Bearing girdle or not???

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • Pat D
    S2Forum Maniac
    • Dec 2011
    • 748
    • Country: Australia

    #1

    Bearing girdle or not???

    Building a stroker with aim of about 600hp, maybe more. Would a girdle be recommended?

    I'm guessing that the face of the block where the oil pan meets up would have to be prefectly straight in order not to influence any twisting forces when the girdle is torqued up and itself possibly alter any clearances in bearings, or would the block be way too stiff for that to happen and I'm just paranoid? .

    I've never installed one and so not familar with the process of installing one.

    Any thoughts?
    ABY S2 stroker (work in progress)

    B5 1.8T quattro

    B4 2.3 (decommissioned)
  • driftin jo
    S2Forum Fiend
    • Sep 2007
    • 2222
    • Country: United Kingdom

    #2
    I wouldn't say it's necessary for 600hp but your motor will last longer between rebuilds for sure.
    If you going to do it you will have to machine the backs of the bearing
    caps and thus you will also require a skim of the face of the caps so an
    align bore can be done to bring it all true with it all fully assembled with the girdle and the caps all torqued up together.

    Comment

    • Thuppu
      S2Forum Freak
      • Sep 2010
      • 4115
      • Country: Finland

      #3
      According to Repo, no need for a girdle under 1000hp levels.

      Audi UrS4 Avant 2.5 20vt - twincharged - Project
      Audi 80q B4 Sedan 2.2 20vt - Daily user
      BMW 320d Touring e91 M-Sport - Daily user
      BMW 740iA e38 - Project

      Comment

      • MrVain
        S2Forum Enthusiast
        • Oct 2008
        • 189
        • Country: Sweden

        #4
        I agree with Repo

        Comment

        • Jamo
          Retired OG Mod
          • Mar 2004
          • 21750
          • Country: United Kingdom

          #5
          Overkill on a stroker

          Comment

          • Pat D
            S2Forum Maniac
            • Dec 2011
            • 748
            • Country: Australia

            #6
            Might go without then as I won't be racing the car when it's done. Thanks for the input everyone
            ABY S2 stroker (work in progress)

            B5 1.8T quattro

            B4 2.3 (decommissioned)

            Comment

            • Thuppu
              S2Forum Freak
              • Sep 2010
              • 4115
              • Country: Finland

              #7
              Well, if you have the money and place for linehoning, machining the bearing caps and making the shimms, go for it. It's a nice high end engine detail, and surely have some benefits on high power levels, but it's mostly a question about the price you wan't to spend... your engine is great also without it, especially if you don't target to monster big power levels.

              Audi UrS4 Avant 2.5 20vt - twincharged - Project
              Audi 80q B4 Sedan 2.2 20vt - Daily user
              BMW 320d Touring e91 M-Sport - Daily user
              BMW 740iA e38 - Project

              Comment

              • JariP
                S2Forum Enthusiast
                • Jul 2003
                • 192
                • Country: Finland

                #8
                I'd say it's more about high rpm levels than power. If you are going to rev it continuously up to 9000-10000 rpm or more, then a girdle might be useful, otherwise forget it.

                Comment

                • urs4guy
                  S2Forum Enthusiast
                  • Dec 2007
                  • 192
                  • Country: United States

                  #9
                  After spinning our local dyno to the tune of 755hp, we took a very close look at things and discovered some interesting damage. We had actually twisted the block and destroyed the passenger side motorsport spec motor mount. As a result we've torn everything down and launched a multi-pronged effort to cure these issues.

                  First is a girdle and a heftier set of ARP studs. Another area that demanded attention was the minimal damage to the head from the head moving about the head studs that elongated their bores in the head. The remedy here is a heftier ARP stud with a bored out stud bore that will be lined with a steel liner. The girdle itself is a custom unit machined locally.

                  Next is the triple set of motor mounts that attach at 3 points going forward from mid of the transmission to the rear of the block, via a mid-plate, and at the front of the motor. These will lock that motor in place. In order to beef up the chassis to hold things together we had to go with a custom sub-frame and main frame reinforcement or it just wouldn't work. The results will speak for themselves but for now, I just have to wait to get everything back from vendors doing bits of work. The only really new mod for the engine is the custom billet crank that does take a long time. Also out is the CRB transmission which is getting a preventative refresh with Quaife limited slip for the front axles which will match up with the same for the rear diff.

