Diesel oil.

[33 IMP]

I have heard that diesel oil has sufficient zinc in it for regular use in flat tappet engines. Does anyone know for a fact if this is true?
In a related question: does anyone know, at what oil grade rating the oil companies started removing the zinc? I have a couple of cases of sg rated racing oil, some sj racing, some sm racing.
I will shortly be breaking in a 440 with a purple shaft solid flat tappet cam. I'm planning on some diesel, some racing, and some Lucas break in additive, and then try to run diesel from there on after break in. I have a diesel pickup, and buy diesel oil every time there is a bargain available.
Otoh, I know the old racing oil has good zinc quantity, maybe just use that? Possible problem, it's straight 50 wt.

 

[Jerry Hall]

I use Valvoline 20-50 Racing Oil in all my old Mopars. Zinc was taken out of oil as it was the cause of catalytic converter failure so I've been told. It sounds reasonable but I never actually checked. I have never checked for zinc content in the Shell Rotella 15W-40 that I run in my Cummins diesel. For the new Hemi's I'm with the Mobile-1 0W-40 that's recommend.

 

[1967coronet]

My 383 lived on Rotella 15- 40 for several years. Last year the 67 got a 440 along with new comp cam ect. I used brad penn break in oil for the cam / lifter break in and 1st few miles.
Now its also back on rotella 15 - 40 but I now add a $9.00 bottle of lucas zinc additive at each oil change just for insurance. The lucas may not be needed I just like having it in there.

 

[steve340]

I read the anti wear additives have been removed from diesel oil also. There is plenty of info on the internet.
I believe SG is about the last rating of oil that was OK to run on flat tappet.
I always add extra ZDDP for the break in I am paranoid about losing cam lobes.
I destroyed one cam and plenty of people I know have also had failures.
I use Castrol Edge 20/50 for run in with additive and use just the Edge after break in.
No problems since I stared doing that.

 

[33 IMP]

I did a internet search and found that the zinc levels were mandated down for g4/sm rated oil. I checked three different brands of diesel in my garage, they were all rated (among about four other rating systems) s/n.
Looks like I'll have to use old oil and additive.

 

[The Rebel]

I use this and a high end restoration shop I've done business with recommended that I use this. I don't quite understand why people use diesel oil in a non diesel engine.

 

[beanhead]

Lots of folks have used the rotella over the years because it HAD good zddp content even after EPA started removing it from gas-engine oils(and it's cheap, maybe the bigger reason).. I tend to agree with 'the rebel' above though the detergent package has always been different and formulated specifically for diesels, guys will say they used it forever and ever with no problems but I've always stuck with oil made for gas engines..the problem is nowadays even the zddp in rotella has been reduced.

 

[Frank Mopar]

At the bottom of this read is a list of oils with zinc content

http://www.sccoa.com/forums/showthr...nds-offer-the-best-protection-***Good-read***

 

[wannadrag]

Brad Penn

 

[33 IMP]

@Frank Mopar, thanks for that!
I find it interesting that in his testing, the second highest rating for conventional oil is good old chevron delo diesel oil, that I have been buying when it's on sale at costco. Also very interesting about zddp additives making decent oil worse!?

 

[Frank Mopar]

Another interesting thing I see on the list is that some racing oils are not suitable for street use. So I found this.

https://www.enginelabs.com/tech-stories/racing-oil-vs-street-oil-know-the-differences/

 

[Ranger16]

In a related question: does anyone know, at what oil grade rating the oil companies started removing the zinc?

 

[33 IMP]

Wow,@Ranger16 , I guess my SG rated racing oil is REALLY old!
Gonna use it anyway, I'll bet the additive package is great for break in.

 

[BIGSHCLUNK]

I've run the VR-1 for years...... jus' sayn'

 

[Ranger16]

CompSyn had posted some info and zinc numbers a while back on Rotella T5 diesel oil in a related thread. It still has good Zinc & Phosphorous numbers as I recall. It's what I use. Perhaps he'll chime in again.

 

[Dipstick]

A lot of the charts and graphs concerning ZDDP content are many years old, I'd like to see a recent comparison of currently available oils.

 

[Jerry Hall]

A lot of the charts and graphs concerning ZDDP content are many years old, I'd like to see a recent comparison of currently available oils.

I'm just going to keep using the Valvoline VR1 racing oil. It seems to have tested good for street use as well and I have broken in a couple of cams with it and no additional additives. It works for me and that is what counts.

 

[khryslerkid]

Brad Penn

Called Penn Grade now. Same formula since when it was Kendall.

Oils formulated with the proper zinc for flat tappet cams do not require the additive. Doing so changes the formula and can do more harm than good.

 

[Ranger16]

A lot of the charts and graphs concerning ZDDP content are many years old, I'd like to see a recent comparison of currently available oils.

I've searched.......to no avail.

 

[Roger63]

I use rotella in my isx 15 liter because of the zinc levels. When it comes to Cummins the more zinc the better.