1. Green72

    Green72 Active Member

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    IMG_0107.JPG IMG_0119.JPG IMG_0120.JPG IMG_0131.JPG I've always wanted to build my own engine. I am planning a 440 based stroker. I have located a running 440 out of a motor home. The casting date is 1976. I am planning on updating this thread as I make progress in the hopes that you guys will jump in if you see a rookie mistake!! I did start to disassemble the motor, so far all looks really good. The supposedly virgin block looks to be .030 over. How much can it be bored
     
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    • jamie

      jamie Well-Known Member

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      .031:)

      Have to have it sonic checked to know for sure.
       
    • bearman

      bearman FBBO Gold Member FBBO Gold Member

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      I wonder why .30 over. Most motor homes engines have low mileage. But yet you say it's already overbored. When I was looking for my 440 I looked at a half a dozen engines and again most of them from motor homes 60,000 was alot. I like the motor home blocks because of the oil and water passes. But it has to be Sonic tested and fined someone to do machine work that you trust
       
    • Runner 68

      Runner 68 Tarnished Bronze Member FBBO Gold Member

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      :drinks:.......:popcorn:
       
    • bearman

      bearman FBBO Gold Member FBBO Gold Member

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      I have a 76 block that I used from a motor home it had 42,000 on it I could have keep standard bore but went .30 over going to build a 505 out of it.
       
    • 451Mopar

      451Mopar Well-Known Member

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      0.055" over (4.375") is fairly common if you have to go over 0.030". The obvious question is why 0.055" and not 0.060", and the answer is piston ring choice. There is a wider selection of 4.375" diameter rings (so usually less expensive too) than 4.380" rings.
      the 4.25" stroker kits are fairly easy to put together, but as I have been telling my friend Dan when we were building his 505" stroker, you have to check everything because all these new parts have never been together before. Quite a bit different than re-using stock parts that were already together in the engine.
      Not sure how hot (or expensive) of an engine you are planning, but changing to a 1/2" NPT oil pickup tube can be one of the bigger issues. We messed around quite a bit to get a generic 1/2" pickup tube to fit the off-brand oil pan. Reaming the main oil feeds is pretty easy modification, and most likely only one you may need (if any?)
       
    • ChargerST

      ChargerST Well-Known Member

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      Does a 0.005 difference in diameter really make a difference for piston rings?
       
    • MoparLeo

      MoparLeo NRA PATRON LEVEL LIFE MEMBER FBBO Gold Member

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      First off, you need to learn to walk before you run. Before you spend a dollar on the engine, you need to do your research. Any Good engine builder will tell you to decide exactly what you are looking for the engine to do for you, ( high rpm, low rpm, high horse, torque, car weight, differential gearing, longevity etc...) and once you decide the combination, stick with it. The biggest mistake you can make is to start changing your mind in the middle of the build what you now think you want.. Building an engine is like preparing a meal. Use the wrong ingredients or cook at the wrong temp for the wrong period of time and you end up with something that you won't like to eat. Learn to use a recipe book first, than create your own later.
       
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      • wyrmrider

        wyrmrider Well-Known Member

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        nice and clean
        can you find out who built it
        can you X-Y measure the bores and see if was bored and honed with a torque plate
        can you just do a minimum hone for your stroker kit
        OR
        hone with a torque plate to .040 over (or .050- .060)
        check each bore to see if it still has hone marks- any worn away of home marks spots? measure them
        see post above about figureing out where you want to end up
        also measure the deck height of all four corner pistons to see if they are the same before removing pistons- report back
        this may tell you if the block as been decked already, or will need decking and to show where you are at
        is timing chain new?
        cam new or stock
        keep the lifters in order so they can go back on the same lobe- while inspecting
        they cam you need may already be there but if you mess up the lifter order you will need to resurface or buy new lifters
         
      • Green72

        Green72 Active Member

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        Thanks everyone, already good advice.
        No way to find out who built it.
        I can measure X-Y on bores. Will that indicate that it was done with torque plate?
        I will measure all four corners and report back
        Could be awhile with the holiday
         
        Last edited: May 22, 2019
      • 451Mopar

        451Mopar Well-Known Member

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        So, what is the plan for this? The GTX or Scamp?
         
      • Green72

        Green72 Active Member

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        It will go in the GTX.
         
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        • Green72

          Green72 Active Member

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          Well it's been awhile but I finally got back to checking out the block for this build. I did go to machine school and work at a mold and die shop for a couple years. That was a long time ago. It took me awhile to acquire and relearn the measuring tools! I used a dial bore gauge set up with an outside mic to take bore measurements. I took X and Y on the top and middle of each bore as shown in the pic. I have not removed the pistons yet. I wanted to see what you guys thought so far? I also measured the deck height on the 4 corners as shown. Obviously the block is .030 over, the is no ridge at the top of the bore and cross hatching is clearly visible on all bores. That's all good right? Let me know what you think and what the next step should be.

