oil with under 800 PPM ZDDP in your flat tappet engine go ahead but my question to you is why would you when there are plenty of oils available with ZDDP levels recommended by all flat tappet cam manufacturers and similar to the levels available when your car was designed?

63mako

Yes they do. No problemo with 1200 PPM. Read it, you linked it. Every answer references higher ZDDP levels are recommended for flat tappet cams.

63mako

Talked to a friend over the weekend that is a member of the Society of Tribologists and Lubrication Engineers. He started anyalizing oil 15 years ago and now works for Compass Instruments, Service and support, Compass Instruments product lines. Perform routine maintenance, calibration, repairs, and equipment evaluation. Also provides technical assistance and training. Travels all over the country and works with most of the major oil companies. He is a lubrication engineer and has been in the business for 15 years. His previous job was software designer for Falex Corperation. He is one of the most intelligent guys I know. His thought on the Sequence IIIG testing was that it was done as a compromise between the EPA, Auto manufacturers and oil companies to satisfy them all when lower ZDDP was mandated. There was no initiative by any of these entities to test high rpm use or aftermaket applications. Their objective was to develop a test that would justify a backward compatability rating with lower EP additives. The one point he stressed was the lifter foot loading will increase about 2 1/2 times from 3600 RPM to 6000 RPM. He also said in their testing Amsoil was far and away the very best base stock and additive package available. Here is his Professional link. http://www.linkedin.com/pub/nathan-pekoc/5/3a6/743