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Increasing numbers of flat tappet failures?

Home Forums Stay Dirty Lounge Technicians Only Increasing numbers of flat tappet failures?

This topic contains 4 replies, has 5 voices, and was last updated by Avatar Matt 1 year, 5 months ago.

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  • #885910

    Hey guys,

    I thought I would ask around the community and see if any one else has noticed an increasing number of wiped cam lobes and lifters on flat tappet vehicles lately. I’ve had a rash of customers in the past 6 months come in the shop with wiped cam lobes on stock vehicles. As far as I can tell these vehicles have been maintained well, with regular oil changes. Before this, the only vehicles I saw come in with this problem were guys with performance motors and stiff valve springs who did not break the motors in properly. I know the amount of Zinc and Phosphorous in motor oil has rapidly declined since the “old days” but I can’t seem to get a straight answer on exactly when the oil producers started reducing ZDDP in motor oil. Reduced ZDDP levels are the only thing I can attribute to these failures; I just thought it was weird that I have noticed so many in the past year. Anyways, what do you guys think? Thanks!

Viewing 4 replies - 1 through 4 (of 4 total)
  • Author
  • #887332
    Tyler Rau

    That’s why I run Joe Gibbs HR2 hot rod oil with High zinc in my 84 chevy. Just installed a new cam, break in was great and running this unless I go roller cam.

    Kenneth E Wilcox

    Flat tappet not so much, however I know for sure chrysler and Chevy have trouble with the Multiple displacement/cylinder deactivation lifters either collapsing or the rollers taking out the cams.

    David Lambie

    I see this type of failure on early
    2.0 fsi engines flat tappet for high
    pressure fuel pump. Intake cam has 4 lobes on the end. Destroys
    The Cam and tappet, similar fail
    pattern to a standard v8. Moly disulfide is a good additive, reasonable. Diesel oil non synthetic is a good solution for older engines, has better amounts of zddp and phosphorus. Never had problems until dexos, attribute most hard surface failures to lack of solid film lube, just my 2 cents


    Someone posted a detailed article from one of the camshaft manufacturers (Comp Cams) to a Mustang forum I once belonged to with all of the details about what was and wasn’t in modern oils and which additives and oils to run.

    When I built the 308 in my Mustang II I ran a Comp Cam and broke it in with Rotella 15w40 and their break-in additive, and have run the Rotella oil since without issue. The 302 I pulled out of it had pretty nasty cam wear from running an oil without enough ZDDP.

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