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  • Crankshaft repair. Truly amazing.

    I find this repair incredible. His use of calipers must come with years of practice. I don't get how he can keep the crank orientated and the bearing journals at the same gap size.
    https://www.youtube.com/watch?v=wUB7dUjFGIM

  • #2
    That was incredible. The accuracy of his welding I had to see to believe. Can't help but wonder just how accurate he got that crank.
    Last edited by Sparky_NY; 12-26-2021, 07:35 AM. Reason: Went back and read the comments on that video, very interesting.

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    • #3
      Whatever caused it to break in the first place, poor casting, broken rod etc. that corner weld certainly isn't going to hold up. I give it about one week of use.

      Comment


      • #4
        Originally posted by gbritnell View Post
        Whatever caused it to break in the first place, poor casting, broken rod etc. that corner weld certainly isn't going to hold up. I give it about one week of use.
        X2, I won't even watch the whole thing just the first two minutes is enough to make a judgment call...

        His only saving grace is the fact that it's the front snout and is only having to deal with one power stroke and not the accumulation of several with the flywheel side attached, but one has to keep in mind it broke for a reason in the first place - there's still a front harmonic balancer with tensioned belts and a pulley system hanging off the end, you do not "repair" cranks this way - you just turn them in for scrap....

        I don't care if they run the engine 10 degree's retarded and de-tune the throttle cable to half travel --- it's days are numbered from the get-go...
        Last edited by A.K. Boomer; 12-26-2021, 10:26 AM.

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        • #5
          A true craftsman at work.

          It looked like it was made from two crankshafts to get the overlapping length, or did the short end have a bit added on?
          From the number of crankshafts being worked on, they must have a long enough life to keep in buisiness. If the repair did not last, nobody would bother doing it.
          Last edited by old mart; 12-26-2021, 10:50 AM.

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          • #6
            Originally posted by gbritnell View Post
            Whatever caused it to break in the first place, poor casting, broken rod etc. that corner weld certainly isn't going to hold up. I give it about one week of use.
            If that were the case he wouldn't be there very long.
            From the looks of it he's been there long enough to have rebuilt the crank for the Arc's main propulsion unit.
            Len

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            • #7
              It all sounds good on paper till it inevitably breaks again this time (and maybe last?) taking out the entire engine block in the process...

              Some thing's you just have to do right to begin with and in fact especially if your dealing with po-pholk as they cannot afford to do it any other way...

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              • #8
                I agree, probably won't last long. 6013 rod, no preheat, obviously not a cast iron crankshaft, which is the only way he can get away with this. Still, pretty amazing that he gets these done in this manner and time. Probably cheaper than new CS, but certainly not up to original specs for strength, balance, etc.

                I have a friend in Bonners Ferry, ID, who has had a mower repair shop for many years. He routinely heats up bent mower crankshafts and bends the straight on his HF 13x40 lathe, dialing them in true. He's not had any fail, that he knows of, anyway.

                Dan
                Salem, Oregon

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                • #9
                  Originally posted by A.K. Boomer View Post

                  X2, I won't even watch the whole thing just the first two minutes is enough to make a judgment call...

                  ..............
                  That's unfortunate AK, you could have learned something.
                  A closed mind is much like a closed road, it goes nowhere.

                  Actually I watched this video a number of days ago and referenced to it in an other thread here a day or two ago.
                  This man is indeed a master at what he does and judging by the number of cranks in the shop his services are much sought after. I don't think he makes many mistakes or he would not have the workload he has. He fixes the mistakes of others.
                  The video goes into great detail on his pre-weld prep, rough and final indexing and straightening.Some very basic and sound practices demonstrated here that show us that you don't necessarily need a million dollar shop to fix a crank for a tractor. Some very good home shop capable techniques here.

                  These folks cannot afford new custom CNC 4340 crankshafts that are perfect in every way, they don't live in that perfect world. They do however need their crankshafts rebuilt for their cars, trucks, and tractors, they can't afford not to have them fixed rather than replaced.
                  These cranks aren't going into F1 cars or AA/FD quarter milers, they don't have to be perfect, just functional, and I'll bet he makes them live long enough to be a very viable choice.

