oil light? Options

[bd1308]

QUOTE

"W" means winter. In winter weather the 0W oil will flow like a 0W oil, and the 5W will flow like a 5W oil and a 10W will flow like a 10W oil just until the engine warms up.

its late here, is this to prove i got the original Q wrong or what?

b

[Howard]

Right. Just teasing you a bit. (IMG:http://www.914world.com/bbs2/html/emoticons/poke.gif) In engineering gibberish:
SAE 30 is SAE 30 no matter what the "W" prefix number is: 0W, 5W or 10W. This viscosity in centistokes (cSt) @ 100 degrees C is with the minimum of 9.3 cSt and a maximum of 12.5 cSt.

SAE defines 'normal' operating temperature in this case to be 100c or 212f. In order to have the SAE rating of 30, the oil must maintain that viscosity at that temp. The '10w' out front just means the viscosity at freezing is SAE 10. This allows the engine to better circulate lubricant at lower temps.

So 50 doesn't thin to 30. While 20w50 won't hurt, I still believe the 914 will benefit from lower viscosity oil. The benefits are cooler operating temps and less drag on the reciprocating parts. Just my 2 cents...

[Bleyseng]

I try to maintain good hot oil pressure so I use the 20w50. The 20w is like the 30w when cold just is thicker when Hot.

copied this from a site...was looking for a site that had how much better 20w50 protected via viscosity....

"Multi-weight oils (such as 10W-30) are a new invention made possible by adding polymers to oil. The polymers allow the oil to have different weights at different temperatures. The first number indicates the viscosity of the oil at a cold temperature, while the second number indicates the viscosity at operating temperature. This page from the Sci.Electronics.Repair FAQ offers the following very interesting description of how the polymers work:

At cold temperatures, the polymers are coiled up and allow the oil to flow as their low numbers indicate. As the oil warms up, the polymers begin to unwind into long chains that prevent the oil from thinning as much as it normally would. The result is that at 100 degrees C, the oil has thinned only as much as the higher viscosity number indicates. Another way of looking at multi-vis oils is to think of a 20W-50 as a 20 weight oil that will not thin more than a 50 weight would when hot."



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[eg914]

There was an article in Excellence last year or the year before regarding oil. Porsche recommends 20w-50 for all air cooled engines. Its what I use in my 914 and my son's 73 bug.

[Brando]

Use 10W30 oil, synthetic if you're made of money, dino if you're a CSOB like the rest of us.

Unless you're in the arctic (Canada) you should be fine with 10W30.

[dlo914]

QUOTE (Howard @ Jan 15 2006, 08:15 PM)

OK, quick test. With 20w50 oil, what does the 'w' stand for? Think 0 and 100 Celsius (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

W=winter...not weight as some thing (IMG:http://www.914world.com/bbs2/html/emoticons/dry.gif)

[dlo914]

QUOTE (Howard @ Jan 15 2006, 08:15 PM)

OK, quick test. With 20w50 oil, what does the 'w' stand for? Think 0 and 100 Celsius (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

W=winter...not weight as some thing (IMG:http://www.914world.com/bbs2/html/emoticons/dry.gif)

[Howard]

Would really like to hear from the experts here. Jake? Cap'n? What's the call?

[bd1308]

i dont think i messed up. I think we were saying the same thing Howie....

[SLITS]

Jeeeezzzzes....google it yourself..........


Most people are familiar with oil's Viscosity Rating—10W40, for example. However, very few know that the "W" refers to "winter," not "weight." And most of us have no idea what the weight-rating numbers mean other than that the vehicle's manufacturer specifies a particular viscosity. This story deals strictly with viscosity; we're saving the petroleum vs. synthetic debate for later.

Oil Duties | Back To Top
Inside an engine, oil is in a Catch-22 scenario: It has to seal rings and valves, but it also must reduce friction. In simple terms, oil has to accomplish two functions that have directly opposite requirements.

The viscosity of any oil changes with temperature. The higher the temperature, the lower the viscosity—the oil thins out. On the flipside, the lower the temperature the higher the viscosity. Because of this, the Society of Automotive Engineers (SAE) has established a series of viscosity classifications that establish oil performance at 100 and 0 degrees Celsius (212 and 32 degrees Fahrenheit, respectively).

