'69 340 Questions

Small Block Mopar Engine

  1. yellow rose

    yellow rose Doctor of Thinkology.

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    How is it hard to make a 340 run? Doesn't the OP already have the 340? I have 3 blocks sitting in the shop. They aren't that hard to get. They aren't 50 bucks like 360... Oh wait I don't see many 50 dollar 360's out there. We must be talking 318 now.

    My point is the 360 isn't all that. Until the stroke gets up over 4 inches. Then you need the bigger main bearing for more over lap. Oh wait. The 340 main is big enough to handle a 4.125 stroke at least. Yet the 360 is still hampered by bore.

    The first thing you learn about air flow is don't crimp it. Want your heads to flow better? Use a bigger bore. That's why many people don't see an improvement using 2.02 valves.
     
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    • abodyjoe

      abodyjoe Well-Known Member

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      Who said it was hard to get a 340 to run.

      I said it’s not worth messing with a 340. Better off selling it to someone who will over pay for it because they still think it’s 1970 or they need it for their resto. Then with the extra money you made you can be that much further ahead with a 360. Not sure what’s so hard to comprehend about that. And I’ve found numerous 360 short blocks for $100 and under. Have 3 or 4 out there right now infact. Have had quite a few 340’s over the years and sold all them bitches for a nice profit every time.
       
    • yellow rose

      yellow rose Doctor of Thinkology.

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      Evidently you don't read what you post. You said it was hard to make a 340.

      Anyway, buhbye. The OP has a 340. Get over it. We all know you can't make a 340 run and you hate them. Sounds like penis envy to me.

      To the OP...laugh at fools like abodyjoe. There is a reason why a 340 gets a premium. No reason why not to use one.
       
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      • AJ/FormS

        AJ/FormS 68 B'cuda fb, Form S clone ... 367/A833/3.55s

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        YR; this is not even in the remotest way directed at you, nor to anyone in particular.

        AJ's ramblings;
        What I like about the 360, for a streeter, cuz that's all I know; is that you can either;
        A) put more cam into it before the bottom goes away,or
        B) with all other things being equal except the stroke difference; You'll end up with about a 10% stouter bottom-end, which will allow about 10% less stall, or 10% less rear gear. take your pick. And the 360 will yield a tad better hiway fuel economy....... Just try getting 30mpgUS out of a 340 with a 223 cam.
        I just bored my 360 out to 4.04, and called it a stroked 340. After that I didn't have to listen to all the car-show jokers tell me I shoulda built a 340: as if everybody and his uncle knows 340s were; " insert your own adjective here". and
        C) If you have a manual trans, those extra cubes more than make up for the lack of TM in the TC, so then you can run the same rear gear as the auto. Remember, with street gears, the engine is married to the rear axle and your engine is gonna be spending maybe 90% of it's life under 3500 rpm, which is about 30mph with 3.55s, in 2.66 low gear.............. There is going to be a seriously lotta time that your street engine is stuck at rpms under even 3000 in traffic, or whatever; that's when that extra 10% bottom end is gonna come in handy. Stuck because there is no fluid coupling. Sure you can ride the clutch, but you'll be buying clutches a whole lot more often. And besides, it's the same in second ..... and third...... and fourth.
        Say you have an A833 with 3.55s, here are the rpm to mph breakdowns in each gear,from 1500rpm to 3000rpm.
        This is 13 to 26 in first, and
        17 to 35 in second, and
        24 to 48 in third, and
        34 to 68 in fourth.
        So with an auto,and a 3500TC you will never find yourself in any of these zones.................. But with a stick,You are married to these zones whether you like it or not, and an extra 20/27 cubes is really gonna help make your day. You are gonna need some torque down there to make cruising relaxing. You can only downshift so many times before it gets old.
        D) but if you have an automatic with a 3500 TC well, point C) is kindof moot.
        But that is no longer apples to apples, cuz if this 340 sucked gas before, well, now it's really gonna. And IMO a streeter that sucks gas that bad is really no longer a streeter, but has become a weekend bomber.
        Do the math; $100 thru the week and another $100 on the weekend adds up to $4000 for the summer. You might as well have put a turbo'ed teener in there, and covered all the bases, and paid for the turbo kit out of the cost of the fuel saved in 2 years...... or so, and you could have had soooooo much more fun..

        Ok wait, what?
        AJ's ramblings.
         
        Last edited: May 25, 2018
      • Marcohotrod

        Marcohotrod Well-Known Member

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        a 340 is not crap joe. a bigger bore is better, but a 340 and a 360 can both be bored out the same, 4.060" or whatever. all 340s had floating pins, 360s not , etc. A 1969 340 had a steel crank and was internally balanced. all 360s had cast iron cranks and externally balanced-not ahead of the 340 game joey etc.
         
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        • Mattax

          Mattax Just the facts, ma'am FABO Gold Member

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          Com'on guys, It's going way off track. Lets stay on target :elmer:
          The question was not about selling it, whether it was a good buy, or how to do make power on a fixed budget like Lemons race or Grassroots challenge.

          Yes. Open it up. Check condition, and also a measure the distance in the hole or out of the pistons and CC the heads.
          For a long lasting street engine, a 340 cam is decent choice.
          Also see if the heads were ported. Someone putting a high lift cam in may have done some porting. If there isn't, even less point in going with cam lift resulting in something over .5"
          twocents.gif
           
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          • SGBARRACUDA

            SGBARRACUDA ROY FABO Gold Member

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            Rule of thumb? Buy on what you can see with your own two eyes. If you later tear the engine apart and it is more than you expected, consider yourself lucky. At this point, I would take that engine all the way down to bare block and inspect it. Standard bore after 50 years? Good? Possible, but I would have to verify it myself.
             
