Z D D P

[1STMP]

Let's go back in time. The year 1977.
The example vehicle is a Jeep CJ7
equipped with a carburated 304 V-8.
Engine tolerances have not yet transitioned
to the tight ones experienced today.
Let's say the Jeeps' cat has been removed,
the engine is bored, heads decked, 4 bbl
intake installed along with some headers
a lumpy cam, and a high stall.
What makes this powerplant any different
from a 1968 monster 440 other than make
and legend? The internal tolerances would
be compatible, yet, one requires the use of
ZDDP, and the Jeep has been run without
this recommended additive for a number
of years, with zero internal engine failures
other than normal wear and tear.
If the lack of ZDDP is wiping out cams,
would not the Jeeps' cam suffer the same
fate.? Bear in mind that this was before
ZDDP was found to be detrimental to
cats.
Could pushing the limits on engine builds
truly be the cause of wiped out cams? ie...
increased spring pressures, etc.?

 

[diesel_lv]

The ZDDP is required at break-in of a flat tappet cam. After that, it's just added insurance but not a necessity.

 

[lemondana]

I would imagine, that back in 1977-the oils still had acceptable amounts of ZDDP in them.

 

[66Satellite47]

I would imagine, that back in 1977-the oils still had acceptable amounts of ZDDP in them.

IIRC '77 was about the time oil properties started to change. The ZDDP level was still a factor in friction wear.

 

[moparedtn]

1994 was the beginning of the phasing out of zinc from motor oils - turns out, it doesn't get along
well with emissions controls (catalytic convertors).

 

[Geoff 2]

The problem with wiped FT cams was never the oil. The oil companies saw a marketing opportunity & went for it...& the suckers are still coming....
The problem was lifter metallurgy & the radius on the lifter foot. Soft metal, no radius, wrong radius, radius not centered.
The ZDDP in oils gets 'used up' which is one of the reasons the oil needs to be replaced at regular intervals.

 

[1STMP]

IIRC '77 was about the time oil properties started to change. The ZDDP level was still a factor in friction wear.

Then please explain why this motor has
survived for 160,000 miles (no catastrophic
cam or lifter failure) after spending it's entire
rebuilt life on oils with reduced levels of
ZDDP. Not trying to be contrary here, but
something just ain't adding up.
We've got a motor that required ZDDP
impregnated oils now running perfectly
fine without since 1982.

 

[1STMP]

The problem with wiped FT cams was never the oil. The oil companies saw a marketing opportunity & went for it...& the suckers are still coming....
The problem was lifter metallurgy & the radius on the lifter foot. Soft metal, no radius, wrong radius, radius not centered.
The ZDDP in oils gets 'used up' which is one of the reasons the oil needs to be replaced at regular intervals.

I'm intending to agree. Lack of engineering
practices of old are not being adhered to.
Per today's standards, this engine should have
died long ago.

 

[1STMP]

I would imagine, that back in 1977-the oils still had acceptable amounts of ZDDP in them.

Then why has this motor survived 100,000
+ miles with reduced levels of the magic
potion? It's run close to 35 years on a motor
once dependant, and now does fine without.

 

[1967coronet]

ZDDP, yes or no ?
GREEN BEARINGS, yes or no ?
Is it luck ? Is it science ?
Who knows ? All I can say is I'm sticking with tapered axle bearings and using zddp.
Cheap insurance both ways.

 

[Wietse]

It was used in high content in break-in oil and after it was not a specific requirement, just had to follow the recommended oil grade and specifications.
For sure ZDDP becomes more important as a continues protection factor if the engine is modified and faces increased spring pressures, faster lift ratio's, etc.
As the engine specs you mentioned on the 304 it does not seem to be something extreme, for all we know a set of stiffer springs could have wiped the cam out 50K miles ago. (or.... what would have happened if a lighter oil viscosity was used?)
I think it all comes down to the force applied (lbs/sq. inch) which is mainly determined by the valve springs, the cam and lifter will have a limit with a given oil viscosity before pushing through the oil film and metal-to-metal contact will occur.
Adding stiffer springs are more likely to push through the oil film, therefore the ZDDP will add the needed protection if/where the oil itself cannot do the job.
Now days, a lot of people have used the aftermarket options as bigger cams and heavier springs, which I believe it's survival will depend on the ZDDP as an additional lubrication.
Even modern cams and lifters, including the best brands money can buy still get wiped out without proper lubrication, the design of a flat tappet cam is harsh to any steel grade.
I don't think you would succeed in finding someone here to give up their ZDDP oil and throw in some modern type.
It's being an added cheap insurance for sure and I would not be willing to give that up and find myself removing a damaged camshaft some time later.

 

[Outlawd]

Who knows ? All I can say is I'm sticking with tapered axle bearings and using zddp

Yep. I've got a **** ton of time, blood, sweat, and tears in my last 440 build and zddp is used in every oil change. I got over 17 grand in the motor and Lucas Oil Zink additive is $18.00 a pint, I would pay $100 for it if I had to.

 

[moparedtn]

I don't think you would succeed in finding someone here to give up their ZDDP oil and throw in some modern type.

I did that once, not a lot of years ago to an established 440 engine - "synthetic is best" I thought, since I've always
run it in all the modern-era Mopars we've owned (including 2 now).
Well....that 440 wiped cam lobes in short order. Only took about a hundred miles.
One of the lifters actually developed a hole on the bottom.
Lesson learned, after a LOT of research....

Lookit, it's illogical to assume that just because someone is very fortunate with a particular engine in a
particular situation that whatever they experience would therefore mean EVERYONE will experience the
same good luck - because they aren't going to.
The need for zinc (don't forget phosphorus as well!) in oil for engines designed prior to 1994 is well
established science - there's literally tons of technical papers written about it, not to mention the
reams of testimonies from folks all over the planet.
More folks are going to experience bad things if they decide not to use it, it's just that simple.

The current problem with replacement parts is also well known, ESPECIALLY with lifters and/or cams.
Quality has gone in the shitter and even the honest dealers will own up to it if pressed.
You couple lower quality parts with neglecting to use zinc-rich oil and you're begging for disaster...

 

[69L48Z27]

Valve spring pressure plays a big part. Also good clean oil supply goes a long way. I only have one old engine I purposely run VR1 in and that’s due to cam profile and increased spring pressure. Anything with stock springs and cam profile gets a CK4 rated oil.

 

[BB BELLA]

the last oil test published I read showed no benefit to zinc. the 15/40 T6 which I like and use and supposedly higher in zinc was way down the list!
I'll see if I can find and post the article it's a long read with most of the current oils we know tested! maybe you guys can find fault with the tests!
i remember the quaker high mileage oil got a great reading and I was thinking just a marketing gimmick!

 

[Nate S]

Then why has this motor survived 100,000
+ miles with reduced levels of the magic
potion? It's run close to 35 years on a motor
once dependant, and now does fine without.

There’s a difference between break in and ongoing running. Also a difference between high lift and stiff springs and a stock 304.

Metals have become better in general with exceptions in China sometimes. These cams aren’t mainstream any more, expertise has gone down and we’re generations away from the engineers who designed them initially and learned all the lessons the first time. The ZDDP was put in there for a reason way back when. The oil needed to work in all cars under all circumstances, not just an already broken in 304.

 

[Wietse]

Interesting read. (from 2012)

https://www.speed-talk.com/forum/viewtopic.php?t=33547

 

[BB BELLA]

that's an excerpt from the article I mentioned!

 

[Wietse]

that's an excerpt from the article I mentioned!

http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/1028884-oil-test-zddp.html

 

[BB BELLA]

https://540ratblog.wordpress.com/
the original!