Highs and Lows | Back To Top
Low-viscosity oils flow better than high-viscosity ones—the lighter-weight fluid is easier to pump and therefore circulates faster through the engine's various galleries. Low-viscosity oils also maintain a lower oil pressure, but the oil pump delivers a greater volume through the galleries than it would with thicker (higher-viscosity) oils. Heavier oils also tend to operate at higher temperatures because the oil pump has to work harder to force the lubricant through the system. Oil does not compress readily, so the added pressure increases the temperature. In the end, high-viscosity oils maintain a higher oil pressure, but the pump delivers a smaller volume of oil.

Multigrades | Back To Top
Multigrade oils typically begin as base oils, such as 10W. Then viscosity-index modifiers (polymers) are added in an effort to stabilize the viscosity. This allows a 10W40 oil to flow like a 10W at cold temperatures and a 40W at higher temperatures.

The multigrade oils' viscosity modifiers are long-chain molecules that lessen the change of viscosity with temperature variance. In the past, the polymer additives (used to thicken the oil) were sometimes susceptible to viscosity loss. Permanent viscosity loss occurred when high shear forces (such as the relationship between the main bearings and the crankshaft) actually break the polymer molecules into less-effective smaller pieces. On a similar note, temporary viscosity loss also occurred when the polymer molecules aligned themselves in order to create a path of least resistance.

Fortunately, today's additive packages have improved oil's shear-resistance. However, oils with the same rating from different manufacturers can exhibit different viscosity ratings in an operating engine, depending on the shear stability of their viscosity-modifying additives.

For technoids, weights are defined thusly (stokes and centistrokes are measurements of viscosity):

"SAE 30 is SAE 30 no matter what the "W" prefix number is: 0W, 5W or 10W. This viscosity in centistokes (cSt) @ 100 degrees C is with the minimum of 9.3 cSt and a maximum of 12.5 cSt.

"SAE 40 is SAE 40 no matter what the "W" prefix number is: 5W, 10W, 15W or 20W. The viscosity @ 100 degrees C is within the minim of 12.5 cSt and a maximum of 16.3 cSt.

"SAE 50 is SAE 50 no matter what the "W" prefix number is: 5W, 10W, 15W or 25W. The viscosity @ 100 degrees C is within the minimum of 16.3 cSt and a maximum of 21.9 cSt.

"SAE 60 is SAE 60 no matter what the "W" prefix number is: 10W, 15W or 25W. The viscosity @ 100 degrees C is within the minimum of 21.9 cSt and a maximum of 26.1 cSt.

"There is no SAE 70 and no one is likely to make one with a "W" prefix number although it is possible using a synthetic base oil. This viscosity is identified as Grade 70. The viscosity @ 100 degrees C has a minimum of 26.1 cSt and no maximum."

The difference between a multigrade and a singlegrade oil: The singlegrade can't pass the low temperature viscosity test. If it did meet one of the following "W" viscosities, it would be a multigrade.

Singlegrade oils will become obsolete for performance engines in the future. We dropped SAE 30 and SAE 40 because SAE 10W40 does everything 30 or 40 can do—and some things the straight grades can't do—like increasing horsepower. If an off-roader doesn't like 10W40, then use 20W50. It can do everything a 10W40 can do except pass the sub-zero viscosity test at -20 degrees C.

Multigrade viscosities are run at six different sub-zero temperatures. When a racing-oil designer puts a formula together, he has to know the viscosity at 100 degrees C of every component in the additive composition. He has to have a target viscosity objective for the finished oil in each SAE grade. Once a formula is established, the technician who supervises the blending has to duplicate this formula in the correct proportions every time the product is blended. The viscosity at 100 degrees C has a plus or minus written into the oil's quality-control specification.

Multigrade or Multi-Vis? | Back To Top
One oil manufacturer claims that "some people in the industry use multi-viscosity as if it means the same thing as multigrade. An oil cannot be multi-viscosity, but it can be multigrade by meeting the viscosity requirements for SAE 30, 40, 50 or 60 and one of the sub-zero "W" viscosity requirements. At one time, some oil companies labeled oils SAE 10W, 20W30—as if the oil could be 10W and 20W at the same time. This is impossible because 10W is measured at -20 degrees C and 20W is measured at -10 degrees C, which eliminates the multi-viscosity theory."