                  Anyway sorry for the long answer but yes, I think a girdle is merited.

                  Hap, wit dakine girdle not from Evahboost, Maguire

                  Comment

                  • urs4guy
                    S2Forum Enthusiast
                    • Dec 2007
                    • 192
                    • Country: United States

                    #10
                    Originally posted by JariP
                    I'd say it's more about high rpm levels than power. If you are going to rev it continuously up to 9000-10000 rpm or more, then a girdle might be useful, otherwise forget it.
                    As you can read above, the damage was from the power of the motor. I have never taken it above 7600 rpm. Our theoretical redline is 8200 rpm.

                    Hap, wiit dakine redlines not from Evahboost, Maguire

                    Comment

                    • terrybullwon
                      S2Forum Zealot
                      • Mar 2006
                      • 8782
                      • Country: England

                      #11
                      If your going to do it, this is the best way.

                      Credit to Jp

                      Chef

                      Comment

                      • Thuppu
                        S2Forum Freak
                        • Sep 2010
                        • 4115
                        • Country: Finland

                        #12
                        This is even more extreme, full cromo bearing caps.


                        Audi UrS4 Avant 2.5 20vt - twincharged - Project
                        Audi 80q B4 Sedan 2.2 20vt - Daily user
                        BMW 320d Touring e91 M-Sport - Daily user
                        BMW 740iA e38 - Project

                        Comment

                        • Jamo
                          Retired OG Mod
                          • Mar 2004
                          • 21750
                          • Country: United Kingdom

                          #13
                          Originally posted by urs4guy
                          After spinning our local dyno to the tune of 755hp, we took a very close look at things and discovered some interesting damage. We had actually twisted the block and destroyed the passenger side motorsport spec motor mount. As a result we've torn everything down and launched a multi-pronged effort to cure these issues.

                          First is a girdle and a heftier set of ARP studs. Another area that demanded attention was the minimal damage to the head from the head moving about the head studs that elongated their bores in the head. The remedy here is a heftier ARP stud with a bored out stud bore that will be lined with a steel liner. The girdle itself is a custom unit machined locally.

                          Next is the triple set of motor mounts that attach at 3 points going forward from mid of the transmission to the rear of the block, via a mid-plate, and at the front of the motor. These will lock that motor in place. In order to beef up the chassis to hold things together we had to go with a custom sub-frame and main frame reinforcement or it just wouldn't work. The results will speak for themselves but for now, I just have to wait to get everything back from vendors doing bits of work. The only really new mod for the engine is the custom billet crank that does take a long time. Also out is the CRB transmission which is getting a preventative refresh with Quaife limited slip for the front axles which will match up with the same for the rear diff.

                          Anyway sorry for the long answer but yes, I think a girdle is merited.

                          Hap, wit dakine girdle not from Evahboost, Maguire
                          interesting hap but you were using the 220mm block, the 236mm diesel block is beefier and takes more punishment to the point if your below 700 bhp you shouldn't really need it

                          Comment

                          • Mcstiff
                            S2Forum Maniac
                            • Oct 2004
                            • 504
                            • Country: United States

                            #14
                            Originally posted by Jamo
                            interesting hap but you were using the 220mm block, the 236mm diesel block is beefier and takes more punishment to the point if your below 700 bhp you shouldn't really need it
                            Hank Iroz in UT has commented on how much beefier the "tall deck" block is. Wish we had more in the US (we only got them in the 10v vans).
                            1995 1PissedOff90sigpic1991 USDM CQ 7aT

                            Comment

                            • andy10v
                              S2Forum Zealot
                              • Mar 2009
                              • 5996
                              • Country: Scotland

                              #15
                              Originally posted by Mcstiff
                              Hank Iroz in UT has commented on how much beefier the "tall deck" block is. Wish we had more in the US (we only got them in the 10v vans).
                              Did he not manage to twist an earlier 10v block without the reinforcing webbing on the side?
                              Current-2004 Impreza PPP wagon

                              Sold-92 3B coupe-RS2+, 996s, konis, rear torsen, forged rods........
                              Sold ABY-stock

                              Comment

                              Working...