Some useful info

 

 

Here you may find some more or less useful information. Some info applies specificly for the Corvette, and some info is for cars in general. The info found here is collected from different sources, my experience, people I talk to, books and the internet. I will not post info I suspect might be incorrect, however My73corvette.com, or me personally, take no responsibility for inaccurate or faulty information that causes you problems any way. Make use of the information found at this website at your own risk.

If you know for a fact that information on this website is inacurate or faulty, please send me an e-mail, and I will check it out, thanks.

 

 

 

Corvette Restoration

Here is a great site for restoring C3 Corvettes. Link will open in a new window.

Clikk here to visit corvette-restoration.com.

 

Engine # Decoding   (Chevrolet)

Year One has a great site fo how to decode Chevrolet engine numbers.

Clikk here to visit Year One engine # decoding.

 

Ignition specifications

For specifications 1965-1975, you may visit The Poorman's Off Chassis Restoration.com.

 

Year

Engine or Car Model

Spark Plug Type (AC) - Gap

Point Gap

Dwell Angle

Ignition Timing 1

Hot Idle 3

Std. Tran

Auto Tran 2

1969

 

350 300 HP 18

R44 -.035

.019

28-32

 70016

-

350 300 HP 19

R44 -.035

.019

28-32

 

-

600D16

350 350 HP

R44 -.035

.019

28-32

 

 75016

-

350 370 HP

R43-.035

.019

28-32

               20

 75016

-

427 390 HP

R43N-.035

.019

28-32

 

 80011

600D11

427 400 HP

R43N-.035

.019

28-32

 

 80011

600D11

427 425 HP

R43N-.035

.019

28-32

 

 75016

750D16

427 430 HP

R43XL-.035

-

-

       12°    5

100016

-

427 435 HP

R43N-.035

-

-

  

 75016

750D16

1973

350 190 HP

R44T-.035

4

29-31

12°

 900   

600D    

350 250 HP

R44T-.035

4

29-31

  

 900   

700D    

454 275 HP

R44T-.035

4

29-31

 10°

 900   

600D    

 

Firing order: 18436572   (1969 300HP 350 firing order is: 153624)

 

  1 - BTDC - Before top dead center or Mark.

  2 - D=drive   N=neutral

  3 - Where two speeds are listed, lower speed indicates idle solenoid disconnected.

  4- New pointes .019, used .o16. On V8 turn adjusting screw in clockwise until engine misfires, then back off.

  5- Adjust timing at 800 rpm.

11- With A/C on.

16- With A/C off.

18 - With standard trannsmission.

19 - With automatic transmission.

20- With distributor 1111496 set at 12°.

 

OIL Viscosity

The SAE designation for multi-grade oils includes two grade numbers; for example, 10W-30 designates a common multi-grade oil. Historically, the first number associated with the W ('W' is for Winter, not Weight) is not rated at any single temperature. The "10W" means that this oil can be pumped by your engine as well as a single-grade SAE 10 oil can be pumped. "5W" can be pumped at a lower temperature than "10W" and "0W" can be pumped at a lower temperature than "5W". The second number, 30, means that the viscosity of this multi-grade oil at 100 °C (212 °F) operating temperature corresponds to the viscosity of a single-grade 30 oil at same temperature. The governing SAE standard is called SAE J300. This "classic" method of defining the "W" rating has since been replaced with a more technical test where a "cold crank simulator" is used at increasingly lowered temps. A 0W oil is tested at −35 °C (−31 °F), a 5W at −30 °C (−22 °F) and a 10W is tested at −25 °C (−13 °F). The real-world ability of an oil to crank in the cold is diminished soon after put into service.

 

Thicker is better myth

The reason that oil viscosities have gotten thinner is because bearing clearances have become smaller. Using thicker oils will interfere with oil flow and the oil pressure will increase. In a worn engine it may be okay to increase the viscosity of the oil because the bearing clearances have become larger.

Info by nordicgroup.us

 

5W30 versus 10W30
Virtually all new passenger vehicles sold in the U.S. use either 5W30 or 10W30 oil. The difference between the two is that the 5W30 flows better when cold, so if you live in a cold climate or operate your vehicle in a cold climate during the winter months, you should use 5W30 if it is the preferred oil for your vehicle. If you live in a sub-tropical climate and don't operate your vehicle in cold climates, then 10W30 is acceptable as long as the manufacturer specifies that it is permissible to use it.

Info by nordicgroup.us

 

Is there a disadvantage to using an oil that flows better when cold, i.e. 5W30 versus 10W30?
Sometimes, but usually not. The crux of the issue is this: the bigger the difference between the cold oil viscosity and the hot oil viscosity, the more the volume of viscosity modifiers and the less the volume of base stock. If you are good about following the manufacturer's recommended oil change interval then stick with the 5W30 if that is the preferred oil for your vehicle, even if 10W30 is acceptable in warmer climates. Older cars may specify 10W30 only. This is because they need a little more viscosity when cold to keep a protective film on the cylinder walls. There have been instances where the larger amount of viscosity modifiers that are present in 5W30 have broken down due to excessive heat and have left carbon deposits on the valves, but this is extremely rare. The proper fix would be to reduce the excessive heat, but the workaround was to use an oil with less viscosity
modifiers.

