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Thread: Cam flat brand new 50 miles ???

  1. #1
    Senior Member DYNO OPERATOR bixblk's Avatar
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    Cam flat brand new 50 miles ???

    Got another one of these cam going flat with less than 50 miles on them. My buddies solid flat tappet Lunati cam, BBC 427, cam lube used very generoisly, careful breakin' , proper spring tension.High quality oil.
    This has come up a few time recently.As it has in the past, We get alot of different answers about why, some say steel quality,some say improper break in, some say it is the lack of the oil to lubricate, some say spring pressures. Maybe some times this is true ....but in this case I think all waas done properly.
    Wha are you guys feelings on this
    Interested. Also do you think Lunati will be open to talking to him ?
    Jeff

  2. #2
    Senior Member MASTER BUILDER
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    What was your valve spring seat pressure, and what is your open pressure.
    Also what oil did you use ?

    You can talk to Jeff over at lunati, Just ask for him.
    Competition Engines & Hardcore Engine Parts
    www.cnc-motorsports.com
    info@cnc-motorsports.com

  3. #3
    Senior Member DYNO OPERATOR bixblk's Avatar
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    BBC 427 flat cam

    His buddy did the motor ,and I do not know the valve spring pressures. The guy that built the BBC is extemely solid,
    I am pretty sure he did use castrol 20/50 oil
    Thanks I passed the info along to him about the contact person to talk at Lunati

  4. #4
    Senior Member DYNO OPERATOR
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    cam flat

    I have only had 1 cam do that and it was an error on my part.

    Comp Cams replaced the cam and lifters before i discovered the real problem. Luckily I did see it before wasteing another cam.

    When I installed the rear cam bearing "freeze" plug, I accidently mushroomed it in slightly. This pushed the cam just far enough forward that the lifters were centered on the cam and did not spin as they should while running. Looking down the lifter bore in the block the cam should NOT be centered with the bore.

  5. #5
    Senior Member DYNO OPERATOR
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    Not sure if Castrol contains Zinc but it's an absolute must on a flat tappet cam. Not only during break-in, but continually every oil change. Something to look in to. JMO

    TS1955

  6. #6
    Senior Member RACING JUNKIE
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    I think anybody that has ever built a motor has wasted a flat tappet cam, it happens but in your buddies defense it seems to be happening more now than ever.
    Alot say it has everything to do with the removal of the zinc and other antiwear agents they cut back in oils over the years due to EPA restrictions, maybe thats the culprit, some say the cam blanks aren't what they used to be, cores softer, cheaply made lifters etc, I dunno, it might be a combination of the two.

    I do know, when I build a flat tappet cam motor or any motor for that matter, I pay attention to the lifter bores, they need to be smooth as a baby's ass IMO, sometimes when you get the block back from machining it will start to rust up with a quickness, the lifter bore is no exception.
    I immediately clean and lube them, then check to make sure the lifter spins freely in each bore and with zero bind.
    I will check every bore and every lifter to make certain of this, if any are sticky, I'll use very fine wet sand paper (600-1000grit) in the bores, then clean and re-lube generously with motor oil.

    My 2 cents>Cp
    ***IN GOD WE TRUST***

  7. #7
    Senior Member DYNO OPERATOR bixblk's Avatar
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    great comments

    Thanks guys, very good comments.
    I think it is happening more than before. I am giulty of not paying attention to the lifter bore holes as I assume they are good. But I do spin the lifter as a habit.
    Any way i am going to talk to my buddy and see what the motor builder thinks. Again thanks.....To Be Honest This has been a bad year with breakage for me and running buddies.Hope next year will be better.

  8. #8
    Senior Member RACING JUNKIE
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    This is why I pretty much stopped fooling with flat tappets. I put one in my dad's car this summer.I bought a case of comp cams break in oil. what he runs in it. He rarely drives it so he just uses that since it is loaded with zinc. I still don't know if that's a good idea or not. Anyway, I have never had one go flat and I used to run them...and I never broke them in properly either.I Just started it up, set the timing and idle etc and forgot about it. zero problems.

    Now after reading online the last few years about the problems that people smarter than me have, I'm afraid to mess with them...I just run solid roller in my race car and a hyd roller in my chevelle.

  9. #9
    Senior Member DYNO OPERATOR bixblk's Avatar
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    Cam flat

    I am very interested in see what my buddies motor guy says.
    "zero problems" ,,,,boy have heard that before. Just messing with ya"
    Jeff

  10. #10
    Senior Member RACING JUNKIE
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    Re: Cam flat

    Quote Originally Posted by bixblk
    I am very interested in see what my buddies motor guy says.
    "zero problems" ,,,,boy have heard that before. Just messing with ya"
    Jeff
    Took me a second, but I got it.

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