          IMG_0132.JPG
           
        • Green72

          Green72 Active Member

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          IMG_0135.JPG Better pic
           
        • wyrmrider

          wyrmrider Well-Known Member

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          Well you have one end of one bank that appears low
          It could be the block or it could be tolerance stack of the pistons and rods
          you can rough check by using the same piston and rod to check all four corners
          but that will not tell you if the decks are tilted- just end for end
          if still off your machinist will have to check if you want to "blueprint" the block to some reasonable spec
          so how close do you want to be?
          what is your quench goal and how close do you want to be?
          looks like a low mileage rebuilt so you could do a minimum hone with a torqueplate
          if not done before with a torqueplate it will show up but may not make much difference in your stroker build ie it may clean up with .001
          if not doing a stroker you could hone yourself and slap in some higher compression pistons (depending on head selection) and compression/ build goals
          if the hone with torqueplate shows egg shape or hourglass or funnel shapes then you will have to go .040 if bad enough
          .040 works fine
          so if the quick check fails you might want to stick it in the hone and give it a few strokes before you buy stroker kit
          or just buy .040 stroker kit
          use common sense since you say no wear and can still see the crosshatch
          you might be able to have an agreement with your stroker kit vendor to swap .030 pistons for .040 if the hone finds hidden wear
           
        • Green72

          Green72 Active Member

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          Thanks for the response. I will check all four corners with the same piston and rod. I am going to use a 440 Souce 500 inch kit. There chart shows .018 below deck (quench?). I am planning on having the machinist evaluate the bore and decide on piston size.
          I was surprised by how far below deck these pistons are, is this normal? Is it due to shorter pistons or shorter stroke? How much can come off the deck before issues arise with intake alignment.
           
        • wyrmrider

          wyrmrider Well-Known Member

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          we do not know where that .018 dimension comes from do we- find out at what deck height-- crank Cl to deck
          (mopar rod length or longer chevy rods)
          then to double check ask them "at what deck height is that .028 figured- like you might actually cut to that height (which will give you too much quench quench
          now if the pistons actually were .018 down and you used a .028 gasket and closed chamber heads you would be at .046 quench- which is too much
          now lets say the block is actually .006 down on one end and we take .010 off to square it up - well we still do not know about how the .018 was calculated but we would be at .036 quench which is sorta ok
          if you use thick gaskets you have to take more off
          your intake alignment will be ok at this range of mill as your gaskets at even .028 are thicker than stock
          did you say what heads? and how many cc's are the actually?
          ask this board for others experiences with the proposed head (s) real cc's
          then get your proposed compression ration and figure your piston cc's do not think of ordering pistons till you do this
          Make sure your shop has the tooling and or the patience to actually cut the block square(45 degrees) to the crank/ cam centerline
          if you have to line bore do it first
           
        • Green72

          Green72 Active Member

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          Ok I understand the goal here. What I'm confused about is how to calculate the deck height. What is the standard deck height and how would I measure. Since my block is an unknown, and I don't know the dimensions of the rods and pistons that are in it. Once I'm clear on this I will call to find out the deck height they are using to get the .018.
          They are showing a 6.760 rod ,4.150 stroke
          Compression ratio is figured with .018 below deck and a .039 head gasket .057 squish correct? I know you said that's to much.
          I am going to use Trick flow 240's they claim 78cc's
          Once I get my head wrap around some more of this I will figure out the correct pistons. I won't order anything until I fully understand
           
        • wyrmrider

          wyrmrider Well-Known Member

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          10.72 1.725 but is that actual or Blueprint-NHRA minimum
          you can measure with crank out with a large caliper main bearing saddle to deck and then half the housing bore to get to the center of the crank
          you can get end to end, cannot check for low side that way but it will give you an idea-- you may have a low corner so you need better from a quality machine shop
          but at least you will understand what's happening and can ask the correct questions (there are no stupid questions BTW)
          .057 is .020 too much
          ask this forum for those who have actually cc'd the 240's and are they ok OOTB or do they take a clean up, guides checked etc (edelbrocks do)
          then figure the piston net cc's requied
          you can open up the chambers maybe and gain 5cc if you need to- so ask and do searches here on 240 threads
           
        • Green72

          Green72 Active Member

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          Your patience is greatly appreciated. I will do more research report back.
           
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