Oil Change Time
#1
Le Mans Master
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Oil Change Time
86 iron head 36k miles
I read alot of past threads where the advice is 10/30 or 10/40... Mine says 5/30 in the manual and on the fill cap.... not a word about synthetic in the manual. I dont even think synthetic was around at that time was it? I haven't had a flat tappet engine in a long time. I plan on conventional... and probably 5/30.. When I had my ZR-1 I used a Amsoil with a higher zinc content. Should I be thinking along those lines? I dont know what type of oil the PO used...
I read alot of past threads where the advice is 10/30 or 10/40... Mine says 5/30 in the manual and on the fill cap.... not a word about synthetic in the manual. I dont even think synthetic was around at that time was it? I haven't had a flat tappet engine in a long time. I plan on conventional... and probably 5/30.. When I had my ZR-1 I used a Amsoil with a higher zinc content. Should I be thinking along those lines? I dont know what type of oil the PO used...
#2
Le Mans Master
86 iron head 36k miles
I read alot of past threads where the advice is 10/30 or 10/40... Mine says 5/30 in the manual and on the fill cap.... not a word about synthetic in the manual. I dont even think synthetic was around at that time was it? I haven't had a flat tappet engine in a long time. I plan on conventional... and probably 5/30.. When I had my ZR-1 I used a Amsoil with a higher zinc content. Should I be thinking along those lines? I dont know what type of oil the PO used...
I read alot of past threads where the advice is 10/30 or 10/40... Mine says 5/30 in the manual and on the fill cap.... not a word about synthetic in the manual. I dont even think synthetic was around at that time was it? I haven't had a flat tappet engine in a long time. I plan on conventional... and probably 5/30.. When I had my ZR-1 I used a Amsoil with a higher zinc content. Should I be thinking along those lines? I dont know what type of oil the PO used...
#3
Team Owner
Pro Mechanic
86 iron head 36k miles
I read alot of past threads where the advice is 10/30 or 10/40... Mine says 5/30 in the manual and on the fill cap.... not a word about synthetic in the manual. I dont even think synthetic was around at that time was it? I haven't had a flat tappet engine in a long time. I plan on conventional... and probably 5/30.. When I had my ZR-1 I used a Amsoil with a higher zinc content. Should I be thinking along those lines? I dont know what type of oil the PO used...
I read alot of past threads where the advice is 10/30 or 10/40... Mine says 5/30 in the manual and on the fill cap.... not a word about synthetic in the manual. I dont even think synthetic was around at that time was it? I haven't had a flat tappet engine in a long time. I plan on conventional... and probably 5/30.. When I had my ZR-1 I used a Amsoil with a higher zinc content. Should I be thinking along those lines? I dont know what type of oil the PO used...
Use the recommended oil or better (5w/30) and change at the proper intervals...your engine will cruise right on by 300,000 miles easy.
#4
Melting Slicks
If you want to be over the top with a large quantity of zinc 1) Amsoil Z-Rod 10w30, if you want a good synthetic at a reasonable price with a good amount of zinc 2) Mobil 1 0w-40, if your on a budget 3) Shell Rotella 15w-40.
People who tell you the oil quality is better today don't have a clue what they are talking about. The zinc content has been on the decline since the 90s. All 20 and 30wt oils unless you get a specialized oil (Z-rod, Brad Penn) have barely half the amount of zinc a flat tappet engine requires. 40 and 50wt oils are not required to reduce the amounts of zinc.
People who tell you the oil quality is better today don't have a clue what they are talking about. The zinc content has been on the decline since the 90s. All 20 and 30wt oils unless you get a specialized oil (Z-rod, Brad Penn) have barely half the amount of zinc a flat tappet engine requires. 40 and 50wt oils are not required to reduce the amounts of zinc.
#5
Team Owner
Pro Mechanic
Here is a read for you, and I'd put way....way....WAY more stock in this guys post....than the gem that you just laid down.
My Analysis of the Use of Low Zinc (zddp) Oil in C4 Corvettes
HERE is the catalyst for that well researched and articulated post. I made the same argument back then (today's oils are way better than good enough) and after his research, the other poster Jim Rogers, agreed.
Today's oil is way better than "good enough". How long do you need an engine to last? My '96 Silverado has 296,000....HARD miles on it, yet still performs as new. How much better would it perform had I used "yesterday's oils"?
.
Last edited by Tom400CFI; 07-07-2017 at 10:57 AM.