                  Trust me you owe it to yourself to watch it with an open mind, you will learn something.
                  Home, down in the valley behind the Red Angus
                  Bad Decisions Make Good Stories​

                  Location: British Columbia

                  Comment


                  • #10
                    Originally posted by Willy View Post

                    That's unfortunate AK, you could have learned something.
                    A closed mind is much like a closed road, it goes nowhere.

                    Actually I watched this video a number of days ago and referenced to it in an other thread here a day or two ago.
                    This man is indeed a master at what he does and judging by the number of cranks in the shop his services are much sought after. I don't think he makes many mistakes or he would not have the workload he has. He fixes the mistakes of others.
                    The video goes into great detail on his pre-weld prep, rough and final indexing and straightening.Some very basic and sound practices demonstrated here that show us that you don't necessarily need a million dollar shop to fix a crank for a tractor. Some very good home shop capable techniques here.

                    These folks cannot afford new custom CNC 4340 crankshafts that are perfect in every way, they don't live in that perfect world. They do however need their crankshafts rebuilt for their cars, trucks, and tractors, they can't afford not to have them fixed rather than replaced.
                    These cranks aren't going into F1 cars or AA/FD quarter milers, they don't have to be perfect, just functional, and I'll bet he makes them live long enough to be a very viable choice.

                    Trust me you owe it to yourself to watch it with an open mind, you will learn something.
                    Willy - i respect your opinion - I am always amazed that the resourcefulness and also the SKILL of these types of hard working people,

                    In fact id put this guy in the same category of the people building axles out of chain links! amazing to say the least, but high quality axles? not a chance --- I did watch that entire vid - again amazing - but totally crude axles and who knows about the steel, the guide hole's were drilled on a drill press with a worn out guide hub, the bit's were wobbling all around - the holes are of course totally out of wack but "close enough for lugs" well in away but some will be crooked due to being off pattern and then having to get sucked up against the properly machined and spaces wheel so they will be under great stress in area's and fail prematurely ---

                    that's just the tip of the iceberg,,, and with the cranks? name of the game is they all have to flex as a unit, they will most likely fail right where the weld meets the crank material, the harmonics/frequencies/vibrations just in running will catch up to it let alone power strokes and like I said good chance of taking out an engine block or locking whatever vehicles drivetrain up around one of those cliff hanger roads it's probably going to be on... count me out - again totally amazing - but I cannot applaud - sorry....

                    Comment


                    • #11
                      These cranks he fixes work. Its obvious. You dont get that good at something if you dont have repeat business. This guy could work on brain muscle memory and work blindfolded. If you look at his crankshaft hydraulic straightener jig who would bother building that if it had no success. His welding is unbelievable.
                      I love his cylindrical grinder /polisher. Its real clever.
                      The only criticism I have is Damn he smokes wayyyy to much.
                      Personally if you told me you can weld a snapped crank I would laugh at you.

                      Comment


                      • #12
                        What many are forgetting is this --- limited resources and tons of time,,,

                        so could be even if one in ten cranks pans out for a year or two they call it "worth it" might also mention initial engine designs that are flawed meaning a surplus of blocks with cranks that fail prematurely... the attitude then is "hell yeah lets toss a hail mary at it and see what happens"

                        Just because people are "doing it" does not mean its "right"....

                        Comment


                        • #13
                          Originally posted by gbritnell View Post
                          Whatever caused it to break in the first place, poor casting, broken rod etc. that corner weld certainly isn't going to hold up. I give it about one week of use.
                          Didja LOOK at it?

                          To me, regardless of the advisability of doing the repair, and complaints about rod type, etc....it does not look that bad.

                          NOT a "corner weld", the v-groove was deep enough to get good strength. quite a bit of weld metal in there, torsional strength should be fine, particularly when it is not at the most stressed portion of the C/S. Most of the strength is on the OD portions of a shaft and depth beyond what was obtained is not likely to increase strength particularly.

