1. nodemon

    nodemon Well-Known Member

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    0919211308c.jpg 0919211308c.jpg 0919211308e.jpg 0919211313.jpg 0919211312i.jpg 73 318 engine in my 72 Demon.
    I've asked plenty of dumb, newbie questions here and those that have answered have helped me out as I'm learning and bringing my Demon back to life.
    I bought this car not running, but told, "it ran" . For some reason the engine was pulled to replace the clutch and when engine was set back in, all accessories were left off.. It did turn over by hand.. Anyway, I purchased a set of fresh rebuilt 302 casting heads..an Edelbrock LD4B intake and an Edelbrock 650cfm. carb. Pulled the heads and intake off the engine to swap these out and discovered some dense sludge, several bent push rods with a couple having some of the metal scraped off and evidence of a couple of valve kissed pistons.. nothing too bad or deep, but they definitely touched.
    My question is, and realize without seeing yourself and other factors, it'll be hard to answer, but some of you have seen enough of this to possibly help... Do the bent push rods indicate a major issue..? Do pistons automatically need to be replaced with minor valve indents.. ? At this point, should I just pull the short block out and rebuilt it..?
    If I do rebuild it, do the cylinders have to be bored or just honed..?
    Thanks in advance for those that I know will help.. You guys are awesome..! Understand that I'll probably have plenty more questions after some answers start coming in. lol
     
    Last edited: Sep 23, 2021
  2. Dana67Dart

    Dana67Dart The parts you don't add don't cause you no trouble FABO Gold Member

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    Probably the pistons are ok,

    Rhe sludge is indicitave of a poorly maintained engine, so bearings would be suspect.

    If time and finances are available might as well rebuild before you put the new parts on it.

    Hone vs bore will only be known after engine is inspected with bore gauge.
     
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    • nodemon

      nodemon Well-Known Member

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      Thanks for your response..!
       
    • Murray

      Murray FABO Gold Member FABO Gold Member

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      I have never seen pistons with such small valve reliefs and am suspicious of cam "lift" or cam chain stretch. Bent push rods confirm this. I am not trusting anything about this motor and would only be happy tearing this motor down and starting over again. Sorry, just my opinion.
       
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      • 1966Post

        1966Post Well-Known Member

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        I concur with Murray. Take it apart once and do it right. In the end you’ll be happier
        It’s usually also cheaper to do it right once than wrong and then right…..
         
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        • nodemon

          nodemon Well-Known Member

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          No, I think you're right.. Smart thing to do is rebuild.. Those valve reliefs are not reliefs at all.. Valve strike..
           
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          • cudamark

            cudamark FABO Gold Member FABO Gold Member

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            The cam doesn't look all that great either. I'd pull it down and start over.
             
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            • nodemon

              nodemon Well-Known Member

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              What on the cam are you seeing..? I wasn't sure what to look for.
               
            • cudamark

              cudamark FABO Gold Member FABO Gold Member

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              The wear, deposits, a bit of pitting.....
               
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              • toolmanmike

                toolmanmike Moderator Staff Member FABO Gold Member

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                Those aren't valve reliefs the valves ran into the pistons. Wrong cam, cam timing, timing chain etc. You need to be careful with flat tops.
                 
                Last edited: Sep 26, 2021
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                • TT5.9mag

                  TT5.9mag Two atmospheres are better than one

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                  For someone just learning (key piece of information) here is my advice. Buy another engine and keep that one as a tool. You could probably pick up a magnum 318 for cheap, slap your accessories on it, with a new intake, and have the car running in a weekend. Then use that engine as a classroom, tear it down and teach yourself how to build an engine correctly when youre in no hurry to get it back in your car. Just a thought.
                   
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                  • nodemon

                    nodemon Well-Known Member

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                    Yep, I'm actively looking for one now.. !
                     
                  • toolmanmike

                    toolmanmike Moderator Staff Member FABO Gold Member

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                    Exactly. I don't see much reusable here if you want to do it right.
                     
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                    • 65TerrorCuda

                      65TerrorCuda Well-Known Member

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                      Missed a gear, overrevved, valves hit pistons and bent pushrods. Bend em back straight, reassemble and drive if funds are tight. My uncle did this exact thing in the 60's in his Barracuda.

                      Not saying you should though
                       
                    • RustyRatRod

                      RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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                      Someone probably over revved it playing around and valves floated and hit pistons. I would recommend pulling it and going through the short block, if for no other reason than to get everything machine shop clean. That way, you've not wasted good money on rebuilt heads going on a crappy short block.

                      Plus, you can decide if you want to upgrade the camshaft, to go with the stellar induction system you've chosen. You will want to have the matching valve springs installed on your heads, as the springs need to match the camshaft. The Comp 901-16 spring will handle anything you will ever want to put in that's under about .500 lift and they're very affordable. I would even add in some budget headers and that would make for a really nice little engine.

                      I would recommend something like the Lunati High Efficiency series. Something like this one.

                      https://www.lunatipower.com/high-efficiency-hydraulic-flat-tappet-cam-chrysler-273-360-268-268.html
                       
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