#6
Melting Slicks
Appearatly not. That 'article' was written in 2014 and the 20 and 30wt oils today are in the 6-700ppm zinc range. I wouldn't chance my motor with that.
Ummm FYI ill let you in on a lil secret your 96 Silverado is a ROLLER motor
Ummm FYI ill let you in on a lil secret your 96 Silverado is a ROLLER motor
#7
Team Owner
Pro Mechanic
Sorry that I used a roller motor as one example of an engine that has lasted way longer than long enough. How about my boat; '92 Ford 351w. That's a flat tappet cam. Runs like the day it was delivered. It's 25 years old now...How long is "long enough"? How good is "good enough"? I mean...that is just one example. I manage a fleet. We have some gas/flat tappet cam trucks that date back to 1987...30 years old! Somehow...they manage to make it through each day, even on "today's" inferior oils!
#8
here's a cut and paste from bob the oil guy's site and forum. read in detail the paragraphs on the Starburst Oil Myth as it relates to zinc -
Over the years there has been an overabundance of engine oil myths. Here are some facts you may want to pass along to customers to help debunk the fiction behind these myths.
The Pennsylvania Crude Myth -- This myth is based on a misapplication of truth. In 1859, the first commercially successful oil well was drilled in Titusville, Pennsylvania.
A myth got started before World War II claiming that the only good oils were those made from pure Pennsylvania crude oil. At the time, only minimal refining was used to make engine oil from crude oil. Under these refining conditions, Pennsylvania crude oil made better engine oil than Texas crude or California crude. Today, with modern refining methods, almost any crude can be made into good engine oil.
Other engine oil myths are based on the notion that the new and the unfamiliar are somehow "bad."
The Detergent Oil Myth -- The next myth to appear is that modern detergent engine oils are bad for older engines. This one got started after World War II, when the government no longer needed all of the available detergent oil for the war effort, and detergent oil hit the market as “heavy-duty” oil.
Many pre-war cars had been driven way past their normal life, their engines were full of sludge and deposits, and the piston rings were completely worn out. Massive piston deposits were the only thing standing between merely high oil consumption and horrendous oil consumption. After a thorough purge by the new detergent oil, increased oil consumption was a possible consequence.
If detergent oils had been available to the public during the war, preventing the massive deposit buildup from occurring in the first place, this myth never would have started. Amazingly, there are still a few people today, 60 years later, who believe that they need to use non-detergent oil in their older cars. Apparently, it takes many years for an oil myth to die.
The Synthetic Oil Myth -- Then there is the myth that new engine break-in will not occur with synthetic oils. This one was apparently started by an aircraft engine manufacturer who put out a bulletin that said so. The fact is that Mobil 1 synthetic oil has been the factory-fill for many thousands of engines. Clearly, they have broken in quite well, and that should put this one to rest.
The Starburst Oil Myth -- The latest myth promoted by the antique and collector car press says that new Starburst/ API SM engine oils (called Starburst for the shape of the symbol on the container) are bad for older engines because the amount of anti-wear additive in them has been reduced. The anti-wear additive being discussed is zinc dithiophosphate (ZDP).
Before debunking this myth, we need to look at the history of ZDP usage. For over 60 years, ZDP has been used as an additive in engine oils to provide wear protection and oxidation stability.
ZDP was first added to engine oil to control copper/lead bearing corrosion. Oils with a phosphorus level in the 0.03% range passed a corrosion test introduced in 1942.
In the mid-1950s, when the use of high-lift camshafts increased the potential for scuffing and wear, the phosphorus level contributed by ZDP was increased to the 0.08% range.
In addition, the industry developed a battery of oil tests (called sequences), two of which were valve-train scuffing and wear tests.
A higher level of ZDP was good for flat-tappet valve-train scuffing and wear, but it turned out that more was not better. Although break-in scuffing was reduced by using more phosphorus, longer-term wear increased when phosphorus rose above 0.14%. And, at about 0.20% phosphorus, the ZDP started attacking the grain boundaries in the iron, resulting in camshaft spalling.
By the 1970s, increased antioxidancy was needed to protect the oil in high-load engines, which otherwise could thicken to a point where the engine could no longer pump it. Because ZDP was an inexpensive and effective antioxidant, it was used to place the phosphorus level in the 0.10% range.
However, phosphorus is a poison for exhaust catalysts. So, ZDP levels have been reduced over the last 10-15 years. It's now down to a maximum of 0.08% for Starburst oils. This was supported by the introduction of modern ashless antioxidants that contain no phosphorus.