API Numbers | Back To Top
Shortly after WWII, the American Petroleum Institute (API) developed a system that established three basic types of engine oils: regular, premium and heavy-duty. Naturally, three oil classifications could never hope to cover all of the different applications ranging from conventional passenger cars to heavy-duty trucks. The API eventually realized that other variables had to be considered, such as the type of engine and its usage. In 1952, the API launched the service classifications system.

The API system revolves around two general classification: S for Service (typical passenger cars and light trucks) and C for commercial applications (typical diesel equipment). The breakdown of "S" varieties is as follows:

SA: This is a plain mineral oil that doesn't contain additives common in today's high-tech lubricants. This oil was primarily used in the 1920s and is obsolete today.

SB: Lubes that contain anti-wear and oxidation inhibitors as well as corrosion inhibitors. This oil was primarily in use prior to 1964 and was created for vehicles that saw moderate conditions.

SC: This classification was originally recommended for use in 1964-67 vehicles. It contains additives that control rust, wear, corrosion and engine deposits. It too is now obsolete.

SD: SD lubes were recommended for use in 1968-70 vehicles as well as certain post-1970 passenger cars. This oil contains the same additive packages as the SC class and can be used in place of it.

SE: This category was recommended for certain 1971 vehicles as well as most 1972 vehicles. This classification offers more protection than the SD group of lubricants and is suitable for severe-duty applications. This classification can be used in place of SD oils.

SF: Recommended with 1980 and newer passenger vehicles. This oil has superior anti-wear properties and enhanced oxidation stability over SE lubricants.

SG: The SG rating was introduced in 1989 and combined the performance properties of the commercial rating CC (lubricants designed for use in supercharged/turbocharged diesel applications in moderate to severe service).

SH: Now obsolete, SH was designed for 1996 and older engines.

SJ: Introduced in 1996, this rating is for all automotive engines presently in use.

Generally speaking, think of the API system as a blueprint for oil. In order to gain an API classification, oil manufacturers have to follow a set of limitations. This creates a few problems for oil companies, especially those who produce racing oils. Race oil must conform to viscosity-grade standards but not to those for chemical-additive composition and base-oil composition. That's why you'll find several brands of race oil without API classifications.

Race Oil | Back To Top
In the old days, high-performance "racing" oils were generally sold in a straight 50 grade. Today, you have much more choice. There are dozens upon dozens of oils to choose from (even from one manufacturer or "packager"). According to Torco, five questions should influence your selection of oil viscosity:

(1) Does the engine operate on racing gasoline, alcohol or nitromethane? (2) Is the powerplant normally aspirated, turbocharged or supercharged? (3) Is there an oxidizer such as nitrous oxide or propylene oxide present? (4) How long will the engine be running and if racing, what is the duration of the race? (5) How often is the oil changed?

The following are suggestions for viscosity based upon the format of racing. In these maximum-horsepower applications, the suggestions are based upon the assumption that synthetic oils are used.

Resources | Back To Top


Torco International, (800) 649 5722, www.torcoracingoils.com

Amsoil, www.amsoil.com

Castrol, www.castrol.com

Chevron, www.chevron.com

Citgo, www.citgo.com

Coastal Unilube, www.coastalunilube.com

ExxonMobil, www.exxon.com

Kendall/Sunoco, www.kendallmotoroil.com

Neo, www.neosyntheticoil.com

Pennzoil/Quaker State, www.pennzoilquakerstate.com

Phillips 66, www.tropartic.com

Red Line, www.redlineoil.com

Royal Purple, www.synerlec.com

Texaco/Shell, www.texaco.com

Torco, www.torcoracingoils.com

Valvoline,

[Howard]

Ron, that was the link I posted (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)
But my real questions are:
Overfill type 4's?
Everything I've read says that lower viscosity oil has less 'drag' and better cooling properties due to faster circulation.
How much oil pressure is enough, and is higher viscosity oil worth those penalties?

