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Zinc Additive

Discussion in 'Early CJ-5 and CJ-6 Tech' started by Dauntless1971, Nov 28, 2018.

  1. Nov 28, 2018

    Dauntless1971 Member

    Bend, OR
    Oct 22, 2004
    I was just searching for a new camshaft and started reading about zinc is no longer added to oil. One must buy a zinc additive to add to your oil with each oil change. Or you run the risk of the camshaft going flat. Is this old news? Do any fellow Jeep owners add zinc to the oil in these ancient machines?
  2. Nov 28, 2018

    tarry99 Member Sponsor

    Northern California
    Oct 29, 2012
    New Camshaft and lifters?..........add a Zinc additive to the breakin oil........first 500-1000 miles...........not needed after that.
    timgr, Rick Whitson and Hellion like this.
  3. Nov 29, 2018

    PeteL Member Sponsor 2019 Sponsor

    Hills of NH
    Aug 3, 2003
    Older engines with flat lifters (not rollers) are recommended by many to have zinc with each oil change. I use ZDDP.
    70cj5134f likes this.
  4. Nov 29, 2018

    Chilly Active Member 2019 Sponsor

    Mar 12, 2007
    I’ve read the same thing while I look for a new cam. I think I’ll be using zinc after my rebuild. I’ll maybe need two or three oil changes a year. It won’t affect my lifestyle to add zinc, or use oil made for classic cars such as Brad Penn which still includes zinc.

    My lifters are concave in the original engine that I’m rebuilding. Now the Cyl bores are also well worn so not a surprise. Cheap insurance for a fresh rebuild with a new cam and lifters.
  5. Nov 29, 2018

    70cj5134f Member

    East Tn
    Aug 18, 2018
    In performance engines with higher than stock valve spring pressure, it is needed every oil change. In stock engine, once while breaking in the cam, is all I do, then I use diesel oil,
    After that, it has more anti wear additives than car oil. Rotella is my fave.
  6. Nov 29, 2018

    timgr Jeepin' Nerd Sponsor 2019 Sponsor

    Medford Mass USA
    Aug 10, 2003
    Lots of contradictory information about this on the internet.

    It's true that ZDDP and similar compounds have been removed from passenger car motor oils, since the metal in them damages catalytic convertors. Unlike our old engines with flat tappets, new cars have roller rockers that reduce loading on the camshaft.

    There is a significant difference in cam loading between a high-revving muscle car engine and the engines in our Jeeps. Probably you can run a conventional oil after the initial camshaft break-in, if you are running a factory camshaft at normal speeds. I use either Delo or Rotella diesel engine oil which is rated for either gasoline or diesel engines. Diesels have wrist pin loads that are similar to the flat tappet loads seen by our old engines. Valvoline Racing Oil is another option if you want an oil with plenty of ZDDP.

    Lots of discussion on the web - best oil for flat tappet engines - Bing
    tarry99 and Alan28 like this.
  7. Nov 29, 2018

    Alan28 Sponsor Sponsor

    Châtillon en...
    Oct 21, 2012
    I had set this question when I was working, to the manager of an oil factory working for army and aircraft. The answer was to use standard oil, not synthetic, not additives because some parts were sensitive. Better means not always good.
    In fact I cannot say anything, so don't read this post. Do additives like zinc in a liquid form help longevity?
    What is sure is that we must wait a little bit after starting to have oil hot to circulate well, and that if the engine is too hot the oil becomes like water.
  8. Nov 29, 2018
    mike starck

    mike starck Member Sponsor 2019 Sponsor

    Jun 22, 2006
    That is very common.Most older engines I have disassembeled have this dishing on the lifter bottom.This is from '60s and '70s way before any changes occurred in motor il formulas.Normal wear.The issue that has already been addressed is breakin period vs high valve spring pressure. The open spring pressure on a dauntless engine is just above a briggs and Stratton. Not a problem mike
    Last edited by a moderator: Nov 30, 2018
  9. Nov 29, 2018

    jayhawkclint ΜΟΛΩΝ ΛΑΒΕ Sponsor

    Oklahoma City, USA
    May 18, 2006
    I started using Rotella in my Dauntless before I sold it, great stuff.

    Started using it in my Cummins as soon as I bought my truck a few years back. Rotella keeps getting better. Currently running 0w-40 T6 (Rotella). It's the shiz.

    I bought a couple older Audi/VW cars for my teen driver's. Started using it in those, too. The older Audi/VW (circa 2001) still used a flat tappet in their DOHC, albeit very large contact area, I assume for reduced pressures. Not sure what the new models use, but there are "European Formula" oils that I suspect are just additive oils for this reason.
  10. Dec 1, 2018

    Oldiron90 New Member

    Colorado Springs, CO
    Oct 28, 2018
    I either use cheap parts store conventional oil and Lucas ZDDP or Comp Cams oil which already has a decent amount of Zinc.

    BG MOA is a great Zinc Additive. I used to used it in all of my engines. There is one Napa in town that carries it and I dont make it over there much so I haven't used it since about 2013. Great stuff though.

