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Discussion Starter · #1 ·
I was talking with my neighbor today about a 350 motor he’s having rebuilt for a 1998 suburban. He told me that the company doesn’t offer a warranty because they can’t count on the customer to put a zinc additive in the oil. I found on line that zinc hasn’t been used in motor oil since 1980. This sounds fishy to me about the warranty. Anyone have an opinion on this, it won’t affect me either way it just made me curious about the whole zinc thing.
Mike
 

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There is zinc additives and high zinc motor oils available. Sounds to me like whoever is rebuilding it is just coming up with an excuse for a piss poor rebuild. If this is a factory style rebuild being a 1998 it shouldn't even have a flat tappet cam requiring high zinc to begin with.

At minimum if this rebuild shop requires zinc in my opinion they should just require proof of zinc additive or high zinc oil changes.
 

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fyi....
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 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 compatibility 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.
- Thanks to Bob Olree – GM Powertrain Fuels and Lubricants Group
 

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Discussion Starter · #4 ·
I agree with
There is zinc additives and high zinc motor oils available. Sounds to me like whoever is rebuilding it is just coming up with an excuse for a piss poor rebuild. If this is a factory style rebuild being a 1998 it shouldn't even have a flat tappet cam requiring high zinc to begin with.

At minimum if this rebuild shop requires zinc in my opinion they should just require proof of zinc additive or high zinc oil changes.
I have told my neighbor that he needs to find another mechanic, he won’t listen. Thanks for your input
 
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Rebuilt motors are not worth time and expense. You can buy brand new crate GM engine with a warranty and the cost are comparable. If its cheaper for a rebuilt then you got to wonder the quality of the job as most who sell on price use cheap imported parts in order to sell at a low price.
 

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Discussion Starter · #6 ·
@Denali0914, I agree 100%. I told him that exact thing before he ever started dealing with the problem, he wanted to buy local.
 

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I was talking with my neighbor today about a 350 motor he’s having rebuilt for a 1998 suburban. He told me that the company doesn’t offer a warranty because they can’t count on the customer to put a zinc additive in the oil. I found on line that zinc hasn’t been used in motor oil since 1980. This sounds fishy to me about the warranty. Anyone have an opinion on this, it won’t affect me either way it just made me curious about the whole zinc thing.
Mike
Millions of vehicles on the road does not know what zinc is . Zinc aids in breaking in cam shafts and crankshaft. Have you ever heard some use the term " I need to change oil to get breakin oil out " ? Even though it's an aid , you don't want to run I full time. I have put a lot of in freshly built engines. When it was used its only run around the first 1500 miles. Today's engine building lube has the additives that eliminate the use of the heavy metal zinc. Oh by the way pr 1950s autos was running on unleaded gas .FYI
 

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Discussion Starter · #8 ·
Millions of vehicles on the road does not know what zinc is . Zinc aids in breaking in cam shafts and crankshaft. Have you ever heard some use the term " I need to change oil to get breakin oil out " ? Even though it's an aid , you don't want to run I full time. I have put a lot of in freshly built engines. When it was used its only run around the first 1500 miles. Today's engine building lube has the additives that eliminate the use of the heavy metal zinc. Oh by the way pr 1950s autos was running on unleaded gas .FYI
I remember when they started fazing the leaded gasoline out. I cut the cats off and stuck a brass wedge into the fuel fill to allow for leaded gas nozzle to be put in so I could use leaded gas as it was cheaper. If you use a good grade of oil these days that’s all you need. I do use slick 50 every 100,000 miles it’s just a habit and I’m old enough now that I’m not going to change much. Thanks for the reply.

Mike
 

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I remember when they started fazing the leaded gasoline out. I cut the cats off and stuck a brass wedge into the fuel fill to allow for leaded gas nozzle to be put in so I could use leaded gas as it was cheaper. If you use a good grade of oil these days that’s all you need. I do use slick 50 every 100,000 miles it’s just a habit and I’m old enough now that I’m not going to change much. Thanks for the reply.

Mike
They still sell leaded gas in Arizona and Utah. You can buy 100 octane low leaded in Florida near the Okeechobee Swamp.
 

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Discussion Starter · #10 ·
They were still selling leaded gasoline the last time I was in the western portion of North Carolina and they have open carry laws that I like. It’s just too cold for me to live there full time, Florida blood in my veins.
 

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Mike, your a wimp, come up to Canada for a winter visit, I'll let you help me shovel the driveway after a storm and a cold north wind, haha.

But seriously, you would get use to it. My neighbour is from the middle East and he says his summer temps are over 50c (120f), he's been here 4, or 5, years and I think he is getting use to it.
 

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Discussion Starter · #12 ·
Mike, your a wimp, come up to Canada for a winter visit, I'll let you help me shovel the driveway after a storm and a cold north wind, haha.

But seriously, you would get use to it. My neighbour is from the middle East and he says his summer temps are over 50c (120f), he's been here 4, or 5, years and I think he is getting use to it.
Ray, I’m going to come to Canada for a summer visit once I retire. I’ve never liked cold weather even when I was younger. I have visited the Middle East more than once and I loved those temperatures. You’re right I’m a wimp when it comes to cold weather.

Mike
 

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Discussion Starter · #14 ·
Haha, Mike I was only teasing, we have the opposite problem, can't stand the heat.

But come to Canada, you will enjoy it here
Ray I know you were teasing me. To be honest I’ve only been in the snow twice in my life. I went to see my daughter in Michigan once, the first time was when I was young and I went to International Falls Minnesota for a six week shut down. I lasted 1 week and brought my butt back to Florida. I like your neighbors home temperature better than the cold. If this crazy winter doesn’t stop I’m moving south.
 

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It is a strange winter, we have had higher than normal temps and you are having colder than normal temps.
We were something like -11c yesterday and +11c and rain today.
Most winters we would see the ground frozen as much as 4 feet deep, this year it might be 4 inches deep, we have no snow, just bare trees and brown lawns
 

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Its been mild here since right after Chrismas. We had sub-freezing temps (0 - 10F) and wind before and during Chrismas, and then it 'warmed' up to 30's and 40's. Today has been the coldest since, with high of 33-34F (1C). Then this weekend and next week temps in the 40's. Yeah ha. Indiana nad Kentucky Winter. I'm sure that North Dakota temps will be coming. But this warm weather is nice. Thinking about getting my Camaro out of storage if we get enough rain to wash the salt off.
PS. Do they use a lot of salt in Canada too? Or do our Canadian friends know how to drive on frozen water?
 

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Discussion Starter · #19 ·
I’m moving to Florida after this winter, It’s been upside down. Cold where it’s supposed to be warm and warm where it’s supposed to be cold.
 

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Discussion Starter · #20 ·
Its been mild here since right after Chrismas. We had sub-freezing temps (0 - 10F) and wind before and during Chrismas, and then it 'warmed' up to 30's and 40's. Today has been the coldest since, with high of 33-34F (1C). Then this weekend and next week temps in the 40's. Yeah ha. Indiana nad Kentucky Winter. I'm sure that North Dakota temps will be coming. But this warm weather is nice. Thinking about getting my Camaro out of storage if we get enough rain to wash the salt off.
PS. Do they use a lot of salt in Canada too? Or do our Canadian friends know how to drive on frozen water?
In a little over 4 years I’m going to start doing exactly what your signature states, see America behind the wheel of my Chevy.
 
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