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Thread: Ouch! Cam Lobe Damaged

  1. #1
    Join Date
    Jun 2013
    Location
    N. California
    Posts
    36

    Default Ouch! Cam Lobe Damaged

    Looks like I get to deal with cam repair and replacement! I was aware of the noisy valvetrain when I purchased the car and here's the reason:


    The cam is a Web Camshaft grind and they were able to look up the specs from '03 when the engine was built. It was repaired once in '05. Here we go, down the rat hole! I'm hoping to have it in the mail to them this week for evaluation, repair, and suggestions on how stop this. I don't have the exact cam specs handy, but .400" lift and 244deg were mentioned during our phone conversation.

    I wanted a project...

    Andy
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  2. #2
    Join Date
    Feb 2009
    Location
    NYC
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    4,038

    Default

    As a person who knows all about camshafts melting down on dynos recently , you have to ask why it happened before you repair/replace.

    Why only one lobe and why that rather unusual damage? What did it hit?

    Since it is the second time it received damage does it make sense to drop in a brand new replacement? You can replicate original specs to avoid needing a retune and have peace of mind to know it is not weakened and potentially happen again.
    Mike
    2010 Caterham CSR with Cosworth 2.3 Duratec
    2018 Caterham 420R wit 2L Duratec 210hp at Donington UK
    1975 BMW CSL Group 4 (restoration - engine and dry sump install time)
    1977 Holden Torana "A9X" (awaiting restoration)
    1985 Holden Commodore Group A (restoration - engine rebuild)
    1982 Ferrari 400i (catching up on deferred maintenance)
    1965 Ford Mustang Fastback "Holman Moody"
    1992 Ford Escort RS Cosworth (fettling after long period of storage)
    1990 Range Rover 2 dr Classic

  3. #3
    Join Date
    May 2010
    Location
    Chicago
    Posts
    104

    Default

    Only one cam lobe, the rest are perfect. I some ways the damage looks like flaking, but in some ways impact damage. Do you know if it was a billet cam or was it welded up? I would try and find an independent opinion before you send it back to the manufacture. Do you have a local engine builder/ race shop. Show it to them and see what there is opinion is, use that and the manufacture opinion to come up with a cause.

    Graham

  4. #4
    Join Date
    Jun 2013
    Location
    N. California
    Posts
    36

    Default

    Mike,
    You're right, the big question is what caused it. These cams are welded and reground and there were signs of wear on a few other lobes, both intake and exhaust. The one in the photo is the worst example. The valve clearance was .016" so there was some material removed .

    As far as the cause Web suggested the possibility of incorrect spring rate or interference. There were also signs that the car sat a bit because some of the lobes showed signs of corrosion on the heels of the lobes. This could tie into the cold blooded nature of the engine's current cooling arrangement. Diagnosis is going to be tough without history on the engine...

    Any suggestions for a good valve spring compressor that will allow me to remove the springs while the head is on the engine?

    Andy

  5. #5
    Join Date
    Dec 2008
    Location
    Port Angeles, WA
    Posts
    239

    Default

    Quote Originally Posted by ashyers View Post
    Any suggestions for a good valve spring compressor that will allow me to remove the springs while the head is on the engine?
    Compressed air into the sparkplug hole will hold the valves closed while changing springs or seals--if you have good valve seats.

    What kind of oil were you running?


    Randall

  6. #6
    Join Date
    Jun 2013
    Location
    N. California
    Posts
    36

    Default

    Graham and Randall,
    Thanks for the responses.

    Graham, I think you were typing the same time I was! There's some further info in my post.

    Randall, as far as oil I believe the PO was running 5w-40 Motul. Do you have a recommendation for a valve spring compressor that works well on the Duratec?

    Andy

  7. #7
    Join Date
    May 2010
    Location
    Chicago
    Posts
    104

    Default

    Motul oil is as good as it gets, so that is not the issue. I think you just need to pull the head and get it checked out a set, head, springs and cams. I think it will be a false economy to do anything else. Someone might have cut the spring seats, the valve seats might be the problem, and you would never know. Another option is to just get a new head, get it build by a reputable shop and swap it over, that would be my plan of attach.

    Graham

  8. #8
    Join Date
    Feb 2009
    Location
    NYC
    Posts
    4,038

    Default

    As painful as it sounds, it is hard to argue against Graham's logic above since I suspect a past bodge is at work here and you may struggle to understand where they got sneaky.
    Mike
    2010 Caterham CSR with Cosworth 2.3 Duratec
    2018 Caterham 420R wit 2L Duratec 210hp at Donington UK
    1975 BMW CSL Group 4 (restoration - engine and dry sump install time)
    1977 Holden Torana "A9X" (awaiting restoration)
    1985 Holden Commodore Group A (restoration - engine rebuild)
    1982 Ferrari 400i (catching up on deferred maintenance)
    1965 Ford Mustang Fastback "Holman Moody"
    1992 Ford Escort RS Cosworth (fettling after long period of storage)
    1990 Range Rover 2 dr Classic

  9. #9
    Join Date
    Feb 2012
    Location
    Roswell GA
    Posts
    888

    Default

    There doesn't look like there is much metal missing BUT, it's still somewhere in the motor. Metal chips and shavings circulating in the motor is scary to me.
    Life happens while you're making other plans
    1995 Caterham Crossflow RHD
    1990 Miata
    2013 Mini (Her's)

  10. #10
    Join Date
    Nov 2007
    Location
    Ambler, PA
    Posts
    971

    Default

    Iím thinking your going to find the problem is deeper into the engine than your camshafts. Iíd pull the head off and get a better idea of why just one lobe is banged up.Something with that cylinder chamber is bent, stuck, what ever you would like to call it. I would also clean out the oil pan and maybe even replace the oil pump. Arenít these cars fun. Best of luck Sir..
    Superformance S1 # 47

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