Zinc oil additives

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I am old school so for 20+ years I have been using STP oil treatment which contains zinc to every oil change and never have I had any issues in my current 340 and my previous 440 R/T
 
I lost a cam that was running fine for years.....not long after I switched to this oil:

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Seems like a winner, right? Synthetic, extra ZDDP ....

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Uhhh....

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SN is a VERY high detergent oil.
THIS is bad because the detergent wipes away the ZDDP. What sense does this make? Add ZDDP to the oil but also add in detergents that don't allow it to cling and protect?

What has changed in the last 20 years?
Yeah, the oil has changed but there are oils that still protect.
Bigger cams, stiffer valvesprings are a factor but what about the camshaft and lifters?
Testing has shown that most aftermarket cams and lifters have similar hardness as stuff from the 70s so it may not be a matter of metal durability.
What is left to blame?
Some claim that the cams don't have enough taper and the lifters don't have enough crown. These two things MUST exist to allow the lifters to spin. A lifter that does not spin will fail.
The whole reason detergents were added, IMO was because people either would not change their oil, ir did it way less frequently than they should. I think you could run the old single weight non detergent oil as long as there was sufficient ZDDP for the type of lifter you run. That's my opinion and I'm stickin to it.
 
I am old school so for 20+ years I have been using STP oil treatment which contains zinc to every oil change and never have I had any issues in my current 340 and my previous 440 R/T
I agree, it does. HOWEVER, be very aware of the store brand STP oil treatment. READ the label and you will find out that most all store brands do not contain any ZDDP at all. I know for a fact the Oreilly brand does not. So use the real thing.
 
Running same oil with Lucas, solid flat tappet. I'll bet the **** mixes. "Sit on the bottom"?? Then it'll be 1st to the pump and 1st to the top....
Right. I always thought the "It doesn't mix" theory was bunk anyway. Those chemists know what the hell they're doing!
 
The whole reason detergents were added, IMO was because people either would not change their oil, ir did it way less frequently than they should. I think you could run the old single weight non detergent oil as long as there was sufficient ZDDP for the type of lifter you run. That's my opinion and I'm stickin to it.
Yep.
What does detergent in motor oil do?



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Detergent oils have enhanced additive packages blending in them to prevent rust, break down engine sludge and stabilize acids to prolong oil life. With a newer engine or an engine that has been running on a detergent oil for years this is the right choice, it keeps your engine cleaner and running smoothly.Jan 20, 2020
 
The whole reason detergents were added, IMO was because people either would not change their oil, ir did it way less frequently than they should. I think you could run the old single weight non detergent oil as long as there was sufficient ZDDP for the type of lifter you run. That's my opinion and I'm stickin to it.

They use detergents and dispersants (among other things) because no engine has ever run on “new” oil. All engines run on used oil unless you change it every 15 minutes of run time.
 
Driven GP1. That’s what my builder said to use. (IMM Engines) $10.95 qt from summit, if ordered before 7pm it’s here tomorrow.

But I’m sure there are other great oils as well.
 
I just crush up a few of these at oil change time, line it up on the inner fender, pull a vacuum hose and let her eat.

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I agree, it does. HOWEVER, be very aware of the store brand STP oil treatment. READ the label and you will find out that most all store brands do not contain any ZDDP at all. I know for a fact the Oreilly brand does not. So use the real thing.
Thats what I had heard also so every time I buy a bottle I read to make sure it does indeed contain zinc.
 
I was talking to an oil rep one day and he was totally against using zinc additives that was not formulated in the oil. He basically said that if wasn't in the oil, then it probably wouldn't mix in the oil and may just lay in the bottom of the pan. He wasn't selling any special oil to me just a conversation about zinc in oils vs additives.
I find it impossible to believe that the additives would just sit in the bottom of the pan.
The sump is supposed to sit on the bottom of the pan and suck out all of the oil mixture and send it through the oil galleries of the engine and then it drains back to the pan and is always recycled and the additives are in suspension.
Now a different argument to make would be that the detergents wash the Zinc additives off the cam almost right away, so they have little to no affect in preserving the cam and lifters, which is more believable to me...
 
I find it impossible to believe that the additives would just sit in the bottom of the pan.
The sump is supposed to sit on the bottom of the pan and suck out all of the oil mixture and send it through the oil galleries of the engine and then it drains back to the pan and is always recycled and the additives are in suspension.
Now a different argument to make would be that the detergents wash the Zinc additives off the cam almost right away, so they have little to no affect in preserving the cam and lifters, which is more believable to me...
If additives just sit in the bottom of the pan, then that means every single oil pan has additives sitting in the bottom, because every single oil out there has additive packages as part of the oil. Do they separate? Hell no.
 
I use Castrol 10w40 in my 318 with a bottle of STP that has zinc in it in my73 valiant with a Purolator filter my dad used to use it in his satellite back in the70s , never had any problems. when I used 15w40 in my 318 duster I had to drain it out the lifters were going tapity tapity tap tap.. I went back to 10w40 Castrol with STP.
 
I have a 2005 Cummings diesel that I use Rotela, 15 - 40, sense new (200,000 miles, now), I was wanting to use the same in my 69' 340 Dart, but was told (don't remember who) that it was not good for my flat tappet cam. I do add an additive, but would rather just use the Rotela for both. Any input?
 