Enough history. Let's get back to the myth that Starburst oils are no good for older engines. The argument put forth is that while these oils work perfectly well in modern, gasoline engines equipped with roller camshafts, they will cause catastrophic wear in older engines equipped with flat-tappet camshafts.
The facts say otherwise.
Backward compatability was of great importance when the Starburst oil standards were developed by a group of experts from the OEMs, oil companies, and oil additive companies. In addition, multiple oil and additive companies ran no-harm tests on older engines with the new oils; and no problems were uncovered.
The new Starburst specification contains two valve-train wear tests. All Starburst oil formulations must pass these two tests.
- Sequence IVA tests for camshaft scuffing and wear using a single overhead camshaft engine with slider finger (not roller) followers.
- Sequence IIIG evaluates cam and lifter wear using a V6 engine with a flat-tappet system, similar to those used in the 1980s.
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.)
Despite the pains taken in developing special flat-tappet camshaft wear tests that these new oils must pass and the fact that the ZDP level of these new oils is comparable to the level found necessary to protect flat-tappet camshafts in the past, there will still be those who want to believe the myth that new oils will wear out older engines.
Like other myths before it, history teaches us that it will probably take 60 or 70 years for this one to die also.
Special thanks to GM's Techlink
- Thanks to Bob Olree – GM Powertrain Fuels and Lubricants Group
The Pennsylvania Crude Myth -- This myth is based on a misapplication of truth. In 1859, the first commercially successful oil well was drilled in Titusville, Pennsylvania.
A myth got started before World War II claiming that the only good oils were those made from pure Pennsylvania crude oil. At the time, only minimal refining was used to make engine oil from crude oil. Under these refining conditions, Pennsylvania crude oil made better engine oil than Texas crude or California crude. Today, with modern refining methods, almost any crude can be made into good engine oil.
Other engine oil myths are based on the notion that the new and the unfamiliar are somehow "bad."
The Detergent Oil Myth -- The next myth to appear is that modern detergent engine oils are bad for older engines. This one got started after World War II, when the government no longer needed all of the available detergent oil for the war effort, and detergent oil hit the market as “heavy-duty” oil.
Many pre-war cars had been driven way past their normal life, their engines were full of sludge and deposits, and the piston rings were completely worn out. Massive piston deposits were the only thing standing between merely high oil consumption and horrendous oil consumption. After a thorough purge by the new detergent oil, increased oil consumption was a possible consequence.
If detergent oils had been available to the public during the war, preventing the massive deposit buildup from occurring in the first place, this myth never would have started. Amazingly, there are still a few people today, 60 years later, who believe that they need to use non-detergent oil in their older cars. Apparently, it takes many years for an oil myth to die.
The Synthetic Oil Myth -- Then there is the myth that new engine break-in will not occur with synthetic oils. This one was apparently started by an aircraft engine manufacturer who put out a bulletin that said so. The fact is that Mobil 1 synthetic oil has been the factory-fill for many thousands of engines. Clearly, they have broken in quite well, and that should put this one to rest.
The Starburst Oil Myth -- The latest myth promoted by the antique and collector car press says that new Starburst/ API SM engine oils (called Starburst for the shape of the symbol on the container) are bad for older engines because the amount of anti-wear additive in them has been reduced. The anti-wear additive being discussed is zinc dithiophosphate (ZDP).
Before debunking this myth, we need to look at the history of ZDP usage. For over 60 years, ZDP has been used as an additive in engine oils to provide wear protection and oxidation stability.
ZDP was first added to engine oil to control copper/lead bearing corrosion. Oils with a phosphorus level in the 0.03% range passed a corrosion test introduced in 1942.
In the mid-1950s, when the use of high-lift camshafts increased the potential for scuffing and wear, the phosphorus level contributed by ZDP was increased to the 0.08% range.
In addition, the industry developed a battery of oil tests (called sequences), two of which were valve-train scuffing and wear tests.
A higher level of ZDP was good for flat-tappet valve-train scuffing and wear, but it turned out that more was not better. Although break-in scuffing was reduced by using more phosphorus, longer-term wear increased when phosphorus rose above 0.14%. And, at about 0.20% phosphorus, the ZDP started attacking the grain boundaries in the iron, resulting in camshaft spalling.
By the 1970s, increased antioxidancy was needed to protect the oil in high-load engines, which otherwise could thicken to a point where the engine could no longer pump it. Because ZDP was an inexpensive and effective antioxidant, it was used to place the phosphorus level in the 0.10% range.