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            • abodyjoe

              abodyjoe Well-Known Member

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              Obviously you don’t comprehend what you read. I never said it was hard to make a 340 run good. Just said it’s not worth it. Sell it to a over paying clown and be money ahead with a 360.

              A 340 fetched a premium because guys think is still 1972. Lol
               
              Last edited: May 26, 2018
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              • abodyjoe

                abodyjoe Well-Known Member

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                That was a figure of speech. Just said to sell the bitch to someone that will over pay for it like so many resto guys will and be money ahead in the end with a 360.
                 
                Last edited: May 26, 2018
              • Richie

                Richie Well-Known Member

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                I'm no expert but I would check everything or get someone you trust who is an expert to do it.
                 
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                • Max Mccollum

                  Max Mccollum New Member

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                  I don’t think id go crazy about pulling motor down ,if the motor looks old greasy ect id pull intake and carb and see. As well as a full tune up ,how are the seals were they ever replaced ? Front main seal ? Oil pan gasket ? Valve cover gaskets ? If they all look well I’d do a tune up and throw the motor in the car. You’ll know right away if it had a cam or if he lied but a 340 is a great motor as is.
                   
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                  • 6pak

                    6pak New Member

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                    Every
                     
                  • 6pak

                    6pak New Member

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                    Everyone makes a good point.
                    You dint knwowhat u have until you teardown.
                    Better safe than sorry.
                    And the 360 angle is a good one.
                    That extra stroke makes a world of difference. Allot easier to find. And a magnum version would be great.
                    That cam (not broke in?). Would definatley run better in a 360.

                    The edelbrock carb will run well on it.

                    Take your time and do it right.
                    Good luck.
                     
                  • sireland67

                    sireland67 Well-Known Member

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                    Tear down and inspect what you have.
                    Post pictures, of bearings, etc its not hard, also keep things like rods, and caps together, and marked from the cylinder they come from.
                     
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                    • philgorg

                      philgorg Member

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                      GR5 comes in here asking about a 340 and some of you guys start into some kind of 360s are the best crap. that's your opinion. whatever. if you can't add some kind of pertinent advice or info, then go take a dump or something till the urge to spread your manure passes.

                      the teardown and inspection is definitely the way to go. the only thing i might add would be to attach the transmission and a starter to the engine and do a compression check before you tear down the block. the compression numbers might help you decide what your going to do next.
                       
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                      • moparownr

                        moparownr FABO Gold Member FABO Gold Member

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                        I would have checked for free rotation (plugs out), compression test, then run on floor. If you want this engine to stay together from now on....then take it apart and see whats in there, put it back together stock with an original grind cam. When done it will be sweet!
                         
                      • Wyrmrider

                        Wyrmrider Well-Known Member

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                        If you do tear the heads off check the deck height at all four corners to see if the block's square and so you can calculate compression
                         
                      • RustyRatRod

                        RustyRatRod Weenie idiot loser. FABO Gold Member

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                        Ok, so most 360s caint go .100 over but they can go .060. The 340 bore is safe to 4.100 (.060 over). So we're arguing about a .040 difference? Yeah, take that shit somewhere else.

                        I agree with Joe. Some guys see 340s as gold mines. Sell it. You'll be dollars ahead and can find a nice 5.9 Magnum and spiff that bad boy up with whatever stroke you want.

                        And anybody says Joe said a 340 is hard to make run is retarded. He said it's not WORTH spending money on a 340 when you can flip it for probably close to the same money you'd put into it, buy a 360 build it and have money left over.

                        I know the "already have it" argument all too well and usually agree with it, but here I don't think it applies.
                         
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                        • RustyRatRod

                          RustyRatRod Weenie idiot loser. FABO Gold Member

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                          No, nobody said that, either. We're talking about from a financial standpoint. The 360 wins out every time in dollars spent to build, when you can sell the 340 for a chunk.
                           
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                          • ir3333

                            ir3333 Well-Known Member

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                            360 ...dollars ahead,yes and no.
                            A body's are not collectible but a high end '70 or earlier A Body with a 340 will likely
                            be more valuable and desirable to many enthusiasts.
                             
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                            • Mattax

                              Mattax Just the facts, ma'am FABO Gold Member

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                            • abodyjoe

                              abodyjoe Well-Known Member

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                              Yes if it’s an original 340 Car. But it really doesn’t matter in my opinion on a /6 or 273/318 Car depending on the look and how it runs.
                               
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                              • RustyRatRod

                                RustyRatRod Weenie idiot loser. FABO Gold Member

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                                You think? Put yourself on the buying end. You'd be arguing all day long that it's not the numbers engine. We all would.
                                 
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                                • ir3333

                                  ir3333 Well-Known Member

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                                  I agree... but a some of the older guys that lived through the 'era would not want a '68 360 Dart or 'Cuda.
                                  I don't think numbers matching adds much to an A body's value unless it's an original big block.Certainly not like 6 figure B and E body cars.
                                   
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                                  • abodyjoe

                                    abodyjoe Well-Known Member

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                                    I’d bet if it were an original 340 Car the numbers matching motor would add quite a bit.
                                     
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