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Thread: Bad Camshaft broken cam guide

  1. #1
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    Bad Camshaft broken cam guide

    Well I purchased FFR cobra MKIII with a 347 only 8K miles. This engine has EFI with Mass Air Flo ECU.The lifter guide broke don’t know where the piece is.
    Can I drop the oil pan or where can I look for piece
    How do I know which Camshaft should I order
    How can I be reassured there isn’t something that would make this reoccur
    Do I need to pull the engine or can I install new cam with engine installed. Concerned with front cross bar maybe blocking.
    How do I determine Camshaft
    Please help see photos
    Attached Images Attached Images

  2. #2
    Senior Member gbranham's Avatar
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    I'd start by dropping the oil pan and looking for the broken piece of the dog bone, yes. Yes, you can swap the camshaft with the engine in the car. I've done it on a MkIII with a 408. Plenty of room. Can't tell you what cam to purchase. Not enough info. Need more info on heads, rotating assembly, pushrods, rocker ratio, etc.

    Greg
    Built an early MkIII years ago, sold years ago. Back after 18 years to build a MkIV
    Build Thread Here Partners: Summit Racing, LMR, Breeze, Forte's Parts, Speedhut, Amazon
    MkIV Complete Kit Ordered 4/18/23, Delivered 7/11/23, Boss 427W, Edelbrock Pro Flo 4, TKX (.68 5th), IRS, Wilwood Brakes, 18" Halibrands, Toyo R888R Tires, Custom Speedhut Gauges

  3. #3
    bobl's Avatar
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    It looks like that lifter is dropped down way too low. I'm guessing it broke and dropped below the guide bar and then broke it when it came back up. Most likely the cam is ruined and you'll need to replace all the lifters, guides and retainer. Then you need to figure out what other carnage occurred.
    Mk IV Roadster, 347/516 HP, 8 stack injection, Holley HP ECU, Astro Performance T5, 3-Link 4.10 gears, A/C, PS, PB Purchased 08/2015, Graduated 02/2017

  4. #4

    Steve >> aka: GoDadGo
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    Quote Originally Posted by bobl View Post
    I'm guessing it broke and dropped below the guide bar and then broke it when it came back up.
    Did the lifter retainer plate back out or loosen allowing the dog bone retainer pop up and get hung on the lifter?
    Last edited by GoDadGo; 09-08-2024 at 10:40 AM.

  5. #5
    bobl's Avatar
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    I.ve seen them break because a rocker nut backed off or broke, or possibly a pushrod failure and the lifter just hammers away with no load. It's hard to tell the cause sometimes. Which failed first. A picture of all the parts would help.
    Mk IV Roadster, 347/516 HP, 8 stack injection, Holley HP ECU, Astro Performance T5, 3-Link 4.10 gears, A/C, PS, PB Purchased 08/2015, Graduated 02/2017

  6. #6
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    Quote Originally Posted by GoDadGo View Post
    Did the lifter retainer plate back out or loosen allowing the dog bone retainer pop up and get hung on the lifter?
    No the retainer was in place it appears the the dog bone broke cheap metal than the lifter turned and seized. It dropped only becuase it turned it back in place to pull it out but it slid down.

    Can anyone help me determine the cam to replace like for like or select a better option.
    How do I determine.
    My springs are good it was just a lifter seized the screwed the cam probably wore it down.

    Current Head AFR 1420
    Manufacturer's Part Number:
    1420
    Part Type:
    Cylinder Heads
    Product Line:
    AFR 185cc SBF Renegade 20 Degree Street Heads
    Summit Racing Part Number:
    AFR-1420
    Combustion Chamber Volume (cc):
    72
    Intake Runner Volume (cc):
    185cc
    Exhaust Runner Volume (cc):
    68cc
    Cylinder Head Style:
    Assembled
    Cylinder Head Material:
    Cast aluminum
    Camshaft Style:
    Hydraulic roller
    Intake Port Shape:
    Rectangular
    Intake Valve Diameter (in.):
    2.020 in.
    CNC-Machined Combustion Chamber:
    Yes
    CNC-Machined Intake Runner:
    Yes
    CNC-Machined Exhaust Runner:
    Yes
    Combustion Chamber Style:
    Heart
    Intake Port Location:
    Standard
    Last edited by CobraKai716; 09-08-2024 at 12:50 PM.

  7. #7
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    Need help for Cam selection

    No the retainer was in place it appears the the dog bone broke cheap metal than the lifter turned and seized. It dropped only becuase it turned it back in place to pull it out but it slid down.

    Can anyone help me determine the cam to replace like for like or select a better option.
    How do I determine.
    My springs are good it was just a lifter seized the screwed the cam probably wore it down.

    Current Head AFR 1420
    Manufacturer's Part Number:
    1420
    Part Type:
    Cylinder Heads
    Product Line:
    AFR 185cc SBF Renegade 20 Degree Street Heads
    Summit Racing Part Number:
    AFR-1420
    Combustion Chamber Volume (cc):
    72
    Intake Runner Volume (cc):
    185cc
    Exhaust Runner Volume (cc):
    68cc
    Cylinder Head Style:
    Assembled
    Cylinder Head Material:
    Cast aluminum
    Camshaft Style:
    Hydraulic roller
    Intake Port Shape:
    Rectangular
    Intake Valve Diameter (in.):
    2.020 in.
    CNC-Machined Combustion Chamber:
    Yes
    CNC-Machined Intake Runner:
    Yes
    CNC-Machined Exhaust Runner:
    Yes
    Combustion Chamber Style:
    Heart
    Intake Port Location:
    Standard

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