[SLITS]

The post was not aimed at you Howie......One of these days the junior engineers might actually visit a library and read up on subjects...but then they would have to leave their cozy dorms, apartments or the party.

lower viscosity.....lower drag, less hp to turn the pump.....ding.....True

Better cooling....increased speed is not an indicator of better cooling...moving faster it just doesn't pick up as much heat from a surface....there is an optimum "rate of flow" for aided cooling.....Ding.....not true.

How much oil pressure?....Chevrolet engineers measured the oil pressure at the interface of the babbit material and crankshaft so many moons ago...afair, the pressure was 5000+ psi. I've seen guys run with 10 psig and 10W oil (straight grade). We targeted 55 psig @ 5500 in our race cars. We ran straight 50W dino oil (valvoline racing (IMG:http://www.914world.com/bbs2/html/emoticons/av-943.gif) oil). This was a "wet sump" system. Oil temps 220 - 230.

Street car...I would be comfortable with a constant 30 psig running above 2000 rpm


I overfill my street car up to 1/2 quart if I'm gonna be slogging a race course or parking lot (or country road without cops). I don't care if I get a little cylinder charge contamination from overfilling...I don't want to see the light in a hard corner. We over filled the race cars 1 quart from stock (we had crank scrappers, windage trays and puke cans too!)

The above is my opinion and observations only....

PS...my favorite oil was Castrol R.....stickier that shit, had a nice smell when it burned...was a great aid to constipation.

[Howard]

(IMG:http://www.914world.com/bbs2/html/emoticons/laugh.gif)
Agree with you on the bean oil. Followed and older 356 running Castrol R. That and the unburned hydrocarbons are my idea of perfume.

[bd1308]

dont worry, soon i'll be here less...cant do school, full-time work and 914 stuff....

i still dont see hwo what i said differs from the other information presented.

b

[SLITS]

Britt....quit worrying. We're not ego centered here (IMG:http://www.914world.com/bbs2/html/emoticons/av-943.gif)

However, those Canadians..............

[Howard]

QUOTE (sk8kat1 @ Jan 15 2006, 03:40 PM)

when I am stopped on a decline or if I comne to a hard stop the oil light flickers ?! I chkd to see the oil is at the bottom narker ... 1) what oil is to be added to the car 5w 30 -- 10w40? ..... is there any thing else I should chk as well ?

Britt, I was just aiming at the original post, not you. I think the oil pressure light went on because the oil LEVEL was low. Braking or turning hard with the oil at the lower marker was my guess. The oil pickup is usually positioned toward the rear of sump so you won't suck dry under acceleration (when the greatest strain is on the engine).

As per Ron, the great guru of all things, keep a type 4 full or a little over.

[Mueller]

back to the original posting (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

for the /4 motors, it's common practice and recommended to run 1/2 quart extra oil (or is that 1 pint or 2 cups?, hahahaha)

[reverie]

Re multigrade oils -

The lower viscosity is for when the engine is cold - when most engine wear occurs - and the lower viscosity is needed to lubricate the parts faster. Higher viscosity would cause more engine wear when the engine is cold.

[Bleyseng]

more info...

"When the car was new, Porsche recommended single-grade oils for these cars, SAE 30 for the summer and either SAE 20 or SAE 20W-20 in the winter for temperatures from +5F to 32F (-15C to 0C), of SAE 10 for constant temperatures below +5F (+15C). Normally, I recommend that you follow the suggestions in the owners manuals, but a lot has changed in the past twenty or so years.

Porsche revised its oil recommendations for these early cars about ten years ago to a multi-grade oil. The engines in these older cars were built for use with motor oils which were available at the time these cars were built. Because these earlier oils were thicker than what is usually available today, the engines internal clearances were greater than the more modern engines built since the mid seventies. Porsche also recommends not using synthetic oils in these early engines because of different types of seal and gasket materials used in them.

The cars affected by these updated recommendations are: the Type 356 (all 356, 356A, 356B, and 356C). Type 912, Type 914-4 and 916-6 (and the 916), Type 901, and Type 911 through 2.4-liter models built in 1973. The new recommendations are:

For Summer or warm climates:
SAE20W-50
SAE20W-40
SAE40
For Winter use and in cold climates:
SAE 15W-40
SAE 10W-30


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