I have a 2005 Cummings diesel that I use Rotela, 15 - 40, sense new (200,000 miles, now), I was wanting to use the same in my 69' 340 Dart, but was told (don't remember who) that it was not good for my flat tappet cam. I do add an additive, but would rather just use the Rotela for both. Any input?
I myself had a bad experience with the rotella in my duster when I had it. soon as I fired it up lifter noises scared me and the oil pressure went up to 80pounds I got afraid that I was going to blow the seals out the engine so drained it out and used 5 quarts of Castrol 10w40 with a bottle of STP and it quieted down I know everyone uses rotella 15w40 and have no problems . I'm just Leary about using it I have my 318 1973 valiant and I use Valvoline 10w40 with STP additive and it works but that engine is all original never been rebuilt what works for me may not work on others I live in north Carolina so I use 10w 40 if I was in Florida I would use 10w 50 . if I was in NY I would use 10w30 because of temperature and altitude this is just my experience of what I've experienced
 
I have run zinc oil additives in my older engines for years.
How do you guys feel about zinc additives?
That is a delicate subject. Most on the shelf oils are formulated for catalytic converter autos these days. The ZDDP kills converters so the OEMs pushed oil companies to remove most of the harmful additives, which necessitated the swith to roller cams.
Oil formulation is a complex subject. Do you know how much of what is in the oil? Do you know what is beneficial and what is not? Best to purchase an oil formulated for flat tappet followers. You need about 1,200ppm of zinc to protect the cam and lifters. Too much may also be harmful. That additive bottle, do you put 1/4, 1/2 or all of it in?
 
^^^^ This! ^^^^
I myself had a bad experience with the rotella in my duster when I had it. soon as I fired it up lifter noises scared me and the oil pressure went up to 80pounds I got afraid that I was going to blow the seals out the engine so drained it out and used 5 quarts of Castrol 10w40 with a bottle of STP and it quieted down I know everyone uses rotella 15w40 and have no problems . I'm just Leary about using it I have my 318 1973 valiant and I use Valvoline 10w40 with STP additive and it works but that engine is all original never been rebuilt what works for me may not work on others I live in north Carolina so I use 10w 40 if I was in Florida I would use 10w 50 . if I was in NY I would use 10w30 because of temperature and altitude this is just my experience of what I've experienced
This! Yeah, I was wondering why My Oil Pressure was Soo damn High! Stock Pump at Idle is over 70 psi!
I think I might ditch the Rotella T this Year and Switch to a Regular Valvoline instead...

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I find it impossible to believe that the additives would just sit in the bottom of the pan.
The sump is supposed to sit on the bottom of the pan and suck out all of the oil mixture and send it through the oil galleries of the engine and then it drains back to the pan and is always recycled and the additives are in suspension.
Now a different argument to make would be that the detergents wash the Zinc additives off the cam almost right away, so they have little to no affect in preserving the cam and lifters, which is more believable to me...
Additives in oil should not sit on the bottom of the pan. There is a terrific amount of turbulence in there. Now how well it mixes is debatable. Detergent and dispersant additives help keep byproducts of combustion in suspension so the oil filter can trap them. Poorly maintained engines show up easily on teardown with sludge coating everything not in contact with another part. Older engines like from the 50's that used nondetergent oils generally have a coating of sludge 1/4" to 1/2" thick on the heads under the valve covers, in the lifter valley and inside the crankcase.
 
Flat tappet cam: VR-1 10w-30 is my go to if I have some valve spring pressure. If it has the weak stock valve springs of a stock engine, and if it's already been broken in with some miles on it, I will just use Rotella T4.
  • Yes, i have used different types of zinc additives and they have worked as well, including ZDDPMAXX
I'm surprised at the silence by popular 'Hot-Rod' type magazines on this topic for flat-tappet type original engines. I'd like to know from an unbiased source, if there is a mixing problem that makes additives ineffective or if there is a vested economic interest with this claim, with adding additives, too.
 
That is a delicate subject. Most on the shelf oils are formulated for catalytic converter autos these days. The ZDDP kills converters so the OEMs pushed oil companies to remove most of the harmful additives, which necessitated the swith to roller cams.
Oil formulation is a complex subject. Do you know how much of what is in the oil? Do you know what is beneficial and what is not? Best to purchase an oil formulated for flat tappet followers. You need about 1,200ppm of zinc to protect the cam and lifters. Too much may also be harmful. That additive bottle, do you put 1/4, 1/2 or all of it in?

Once again, for the umpteenth time ALL engine oils have some form of phosphated zinc in it. ALL of them.

It can’t be engine oil without it. It wasn’t all removed it was reduced.

Since that particular additive is a consumable it gets used up. With less to start with you run out (or don’t have enough left) sooner and then you get a failure.

Phosphated zinc is a power eater. When you add more than you need, power drops. Quite a bit.

When an oil is blended the tribologist takes into account how each component affect the others in either a positive or negative way. Because any component brings its own chemistry to do a certain job but it can (and will) affect how the other components do their job.

If the oil someone is using is so bad that it needs some additive its time to buy a better oil.

Adding a zinc product is a bad idea because no one on here knows exactly what the outcome will be when it’s done. You can add something and it may make the dispersant package less effective. Or it can make the detergent package less effective.

Unless someone has the ability to analyze the original oil and then analyze it again with the additive it can’t be predicted or known what the outcome will be unless it has been tested before.

I know the myth that additives fall out of the oil. I’ve only seen that happen in one situation. The issue is what happens when someone adds something to an oil that the tribologist who built the oil never intended to use.

Buy the right oil the first time and leave the additives on the shelf for the suckers.
 
Take post 48 and bookmark it. Or make a sticky. Or do what is needed so when the same question arises in a few weeks it can be referred to here.
 
Take post 48 and bookmark it. Or make a sticky. Or do what is needed so when the same question arises in a few weeks it can be referred to here.
Yeah, he's an infected dog's butthole sometimes, but when he's right he's right. lol
 
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