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  1. #1
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    N52, N54 and N55 EXHAUST Camshafts

    So my interest has been the N52/N55/S55 Valvetronic Intake system and finding a way to increase the intake valve lift on these engines by using my MILVs. (+1mm additional intake valve lift and 2-3* increased duration)

    So the next question is, What about the exhaust cam?

    What I have found out when looking at the Exhaust cam of the N52, N54, N55 and S55 engines.
    -all use the same exhaust camshaft clamshell/bearing ledge
    -all use the same hydraulic lifters
    -all use the same rocker arms, 1.66:1 ratio
    -the N55 and S55 share the same exhaust cam

    What is the actual specifications of these cams? Cam lift and duration?
    Will they interchange? What are, if any, the physical differences?

    I bought 4 different exhaust camshafts that I am sending out to be 'Cam Doctored'.
    Used N52, N54, N55 and a new N52 cam from Russia, reportable an OEM supplier.

    Any guesses as to the specs and differences?
    You would think that the turbo engines would have more exhaust cam lift and duration for the higher power output. Or maybe the N/A N52 will have more exhaust cam lift and duration due to it's higher redline.

    My simple HF digital caliper shows that all 4 camshafts have the same 0.23" cam lift = 9.698mm with the 1.66:1 rocker arms.
    Close enough to BMW's 9.7mm reported value.

    Can I get an additional +1mm exhaust valve lift and 2-3* duration from the Exhaust Cam?
    Is there enough metal on the lobes for a re-grind?

    Any thoughts or comments?
    MILVs- +1mm Increase Intake Valve Lift for N52, N55, S55, N20 Engines
    http://www.bimmerboost.com/showthrea...ift-more-power
    www.bimmerMILVs.com
    Coming soon: +1mm lift Exhaust cam N52 and N55

  2. #2
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    Click here to enlarge Originally Posted by CobraMarty Click here to enlarge
    I bought 4 different exhaust camshafts that I am sending out to be 'Cam Doctored'.
    Where did you send them to?

    This is pretty darn interesting though. Want to see if there is any major difference if any among them.
    Click here to enlarge4 WEEKS LEFT

    BOOSTADDICT DRAG DAY MAY 5th

    LIMITED SPOTS AVAILABLE

  3. #3
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    Jun 2015
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    1 out of 1 members liked this post. Yes Reputation No
    It was tough to find an independent shop that has a 'Cam Doctor' and would even do this work.

    They are going out to SRE in AZ.

    Sure there are Schrick and CAT cams and we know those numbers for the N54, but what is the stock N54 exhaust cam specs, What was the starting point?
    And more importantly, What are the stock N52 and N55/S55 exhaust cams? You can't do a re-grind without knowing where you are starting at.
    MILVs- +1mm Increase Intake Valve Lift for N52, N55, S55, N20 Engines
    http://www.bimmerboost.com/showthrea...ift-more-power
    www.bimmerMILVs.com
    Coming soon: +1mm lift Exhaust cam N52 and N55

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