Oil leak at valve covers

Discussion in 'Small Block Mopar Engine' started by Dakota Smith, Sep 9, 2018.

  1. Dakota Smith

    Dakota Smith 1976 340 Feather Duster

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    I installed a new set of cork valve cover gaskets recently and oil residue is visible all around both valve covers, but it isn’t dripping oil out. Are cork gaskets just crap? Should I have put some type of sealant under the gaskets?
     
  2. mderoy340

    mderoy340 Well-Known Member

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    A little contact cement on the valve cover side, grease on the head side. Do not over tighten works for me. If they are OEM most head surfaces are rough and uneven.
     
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    • famous bob

      famous bob mopar misfit

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      I have aftermarket alum. heads, all smooth on the rail surfaces, I`ve tried about every gasket I`ve seen, and still have a little oily residue under the valvecover rail. I`ve cleaned the cast valve covers too, even have hughs non - burnable gaskets installed the way they recommend-----------
      doesn`t drip tho.
      right now anyway !
      Wish the 440 blocks had the corner drain holes like the elephant !
       
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      • BeepBeepRR

        BeepBeepRR Well-Known Member

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        Last edited: Sep 9, 2018
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        • abodyjoe

          abodyjoe Well-Known Member

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          • krazykuda

            krazykuda FABO Gold Member FABO Gold Member

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            I like the fel pro neoprene rubber valve cover gaskets... Just tell them that you have a 64 - 67 273 for the proper listing.... Those years had adjustable rockers so the rubber neoprene ones are reusable.....
             
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            • ir3333

              ir3333 Well-Known Member

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              Cork are like old cedar boats or wine bottles.Once saturated they should expand and seal.
              Like wine bottles stored on their side to keep the cork wet and expanded, if you rarely use your car they will dry out and be ineffective.
              always seal to the valve cover,the oil will not run up and overt the lip on the head...over tightening is usually the problem.
              i have never had cork leak if properly installed.
               
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              • toolmanmike

                toolmanmike FABO Staff Staff Member FABO Gold Member

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                And if you are using the original type steel covers make sure the metal is flat around the bolt holes. A vice jaw or a 2x4 and a few light taps with a hammer helps straighten them out.
                 
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                • 4spdragtop

                  4spdragtop FABO Gold Member FABO Gold Member

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                  Very important what TMM said. The valve cover rails and bolt holes need to be straight so when bolted down it pulls vc down snug.
                   
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                  • Murray

                    Murray FABO Gold Member FABO Gold Member

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                    The bolts often leak too. A little RTV on each bolt can fix it.
                     
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                    • TrailBeast

                      TrailBeast Slightly Twisted Member

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                      I used to use the black rubber gaskets with a thin coat of RTV on both sides, and making sure I had RTV between the bolt shafts and oil side of the rails.
                      Never a leak.
                      Cork always seems to seep eventually, and the rubber with RTV never will.

                      Now that I have aftermarket heads with machined flat rails I use the metal core rubber gaskets, but still use the RTV exactly the same way.
                       
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                      • famous bob

                        famous bob mopar misfit

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                        I don`t want to glue both sides, running a solid roller, need to remove once in a while to set/check the valves---- I do have a pair of $38 gaskets on it now. I have built heat guards to help keep the heat off of the valve covers and gaskets, #1-2 tubes are very close to the covers w/ raised port heads. It burned the cork, rubber steel reinforced, and every other kind I tried , ones up after a while , hoping these carbon gaskets will hang in there.
                         
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                        • H22A4

                          H22A4 Well-Known Member

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                          • TrailBeast

                            TrailBeast Slightly Twisted Member

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                            Sounds reasonable to me.:D
                            I am running LA style fabricated aluminum covers with the Magnum rubber over steel gaskets on aftermarket heads with a hydraulic roller, so I don't have those kinds of problems any longer.
                            It's a daily everywhere car so it needs to be low maintenance.

                            One messed up thing I found when I had the 318 and used the fabbed covers was the valve cover rails are not flat front to back.
                            They are higher in the center by about 3/16 inch, so I had to get creative about making gaskets for them.:D
                             
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                            • famous bob

                              famous bob mopar misfit

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                              Checked all the surfaces=flat , the problem is the header heat being so close to the gasket----------Think I`m repeating myself , oh well , I`m getting Older !!
                               
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                              • TrailBeast

                                TrailBeast Slightly Twisted Member

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                                I got ya, and was just relaying what happened with my junk.:D
                                 
                              • charles mill

                                charles mill Wildman68 FABO Gold Member

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                                no they r mother nature . seal them be easy point no oil I think god said was enough.