Info by nordicgroup.us

 

The Dark Oil Myth
Dark oil does not indicate the need for an oil change. The way modern detergent motor oil works is that minute particles of soot are suspended in the oil. These minute particles pose no danger to your engine, but they cause the oil to darken. A non-detergent oil would stay clearer than a detergent oil because all the soot would be left on the internal engine parts and would create sludge. If you never changed your oil, eventually the oil would no longer be able to suspend any more particles in the oil and sludge would form. Fortunately, by following the manufacturer's recommended oil change interval, you are changing your oil long before the oil has become saturated. Remember, a good oil should get dirty as it does it's work cleaning out the engine. The dispersant should stop all the gunk from depositing in the oil pan.

The only real way to determine whether oil is truly in need of changing is to have an oil analysis performed. Since most people don't want to bother with this, it's acceptable to err heavily on the safe side and simply follow the manufacturer's recommended change interval for severe service. There are still a few cars that specify 3K intervals for severe service, but not many. If you look at countries other than the U.S., the oil recommended change interval is much higher than even the normal interval specified by vehicle manufacturers in the U.S.

Info by nordicgroup.us

 

Advantages of Synthetic 

Synthetic oil was originally developed for high performance racing engines. Mobil tried to popularize synthetic oil for passenger vehicles back in the early 1970's. At the time, Mobil was promoting 20K or 25K oil changes with synthetic, but they soon backed down from this. Synthetic oil is a good choice if you have a vehicle with a high performance engine (in fact synthetic is required for many of these engines). It is also a good choice if your vehicle is operated in extremely cold climates. It has higher resistance to breakdown caused by heat and it flows better in extreme cold. Unfortunately for the synthetic oil industry there is virtually no advantage to using synthetic oil in a non-high performance engine that is operated in moderate climates. You probably could go a bit longer between oil changes with a synthetic, i.e. following the normal service schedule even if you fall into the severe service category, but I wouldn't advise this. In short, synthetic may give you the peace of mind of knowing that you are using an oil that is far better than necessary for your vehicle, but it won't reduce wear or extend the life of the engine. The mistake some people make it to wrongly extrapolate these benefits onto normal engines operated in mild climates, with the ultimate lack of any knowledge being manifested with statements such as "synthetics provide 'Peace of Mind,' or 'Cheap Insurance,'" or other such nonsense.

Info by nordicgroup.us

 

Oil Additives
Do not use any oil additives no matter how much they are hyped on TV. They provide no benefit and can interfere and react with the additives already present in the oil. Some additives have particles that can clog oil passages and clog filters. Common additives that are heavily hyped are Slick 50, Duralube, and Prolong.

Info by nordicgroup.us

 

Zinc / ZPD (ZPPD) - Valvoline

Here is a response from Valvoline regarding zinc:
"Our Valvoline SynPower Full Synthetic products only contain 850ppm of Zinc, but you do not need extra Zinc, unless the vehicle is high performance. Stock applications only require about 750ppm of Zinc to be safe for the cam wear. High performance applications with oversize cams and extra added horsepower will require about 1200ppm of Zinc. Valvoline does not make a synthetic product available for these applications, as we recommend our Valvoline VR1 Racing Oil, which contains 1300ppm of Zinc and 1200ppm of
Phosphorus".

 

Zinc / ZPD (ZPPD) - Quaker State

Here is a response from Quaker State Product Technica Service regarding zinc:

The zinc and phosphorous levels were recently reduced (from the API SL levels) as there has been concerns that the oil that makes its way in to the combustion zone of your engine, carrying these anti-wear metals, were burning and poisoning the catalyst in the catalytic converters. If you are seeking higher zinc and phosphorous contents you may have to look to racing oil. We have a product that is called Pennzoil Racing Motor Oil and is available in SAE 50, 60 and 25W-50. It has approximately 1800-2000 ppm of zinc additive for extra wear protection. Other engine oils with comparable anti wear protection would include Shell Rotella T 15W-40 and Pennzoil Long Life 15W-40. Should you desire to speak with a technical representative to discuss this issue in more detail please call Pennzoil-Quaker State Technical Information at 1-800-458-4998.

 

Zink-tilsetning   (Sorry, in Norwegian only)

Zink er meget viktig i motorer med metall-glidning mot metall som vi typisk ser med "gammel type" kamaksler og løftere hvor løfteren sklir over knastene på kamakselen. Zinken skaper en mye sterkere barriere mellom metallene og beskytter dermed bedre mot slitasje enn en moderne olje med lite eller ingen zink-tilsetning. Grunnen til at innholdet av zink er så mye lavere nå enn før er de etterhvert økte kravene til mindre utslipp av farlige avgasser.
En "rullekam" er i motsetning til den eldre "flate" kammen som er laget i støpejern, laget i stål, og løfteren har et nålelagret hjul som ruller over knasten. Denne type kamaksel/løfter krever ikke et høyere zinkinnhold i oljen. For våre gamle V8-motorer (og ellers veteranmotorer) i Corvette C1, C2 og C3 er det meget viktig for kammens/løfterens levetid å bruke "korrekt " olje eller et tilsetningstoff som vil heve innholdet av zink.