However, phosphorus is a poison for exhaust catalysts. So, ZDP levels have been reduced over the last 10-15 years. It's now down to a maximum of 0.08% for Starburst oils. This was supported by the introduction of modern ashless antioxidants that contain no phosphorus.
Enough history. Let's get back to the myth that Starburst oils are no good for older engines. The argument put forth is that while these oils work perfectly well in modern, gasoline engines equipped with roller camshafts, they will cause catastrophic wear in older engines equipped with flat-tappet camshafts.
The facts say otherwise.
Backward compatability was of great importance when the Starburst oil standards were developed by a group of experts from the OEMs, oil companies, and oil additive companies. In addition, multiple oil and additive companies ran no-harm tests on older engines with the new oils; and no problems were uncovered.
The new Starburst specification contains two valve-train wear tests. All Starburst oil formulations must pass these two tests.
- Sequence IVA tests for camshaft scuffing and wear using a single overhead camshaft engine with slider finger (not roller) followers.
- Sequence IIIG evaluates cam and lifter wear using a V6 engine with a flat-tappet system, similar to those used in the 1980s.
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.)
Despite the pains taken in developing special flat-tappet camshaft wear tests that these new oils must pass and the fact that the ZDP level of these new oils is comparable to the level found necessary to protect flat-tappet camshafts in the past, there will still be those who want to believe the myth that new oils will wear out older engines.
Like other myths before it, history teaches us that it will probably take 60 or 70 years for this one to die also.
Special thanks to GM's Techlink
- Thanks to Bob Olree – GM Powertrain Fuels and Lubricants Group
Last edited by Joe C; 07-07-2017 at 12:49 PM.
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Tom400CFI (07-07-2017)
#9
Team Owner
Pro Mechanic
^This.
If new engine oils aren't any good...if "I wouldn't chance my motor with that." -where legitimate....then where are the failures? Where are the worn out motors? In fact, engines today are lasting longer than they have in the history of internal combustion engines. Why? Because technology and a century of refining experience allow today's oils to be better than ever.
OP can pick any quality brand he wants, used the recommended weight, change at proper intervals....and cruise right on by 300k.
If new engine oils aren't any good...if "I wouldn't chance my motor with that." -where legitimate....then where are the failures? Where are the worn out motors? In fact, engines today are lasting longer than they have in the history of internal combustion engines. Why? Because technology and a century of refining experience allow today's oils to be better than ever.
OP can pick any quality brand he wants, used the recommended weight, change at proper intervals....and cruise right on by 300k.
#10
Melting Slicks
Member Since: Nov 2013
Location: Greater Cincinnati Area.
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I use the Mobil One High Mileage. Phosphorous/Zinc is 800/900 PPM.
https://mobiloil.com/~/media/amer/us...pecs-guide.pdf
https://mobiloil.com/~/media/amer/us...pecs-guide.pdf
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Tom400CFI (07-07-2017)
#14
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All Mobil 1 is synthetic correct? I don't want to use synthetic oil in this engine. It wasn't built with that in mind and it wasn't delivered to the dealer with synthetic.... and I'm not putting it in there either.... I don't know what the PO was using, but I would bet it was the less expensive option of conventional.... Don't want to upset the apple cart at this stage of the game if you know what I mean...
#15
All Mobil 1 is synthetic correct? I don't want to use synthetic oil in this engine. It wasn't built with that in mind and it wasn't delivered to the dealer with synthetic.... and I'm not putting it in there either.... I don't know what the PO was using, but I would bet it was the less expensive option of conventional.... Don't want to upset the apple cart at this stage of the game if you know what I mean...
#18
Melting Slicks
All Mobil 1 is synthetic correct? I don't want to use synthetic oil in this engine. It wasn't built with that in mind and it wasn't delivered to the dealer with synthetic.... and I'm not putting it in there either.... I don't know what the PO was using, but I would bet it was the less expensive option of conventional.... Don't want to upset the apple cart at this stage of the game if you know what I mean...
The reason the L98s came with Dino oil is because they have factory oil coolers (KC4 I believe?). In 1992 GM stopped installing oil coolers in Corvettes then guess what? YEP Mobil 1 synthetic became the factory fill.
#20
Team Owner
Pro Mechanic
It's just a rating number. It doesn't mean that the oil is as thin as break cleaner. It's just a number that is applied to the flowability of the oil at a certain temp.
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confab (07-07-2017)