..I use synthetic oil.....Royal Purple.....is zinc missing from my oil and can this cause problems for my engine??? 
engine oil
Thread Starter
Instructor
Joined: Feb 2012
Posts: 216
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From: Hemet California
Thank you everyone for your imput.
Yes I am a new member on this forum but not new to the car collecting hobby. I have been collecting and working on my cars for over 45 years. Most have been from the 1940s and 1950s vintage.
I had a 1968 Corvette that I used as a daily driver during the late 60s and early 70s. I always regreted that I chose to sell my 68.
I fell in love with the C-4 Corvettes when they first came out and dreamed of owning one some day.
I recently retired and a couple of weeks ago had the opertunity to purchase a C-4 Corvette to enjoy during my retirement.
My question was based on my knowledge of older cars and the changes that I understand took place between 1986 and 1987 . 383 vett and kubs understood where I was coming from my question.
Yes I am a new member on this forum but not new to the car collecting hobby. I have been collecting and working on my cars for over 45 years. Most have been from the 1940s and 1950s vintage.
I had a 1968 Corvette that I used as a daily driver during the late 60s and early 70s. I always regreted that I chose to sell my 68.
I fell in love with the C-4 Corvettes when they first came out and dreamed of owning one some day.
I recently retired and a couple of weeks ago had the opertunity to purchase a C-4 Corvette to enjoy during my retirement.
My question was based on my knowledge of older cars and the changes that I understand took place between 1986 and 1987 . 383 vett and kubs understood where I was coming from my question.
Last edited by Jerry Roubos; Jul 26, 2012 at 04:53 PM.
Race Director
Joined: Apr 2000
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From: Texas
Thank you everyone for your imput.
Yes I am a new member on this forum but not new to the car collecting hobby. I have been collecting and working on my cars for over 45 years. Most have been from the 1940s and 1950s vintage.
I had a 1968 Corvette that I used as a daily driver during the late 60s and early 70s. I always regreted that I chose to sell my 68.
I fell in love with the C-4 Corvettes when they first came out and dreamed of owning one some day.
I recently retired and a couple of weeks ago had the opertunity to purchase a C-4 Corvette to enjoy during my retirement.
My question was based on my knowledge of older cars and the changes that I understand took place between 1986 and 1987 . 383 vett and kubs understood where I was coming from my question.
Yes I am a new member on this forum but not new to the car collecting hobby. I have been collecting and working on my cars for over 45 years. Most have been from the 1940s and 1950s vintage.
I had a 1968 Corvette that I used as a daily driver during the late 60s and early 70s. I always regreted that I chose to sell my 68.
I fell in love with the C-4 Corvettes when they first came out and dreamed of owning one some day.
I recently retired and a couple of weeks ago had the opertunity to purchase a C-4 Corvette to enjoy during my retirement.
My question was based on my knowledge of older cars and the changes that I understand took place between 1986 and 1987 . 383 vett and kubs understood where I was coming from my question.
The point/frustration is that "oil" has been discussed on this forum, other forums, and across the internet millions of times. Over the last month, there have been multiple threads within C4 Gen and C4 Tech on oil. A 2 second internet search will tell you everything you need to know about oil grades, weights, and standards...
What Oil Should I use?
Grades:
"The latest API service standard designation is SN for gasoline automobile and light-truck engines. The SN standard refers to a group of laboratory and engine tests, including the latest series for control of high-temperature deposits. Current API service categories include SN, SM, SL and SJ for gasoline engines. All previous service designations are obsolete, although motorcycle oils commonly still use the SF/SG standard.
All the current gasoline categories (including the obsolete SH), have placed limitations on the phosphorus content for certain SAE viscosity grades (the xW-20, xW-30) due to the chemical poisoning that phosphorus has on catalytic converters. Phosphorus is a key anti-wear component in motor oil and is usually found in motor oil in the form of zinc dithiophosphate. Each new API category has placed successively lower phosphorus and zinc limits, and thus has created a controversial issue of obsolescent oils needed for older engines, especially engines with sliding (flat/cleave) tappets. API, and ILSAC, which represents most of the worlds major automobile/engine manufactures, states API SM/ILSAC GF-4 is fully backwards compatible, and it is noted that one of the engine tests required for API SM, the Sequence IVA, is a sliding tappet design to test specifically for cam wear protection. Not everyone is in agreement with backwards compatibility, and in addition, there are special situations, such as "performance" engines or fully race built engines, where the engine protection requirements are above and beyond API/ILSAC requirements. Because of this, there are specialty oils out in the market place with higher than API allowed phosphorus levels. Most engines built before 1985 have the flat/cleave bearing style systems of construction, which is sensitive to reducing zinc and phosphorus. Example; in API SG rated oils, this was at the 1200-1300 ppm level for zinc and phosphorus, where the current SM is under 600 ppm. This reduction in anti-wear chemicals in oil has caused premature failures of camshafts and other high pressure bearings in many older automobiles and has been blamed for pre-mature failure of the oil pump drive/cam position sensor gear that is meshed with camshaft gear in some modern engines."