 

OIL Api Serviceclass   (Sorry, in Norwgian only)

Serviceklasser i henhold til API-systemet

API-systemet definerer i første omgang driftsforholdene for forbrenningsmotorer. Systemet er delt inn i flere serviceklasser for bensin- og dieselmotorer.

Betegnelsene i systemet angir hvilke driftsforhold, motortyper mm. en olje egner seg for. Dermed kan f.eks. motorprodusenter lett angi hvilken oljetype som skal brukes til en bestemt motor, f.eks. "For API-service SJ, CD". Systemet utvides gradvis med flere betegnelser for f.eks. nye motorer eller endrede driftsforhold som stiller nye krav til oljekvaliteten.

Betegnelsene for bensinmotorer begynner med S, som står for Service Class. SA betyr altså Service Class A, osv. Begrepet service betyr at oljetypen normalt selges på bensinstasjoner.

Betegnelsene for dieselmotorer begynner med C, som står for Commercial Class. Commercial betyr at oljetypen for det meste brukes innenfor den tunge kjøretøysektoren.

Bensinmotorer:


SA
For motorer som arbeider under så gunstige forhold at det ikke er nødvendig med spesiell beskyttelse via tilsetting av additiver i oljen. Klassen mangler særskilte kvalitetskrav.

SB
For motorer som arbeider under så gunstige forhold at det kun er nødvendig med en viss beskyttelse mot slitasje, lagerkorrosjon og oksidasjon via tilsetting av additiver i oljen. Oljer som oppfyller kravene i denne serviceklassen, er blitt brukt siden 1930-tallet. De gir kun en viss beskyttelse mot slitasje og lagerkorrosjon, samt mot korrosjon av oljen.

SC
For bensinmotorer i personbiler fra 1964-1967 og visse lastebiler som arbeider under forhold som er i overensstemmelse med motorprodusentenes garantivilkår. Oljer som oppfyller kravene i denne klassen, motvirker slitasje, korrosjon og avleiringer ved høye og lave temperaturer.

SD
For bensinmotorer i personbiler fra 1968-1970 og visse lastebiler som arbeider under forhold som er i overensstemmelse med motorprodusentenes garantivilkår. Kan også brukes i senere årsmodeller i henhold til produsentens anbefalinger. Oljer som oppfyller kravene i denne klassen, gir bedre beskyttelse mot slitasje, korrosjon og avleiringer enn oljer i serviceklasse SC. SD-oljer kan derfor også brukes når SC anbefales.

SE
For bensinmotorer i personbiler f.o.m. 1972 og i visse tilfeller fra 1971, som arbeider under forhold som er i overensstemmelse med motorprodusentens garantivilkår. Oljene i denne klassen gir bedre beskyttelse mot oksidasjon, korrosjon og avleiringer enn oljer i serviceklasse SD og SC. SE-oljer kan derfor også brukes når SD eller SC anbefales.

SF
Drift typisk for bensinmotorer i personbiler og visse lastebiler f.o.m. 1980, som vedlikeholdes etter de serviceprogrammene som anbefales av motorprodusentene. Oljer i denne klassen er mer oksidasjonsstabile og gir bedre beskyttelse mot slitasje enn oljer i klasse SE. De gir også god beskyttelse mot avleiringer og korrosjon.

SG
Gir bedre beskyttelse mot oksidasjon, slitasje og korrosjon enn oljer i serviceklasse SF. Oljene i denne klassen oppfyller motorprodusentenes krav fra 1989.

SH
Ble introdusert i 1993 og overgår alle kravene i klasse SG. Er testet i henhold til kravene fra Chemical Manufacturers Association (CMA). Kan brukes i stedet for SG-kvalitet eller tidligere kvalitetsnormer i henhold til API-systemet.

SJ
Ble introdusert i 1997 og er en bensinmotorolje som anbefales til nye og/eller eldre personbiler og vans. Oljen er testet i henhold til CMA, og den anbefales i stedet for SH-kvalitet eller tidligere kvalitetsnormer i henhold til API-systemet.

 

 

 

 

 

 

 

 

Useful info index..

 

Subjects»
Corvette Restoration

Engine # decoding

Ignition spesifications

OIL Viscosity

OIL Thicker is better myth

OIL 5W30 vs 10W30

OIL Disadvantages thin oil?

OIL The dark oil myth

OIL Advantages of synthetic

OIL Additives

OIL Zinc / ZPD - Valvoline

OIL Zinc / ZPD - Quaker State

OIL Zink-tilsetning   (No)

OIL API-systemet   (No)

 

 

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