                          If the full cross section stands the torque back at the flange, the cross section of material the repair has will stand one cylinder's worth out of 6.

                          Not a casting either..... look at the chips, and the fact that it welded fine.... it's steel.

                          A good "save" by the repair guy. Something else will break before that weld will, in the use it will get. That gets done every day, and works. As others said, if it did not, that guy would have to get a new job.

                          BTW, did you notice the brace to the wall? Clearly set up for machining things that are out of balance. Not his first repair by far.

                          Not an observant Muslim..... Coffee and tobacco? Not per the law of the Prophet. But a good workman making use of what he has and can build.
                          4357 2773 5150 9120 9135 8645 1007 1190 2133 9120 5942

                          Keep eye on ball.
                          Hashim Khan

                          Everything not impossible is compulsory

                          "There's no pleasing these serpents"......Lewis Carroll

                          Comment


                          • #14
                            Originally posted by A.K. Boomer View Post

                            Willy - i respect your opinion - I am always amazed that the resourcefulness and also the SKILL of these types of hard working people,

                            In fact id put this guy in the same category of the people building axles out of chain links! amazing to say the least, but high quality axles? not a chance --- I did watch that entire vid - again amazing - but totally crude axles and who knows about the steel, the guide hole's were drilled on a drill press with a worn out guide hub, the bit's were wobbling all around - the holes are of course totally out of wack but "close enough for lugs" well in away but some will be crooked due to being off pattern and then having to get sucked up against the properly machined and spaces wheel so they will be under great stress in area's and fail prematurely ---

                            that's just the tip of the iceberg,,, and with the cranks? name of the game is they all have to flex as a unit, they will most likely fail right where the weld meets the crank material, the harmonics/frequencies/vibrations just in running will catch up to it let alone power strokes and like I said good chance of taking out an engine block or locking whatever vehicles drivetrain up around one of those cliff hanger roads it's probably going to be on... count me out - again totally amazing - but I cannot applaud - sorry....
                            Like I said watch this video, not talking axles from chain links, don't paint everyone with the same brush, totally different people and circumstances.

                            A closed mind is a sad state of affairs, it means I already know everything so don't confuse me with facts to the contrary. So sad, too bad.
                            May as well not read anything here anymore.

                            Oh well buddy in the video is getting paid everyday by putting out his services that appear to be viable choice for his customers, and yes he's not catering to the F1 crowd. You may not need him but his customers obviously knock on his shop's door as they need a crankshaft for their truck or tractor so that they can eat.
                            They aren't looking at or for bleeding edge technology, they just need to get back in the saddle. Much to be learned here.

                            Not everyone is blessed enough to live in a perfect world, suck it up princess, it doesn't always need to be.
                            Home, down in the valley behind the Red Angus
                            Bad Decisions Make Good Stories​

                            Location: British Columbia

                            Comment


                            • #15
                              Originally posted by Willy View Post

                              Like I said watch this video, not talking axles from chain links, don't paint everyone with the same brush, totally different people and circumstances.

                              A closed mind is a sad state of affairs, it means I already know everything so don't confuse me with facts to the contrary. So sad, too bad.
                              May as well not read anything here anymore.

                              Oh well buddy in the video is getting paid everyday by putting out his services that appear to be viable choice for his customers, and yes he's not catering to the F1 crowd. You may not need him but his customers obviously knock on his shop's door as they need a crankshaft for their truck or tractor so that they can eat.
                              They aren't looking at or for bleeding edge technology, they just need to get back in the saddle. Much to be learned here.

                              Not everyone is blessed enough to live in a perfect world, suck it up princess, it doesn't always need to be.
                              Like I said - limited resources and tons of time can make anything look viable I guess, and your right we are all spoiled that way, all's I can say is yeah grateful I don't need to go that route....


                              Hey - got some other vids for you to watch --- there's people growing vegetables with their own feces --- Sounds crazy but other people are lining up to buy them so they must be delicious (DUH)
                              Last edited by A.K. Boomer; 12-26-2021, 12:56 PM.

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