Even with all of the above, at the end of the day, it boils down to preference. Some like conventional, some like synthetic, some like race oils.
...and Sweet is right. A little sense of humor makes for more fun. Usually when the teasing starts....it's because a topic has been beaten to a bloody pulp and someone is expecting the forum to press their computer keys for them and do a simple search.
Last edited by 96GS#007; Jul 26, 2012 at 05:06 PM.
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What year car? The Zinc isn't "missing", but there is a limit to how much is in most synthetics. It is not a big deal for regular street driven roller cam engines, but for racing engines or flat tappet cam engines the added ZDDP is needed to prevent excessive wear on critical parts.
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From: Crystal Springs MS
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From: Greenville SC
I have been running Mobil 1 high mileage in my 84 for the past year or so (don't drive that much) and it has worked well to reduce the rear main seal leak to an occasional drip. It might have a bit more ZDDP, but I don't have the spec sheets at hand to compare. Dave
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From: Colorado
When I change my oil next do you guys recommend I switch to Mobile1 high mileage?
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From: Hamilton Ohio
I think some of you are missing the point made about ZDDP levels in oil. If he has flat tappets then the newer oils don't have enough. Talk to the guy's with small block motors that didn't know about the reduction of ZDDP and had cam failures. Old flat tappet motors do need a special oil.
Race Director
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From: United States
Shell Rotella T6 is a very good oil with a good amount of ZDDP.
You have a roller cam in there, so it really isnt a big deal about the ZDDP.
But, Jiffy Lube will get you going just fine..
You have a roller cam in there, so it really isnt a big deal about the ZDDP.
But, Jiffy Lube will get you going just fine..
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From: Mentor OH
Le Mans Master
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From: South-central Missouri
The op has an 86. I believe that's when GM switched midyear from flat tappet to roller cams. It might be prudent for him to find a motor oil that has the maximum amount of ZDPP or an additive to prevent cam and lifter wear. The op asked a legitimate question and probably doesn't appreciate smart a$$ answers. I know I wouldn't.
It really boils down to FLAT vs. ROLLER tappets, as the turning point for what oil to use.
Flat tappet ZDDP is significantly higher than that needed for roller tappets. (And, I have a (flat tappet) cam (with several wiped lobes) out of my wife's 69 SBC to support what SBC builders have discovered and known for years now.)
As for APIs with the proper ZDDP levels for flat tappets, there are several; Mobil 1 "High Mileage" formula is one, and there are others. Killing a fly with a sledge hammer, Amsoil APO 10W-40 is one with the "right stuff", and they carry another.
This topic seems this comes up every 3 months or so, but a while back there was a good discussion on this topic by a guy in the lube bitness, who went into some of the science of oils; a web Amsoil sponsor, as I recall. Very interesting to those that get into the science of things. A search might find it.
P.
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It really boils down to FLAT vs. ROLLER tappets, as the turning point for what oil to use.
Flat tappet ZDDP is significantly higher than that needed for roller tappets. (And, I have a (flat tappet) cam (with several wiped lobes) out of my wife's 69 SBC to support what SBC builders have discovered and known for years now.)
As for APIs with the proper ZDDP levels for flat tappets, there are several; Mobil 1 "High Mileage" formula is one, and there are others. Killing a fly with a sledge hammer, Amsoil APO 10W-40 is one with the "right stuff", and they carry another.
This topic seems this comes up every 3 months or so, but a while back there was a good discussion on this topic by a guy in the lube bitness, who went into some of the science of oils; a web Amsoil sponsor, as I recall. Very interesting to those that get into the science of things. A search might find it.
P.
Le Mans Master
Joined: Oct 2004
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From: South-central Missouri
