Big Block Chevy Intake Manifold tech

Discussion in 'Engine Topic' started by Chevyforever, Mar 13, 2019.

  1. Chevyforever

    Chevyforever Veteran Member

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    A common problem is over torquing valve cover fasteners which can distort the flat edge of valve covers or cut the gasket material and oil finds its way out. I personally always glued my cork gaskets to the covers and tried not to over torque. Over the years (30 +) I have had lightweight alum. Moroso covers, heavy cast alum. covers and chrome plated steel covers. I guess my personal favourites where the old light weight gold anodized Moroso. From a durability standpoint the heavier cast aluminum covers are pretty tough,
     

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  2. 1980RS

    1980RS Veteran Member

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    Sometimes I have found that if you don't seal the intake bolts can leak on the intake or it's possible that you have a crack in the intake some place.
    Any pictures of the puddle?
     
  3. Francesco

    Francesco Veteran Member

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    I'll try to take pictures to show you what it is. Thanks!
     
  4. Francesco

    Francesco Veteran Member

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    That's true because on one side I can see the gasket is sticking out a bit. That's a good point.
     
  5. Francesco

    Francesco Veteran Member

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    Hey! I wasn't able to take pictures but I know that small leak is coming from that bolt. There are no cracks. I checked the oil dipstick and it indicates that the oil level is a little over the full line. I wonder if that's what could of caused the oil to push up and seep out due to pressure. Now, what are my options with this leak? I don't want to take off the intake to put it back on for just one bolt or do I have to? Can I just put some RTV around that nut to stop it from leaking and take out oil from the engine to give it more room in the chamber?
     
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  6. Rich Schmidt

    Rich Schmidt Veteran Member

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    Francesco,it might not be oil. If the carb is dripping gas it could be fuel. I have a friend who went nuts changing things on his roots blown engine looking for an oil leak only to find out that fuel was weeping thru the gasket under the blower and once it got on the intake it would attract dirt and start to look like oil sludge. The same thing would happen if fuel was weeping out around a worn throttle shaft of thru the gasket between the intake and carb. Even if the gasket is good gas will travel thru it.
     
  7. Francesco

    Francesco Veteran Member

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    Ahh1!!!! hmm...If my car runs rich, and I tend to flood it sometimes, do you think that it would accumulate on the intake after a while? But doesn't gas evaporate? how does it create a deposit? Yes, it does look like oil sludge. I didn't know that gas can leak and create an oil like deposit. thanks for the info Rich!
     
  8. jeff swisher

    jeff swisher Veteran Member

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    Gas will make a brown stain looking area and will evaporate.
    I also have one intake bolt wicking oil up the threads even used Ultra black on the threads of the bolt and let it set overnight.
    Sometimes that happens.
    Remove bolt and clean it and threaded hole and seal it with Ultra grey which is a bit stiffer and may fix it.
     
  9. 1980RS

    1980RS Veteran Member

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    You can use RTV but pipe sealant works much better. Glad you found your leak, I just stripped the paint off my strip dominator and found 2 cracks, funny what you miss when the intake or heads are painted black. Looks like it's repair time again.
     
  10. Francesco

    Francesco Veteran Member

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    What causes a cracked intake? Does it mean you need to change the intake all togheter?
     

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