Oil

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Late '31
Posts: 93
Joined: Wed Dec 07, 2011 7:43 pm

Oil

Post by Late '31 »

Oil and Your Model A Ford By Pete Cruz
Ever go to the Auto Parts store to buy oil for your Model A and get whatever is “On Sale”? Sure, why not? Given the low maximum RPM your engines run at and the fact that you generally aren’t going long distances, what is the harm right?
In many cases this casual observation may in fact be true, especially if you change the “non-filtered” oil every 500 miles or so.
But what about the Zinc and Phosphorus levels of modern oil? Surely as time has moved on, oil has become better and better - even the cheap stuff…right? Plus, what the heck do Zinc and Phosphorus have to do with my engine oil?
In the past, oil manufacturers used Zinc and Phosphorus as an additive to reduce engine wear. The Zinc referred to in engine oil is actually dialkyldithiophosphate (ZDDP) or zinc di-thiophosphate (ZDTP) commonly used in synthetic oils. Used
together ZDDP/ZDTP is an additive used in oil to improve lubrication. Changes in engine design during the mid ‘50s from solid lifters to hydraulics and the hardening cam surfaces reduced the need for Zinc and Phosphorus in oils. So, since 1994 manufacturers have been phasing out these additives. However what was found is that older engines experience insufficient lubrication, critical at startup when using modern oils with reduced amounts of ZDDP/ZDTP resulting in cam shaft and lifter galling.
So why reduce ZDDP/ZDTP if it is found to reduce engine wear during the critical startup phase of engine operation? Modern oils are expected to last much longer than oil was expected to in 1928 or 1931 for that matter. According to Jim O’Clair with Hemmings Daily, phosphorus build up has been found to create excessive carbon
buildup in engines bores and valve trains. Together ZDDP and ZDTP have also been linked to catalytic converter failures, something Henry and the boys didn’t need think about when designing the Model A.
What the heck does all that mean? Well again, if you aren’t taxing that old engine too heavily, a good quality name brand oil is probably fine. But, if you are taking your car out on long tours and/or don’t change the oil as often as you should, you may want to use an oil with higher levels of Zinc and Phosphorus.
Along with other basic information used in this article, William C. “Bill” Anderson provided this list of oils currently available with the ZDDP/ZDTP levels we’re looking for:
Brad-Penn Oil
Quaker State’s Defy Oil
Classic Car Club Oil
Royal Purple Oil
Joe Gibbs Racing Oil
References:
Anderson, W. C. (2012, June 21). New Oil and Old Cars. Old Cars Weekly News & Marketplace.
O'Clair, J. (2012, October 18). Hemmings Daily. Retrieved from Tech 101: Zinc in oil and it's effects on older engines: http://blog.hemmings.com/index.php/2012/10/18/
tech-101-zinc-in-oil-and-its-effects-on-older-engines/


The Model A Ford uses Society of Automobile Engineers (SAE) 30 ND (non detergent). It is pretty much standard on old cars because they don't have oil filters per se, just screens. If you choose to use a detergent oil, expect issues do to the fact that all the crud in the motor will probably clog the screen.

Old oil had lots of ZDDP (Zinc dialkyldithiophosphates) because it is such a great lubricant. However, it slowly wrecks catalytic converters on new cars, so modern oil has much less. Using modern oil with low ZDDP can slowly damage the engine, so make sure you choose an oil with a decent concentration of ZDDP (say >1500 ppm). Sometimes this isn't possible so you have to buy a third-party additive package which will boost the ZDDP levels.


What you want:
- Straight 40 weight oil (SAE 40)
- Rated no higher than SJ (SC is lower, SM is higher) Note: API intentionally omitted “SI” and “SK” from the sequence.
- Detergent Oil (to get rid of sludge)
- Diesel Oils rated no higher than CI-4 (CJ-4 is higher)
- ZDDP additive (zinc & phosphorous for anti-wear, oils rated higher than SJ or CI-4 do not have enough ZDDP)
- Shell's Rotella oil for diesel engines which has the zinc additive
+++++++ Shell Rotella SAE 30 CF-2, CF $12.58 / 1 Gal
+++++++ SuperTech SAE 30 CF2, CF, SJ $24.72 / 2 Gal
+++++++ STP Oil Treatment 15 FL/OZ $2.74 This has the needed ZDDP that should be used with SA

What you DON’T want:
- SA - NO TESTING is required and it can be applied ONLY to PURE petroleum oil with NOTHING ELSE IN IT.
++++++ Accel SA Non-detergent $2.57 / 1 Qt
- SB - Oil that had some corrosion inhibitors.
- SM or SN - higher than the preferred maximum rating of SJ that is wanted for the Model A
+++++++ Super Tech SAE 30 SN, SM $2.67 / 1 Qt
+++++++ Valvoline SAE 30 SN, SM $?.?? / 1QT
- Multi-Viscosity
- Synthetics
- Non-detergent
- Diesel Oil rated CJ-4 and higher
- Oil without an API rating donut, unless it has all the properties in the above Want List

There is however ONE big advantage to API SA motor oil, it is 100% bio-degradable, so if you have one of those per-1930 cars that burn and leak motor oil quicker than you can pour it in, you do have a good environmental excuse for using it.

In 2003 California finally did someting about the API SA Motor Oil, not because of the damage it may do to consumer's vehicles in California, but because those damaged vehicle engines may pollute the Air.

Reprint article from: LUBE REPORT July 9, 2003 - http://www.synlube.com/LUBEREPORT_CA_SA_SB.htm


American Petroleum Institute (API) Oil Ratings - http://www.apicj-4.org/EngineOilGuide2006.pdf

The Society of Automotive Engineers (SAE) has established a numerical code system for grading motor oils according to their viscosity characteristics. SAE viscosity gradings include the following, from low to high viscosity: 0, 5, 10, 15, 20, 25, 30, 40, 50 or 60. The numbers 0, 5, 10, 15 and 25 are suffixed with the letter W, designating their "winter" (not "weight") or cold-start viscosity, at lower temperature. The number 20 comes with or without a W, depending on whether it is being used to denote a cold or hot viscosity grade.

Single-grade engine oil, as defined by SAE, has established eleven viscosity grades, of which six are considered Winter-grades and given a W designation. The 11 viscosity grades are 0W, 5W, 10W, 15W, 20W, 25W, 20, 30, 40, 50, and 60. These numbers are often referred to as the 'weight' of a motor oil; and single-grade motor oils are often called "straight-weight" oils.

Another great article about oils and ZDDP.
http://www.fordbarn.com/forum/showthrea ... post409744
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