Big cam, stiffer valve springs needed?

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  • CorvallisBMW
    Long Schlong Longhammer
    • Feb 2005
    • 13039

    #1

    Big cam, stiffer valve springs needed?

    I'm looking at getting the IE 284 duration cam. IE also makes a set of dual valve springs that they say are recommended with any high-lift cam. Does this seem accurate? 284 doesn't seem too exotic and I'd love to save the $400 it would cost to buy new springs and retainers.
  • Ryann
    No R3VLimiter
    • Mar 2010
    • 3350

    #2
    Do a lot of high RPM driving? What kind of shape is your current valve train in? What's the cam's lift spec over stock?

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    • CorvallisBMW
      Long Schlong Longhammer
      • Feb 2005
      • 13039

      #3
      Originally posted by Ryann
      Do a lot of high RPM driving? What kind of shape is your current valve train in? What's the cam's lift spec over stock?
      -Not really, it's just a cruiser
      -Clean enough to eat off of
      -Don't know, IE doesn't publish details

      Comment

      • Ryann
        No R3VLimiter
        • Mar 2010
        • 3350

        #4
        Originally posted by CorvallisBMW
        -Not really, it's just a cruiser
        -Clean enough to eat off of
        -Don't know, IE doesn't publish details
        Without knowing the lift specs it's tough to say how aggressive the grind is over stock, but unless you're planning on flogging the car you should be fine with stock springs.

        On the other hand why spend the money to shift your power band Northward in a cruiser?

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        • Bearmw
          E30 Fanatic
          • Aug 2010
          • 1323

          #5
          I'd call IE and talk to Jeff. I have a cam that has .440 lift at intake valve and .430 lift at exhaust valve and advertised duration of 280 intake and 278 exhaust with new B-35 springs with no problem.
          Never argue with stupid people, they will drag you down to their level and beat you with experience. -Mark Twain

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          • Good & Tight
            Forum Sponsor
            • Apr 2004
            • 2057

            #6
            I would contact Paul Burke about a cam before buying a regrind from IE. Info@bmwpowerparts.com.
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            • LJ851
              R3V OG
              • Nov 2010
              • 7918

              #7
              Originally posted by good & tight
              i would contact paul burke about a cam before buying a regrind from ie. info@bmwpowerparts.com.

              yes.
              Lorin


              Originally posted by slammin.e28
              The M30 is God's engine.

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              • ZM Blue Devil
                Forum Sponsor
                • Dec 2006
                • 13836

                #8
                yes you will need stiffer springs
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                • SkiFree
                  R3VLimited
                  • Jun 2011
                  • 2766

                  #9
                  Think we talked yesterday over the phone?
                  Last edited by SkiFree; 03-07-2012, 10:13 AM.
                  ADAMS Autosport

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                  • Lurker27
                    E30 Modder
                    • Jul 2007
                    • 821

                    #10
                    I was told that you won't need new springs if you have an m30b35 head, which already has dual valve springs. You WILL need oversize adjusters
                    '89 335is +turbo

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                    • Bearmw
                      E30 Fanatic
                      • Aug 2010
                      • 1323

                      #11
                      I agree with Otis on the Paul Burke idea. Do your research but I ended up with one of Paul's N21 grinds with no oversize eccentrics needed. Big improvement over the stock B-35 piece.
                      Never argue with stupid people, they will drag you down to their level and beat you with experience. -Mark Twain

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                      • VinniE30
                        R3VLimited
                        • May 2010
                        • 2113

                        #12
                        I've got the schrick 284/280 cam.
                        Is this 284 degree IE cam the same one? Or supposedly to the same spec?

                        I can't speak about the IE 284 cam but the schrick 284 is known to be not much more agressive than the stock M30B35 cam.
                        Heres some actual data and charts to that regard:

                        BMW probably underrates their cam specs or measures them in a slightly different way. So comparing a 284 cam to the stock B35 264 cam isin't what the numbers "284" and "264" suggest, since they are measured differently by different companies. You would actually have to measure them in the same way, like Devinder did.

                        It's easy to just say yes get the upgraded valve springs because they are stronger than the stock ones. But to be honest I would say you don't need them.
                        The B35 cam is the most agressive stock M30 cam and it has dual valve springs that were built for its cam and over-engineered just like most other engine parts. The slightly more agressive 284 cam would be fine with the stock springs. As you can see by the data the lift isin't much more than stock.

                        That said, I think the schrick cam definitely wakes the m30 up, it pulls noticeably harder, especially at higher rpms. But I modded the m30 in other ways at the same time so it's hard to say if it was mostly the cam or other things. Either way it's pretty fast.
                        Zinno '89 <24v swap in progress>

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                        • wannaBMthree
                          Mod Crazy
                          • Apr 2007
                          • 601

                          #13
                          Add Rocker Locks:

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                          • VinniE30
                            R3VLimited
                            • May 2010
                            • 2113

                            #14
                            Originally posted by wannaBMthree
                            Yes! Definitely get the rocker locks. I got these because of the broken rocker stories I read on the forums and the cause being the rockers having that lateral play from the springs. The stock rockers are actually very good, the reason for them breaking if you ever hear about them breaking is almost always because they move around the shaft at higher RPMs since the springs aren't strong enough to hold them perfectly still in place.
                            If I find any of the threads later i'll post them here.
                            Zinno '89 <24v swap in progress>

                            Comment

                            • SkiFree
                              R3VLimited
                              • Jun 2011
                              • 2766

                              #15
                              Originally posted by wannaBMthree

                              or here...


                              Looks like VAC stole some pictures!
                              ADAMS Autosport

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