    I put Marvel Mystery Oil in my gas and my oil too though lol.
    Zooks likes this.
  11. Dec 2, 2018

    chipdom Member

    Nov 3, 2013
    I use Shell rotella T4 15w-40 in the Dauntless. I purchase from tractor supply in 2.5 gallon containers when on sale for 30 bucks.
    JB47 likes this.
  12. Dec 2, 2018
    Howard Eisenhauer

    Howard Eisenhauer Super Moderator Staff Member Sponsor

    Tantallon, Nova...
    Nov 22, 2003
    This was a *BIG* subject 10-15 years ago, eventually it settled out to using Rotella is a good idea. I use it in Tonk & our '62 beetle Putt.
  13. Dec 2, 2018
    3b a runnin

    3b a runnin Sponsor Sponsor

    Jan 11, 2015
    Another vote for Rotella. T4 10w30
  14. Dec 2, 2018

    tarry99 Member Sponsor

    Northern California
    Oct 29, 2012
    Years back when I ran many class 8 power units we used to buy bulk motor oil in 55 gal drums.....and at that point Chevron Delo series 100 and 400 seemed to be the industry standard.....the lesser 100 had a basic additive package and the 400 had allot more cleansing abilities , keeping in mind this was in the late 70's and 80s and electronic fuel injection had not yet found its way into class 8 truck motors so dirty oil and engine wear was a constant that was on my mind daily.........most of the engine wear problems were brought on by mechanical fuel injection over fueling the motors which washed down the cylinder walls and contaminated the oil much more quickly.........which brought on the need to roll in new rod & main bearings every 300k miles and re-sleeve cylinders at say 500k...........but since fuel is power and you need power to make money the tradeoff at the time was acceptable.

    In 1995 we invested in several new Peterbilts with the new Cummins N-14 electronic motors and a steep new learning curve was now staring me in the face.........power was more easily attainable and oil changes went from 5-7000k miles up to 20k miles.........and up until a few years ago some of those older trucks had clocked over a million and a half miles and had never had the pan or cylinder heads off....... short of changing injectors every 2-300k miles the new challenge now was just understanding all the electronic glitches that flashed trouble codes.

    In 2000 I switched over to Pennzoil products as I had a Racing deal with them and they were just about giving me oil for the Trucks.............many years later Shell Oil acquired Pennzoil and Shell decided that Racing was hardly that attractive so they cut back on the sponsorships........but Shell oil still made made me a good deal to supply all my other Lubrication needs in Trucking.....and during this process I went to the Shell oil labs in Martinez to see how the Rotella oil would match up with the old Penns 15-40w blends that had previously done us such a great job..........Amazing enough the lab analyticals on both products were exactly the same..................I asked the chemist how could that be?............and he stated that for years the auto manufactures along with the government had been working together to standardize the basic additive packages that goes into making all oil...................and although some manufacturers choose to advertise or lay claim they have a special additive , in most cases it's just advertising something they all have..........as he made it clear that the basic feed stocks are all the same it's just the packaging that changes..............now you can find some synthetic oils that have higher PPM levels of ZDDP aka Zinc.........but if you run those.......more than likely you'll eat your catalytic converter up in that vehicle.......

    And as far as early motors in our Jeeps during breakin periods with new camshafts & lifters buy a good ZDDP additive and run it with your regular oil for the first 500-1000 miles.....That alone will probably increase the ZDDP PPM to over 2000 ppm vs the norm of about 750 ppm.......Change oil often and watch the temperature , you'll be fine.
    Last edited: Dec 3, 2018
    Glenn, 3b a runnin and gunner like this.
  15. Dec 2, 2018

    Tom_Hartz Member Sponsor 2019 Sponsor

    North Carolina
    Apr 9, 2014

    This is what I run.
    CJMark likes this.
  16. Dec 4, 2018

    nickmil In mothballs. Sponsor

    Happy Valley, OR
    Sep 23, 2002
    Several years ago Jasper Engines sent out a TSB (Technical Service Bulletin) saying to use a zinc additive or an oil with zinc (ZDDP) as they had a huge problem with flat tappet cams going flat from people using oils without zinc. To a point they started including break-in oil with their rebuilt engines.
  17. Dec 5, 2018

    tarry99 Member Sponsor

    Northern California
    Oct 29, 2012
    Nick, In what I have found it's not really a question of usings oils without Zinc as most oils on the shelf today when looking at there spec's have a ZDDP additive package included....the real problem is the lower percentage they now include which is only several hundred parts per million (PPM) , Due solely to the known that ZDDP in higher percentages kills catalytic converters.......

    A pint of most ZDDP additives mixed with 4.5 qts of basic motor oil is said to raise the PPM's to about 2000..........which is double or at least 25% greater than most Racing oils that advertise high ZDDP levels.

    And since were mostly talking about our Jeeps and basic camshaft profiles with seat spring pressures of 90-120 lbs I find it hard to believe that a stock camshaft is having any issues that are not more closely related to the initial first 5 minutes of run time.........whereby if the camshaft & lifters were not properly & generously coated with a sticky assembly lube along with pre-oiling and priming the system , the parts were already hurt before the vehicle even hit the street!
    mike starck likes this.
  18. Dec 5, 2018
    TIm E

    TIm E Member Sponsor 2019 Sponsor

    NW Arkansas
    Mar 2, 2017
    My old school (and very meticulous) machine shop guy seems to echo what Tarry said. He indicated that the ZDDP additive is critical for initial start-up and break-in, but not really necessary after the first oil change.
    mike starck and tarry99 like this.
  19. Dec 5, 2018

    mickeykelley Active Member

    Republic of Texas
    Oct 10, 2015
    That's what my engine guy says too, then after break in he suggest use going to synthetic without adding the zinc or just a plain 30wt. and zinc not necessary.
    mike starck likes this.
  20. Dec 5, 2018

    71CJ54WD Sponsor Sponsor

    May 3, 2018
    We have hydraulic lifters not solid flat tappet lifters. Rotella or any quality oil will protect the engine. Solid lifter engines have adjustment on the valve train. My Cummins has solid lifters but still get diesel oil. Our V6 engines should live another 50 years without any zddp additive.
    mike starck likes this.

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