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Fabricating an impossible to find oil tank for a motorcycle

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  • You might try dry ice to blast with. Should be no clean up.

    Hal

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    • Originally posted by Hal View Post
      You might try dry ice to blast with. Should be no clean up.

      Hal
      Thanks for the suggestion Hal. It sounds quite clever, and doable.

      Unfortunately, with all the things that I have on my plate, I likely will never get to doing it for the sake of trying it.

      However, if a specific need surfaces, now that I have it in my memory bank, it might prove invaluable!


      Best wishes to ya’ll.

      Sincerely,

      Jim

      "To invent you need a good imagination and a pile of junk" - Thomas Edison

      "I've always wanted to get a job as a procrastinator but I keep putting off going out to find one so I guess I'll never realize my life's dream. Frustrating!" - Me

      Location: Bustling N.E. Arizona

      Comment


      • Hi Everyone,

        Sooo, I started assembling the magneto and ran into another snag.



        The breaker plate on the right is typical of what happens when a hammer mechanic tries to disassemble one of these w/o knowing how to properly do it. The rotor drives top the needle bearing right through the very thin wall. I can't even remember how many of these I have seen back in the day. I thought I'd use the one on the left and bore it out to replace the bushing.

        Turns out that the bushing style is slightly thinner and would not accept the thin washer/retainer below the bearing as shown below in the aftermarket one I ordered:



        Just for grins I spun the mag rotor as shown w/o the points or condenser and I could get a healthy shock off the coil. YAY!



        While waiting, I have started on the oil pump:



        Lucky for me I still have the fixture I made for modifying these pumps almost 50 years ago.

        See.........., being a packrat pays off sometimes!



        To increase the scavenging capacity I have installed thicker gears and bored the cavity to suit:



        This shows the difference:



        Next was the enlarging of the oil passages in and out of the gear cavity. Same fixture set up on my rotary table in the mill:



        This shows the completed mill work:



        Some of you might have noticed that the mill setup was before the cavity was deepened. That's because I was in a bit of a hurry to use my spiffy rotary table. I used to do these by hand, cranking both table handles to follow the curved section.

        Sooooo, I ended up having to deepen these passages again after I deepened the cavity.

        DUH!
        Last edited by jhe.1973; 12-22-2020, 02:32 AM.
        Best wishes to ya’ll.

        Sincerely,

        Jim

        "To invent you need a good imagination and a pile of junk" - Thomas Edison

        "I've always wanted to get a job as a procrastinator but I keep putting off going out to find one so I guess I'll never realize my life's dream. Frustrating!" - Me

        Location: Bustling N.E. Arizona

        Comment


        • I used to work for a company that made test stands for hydraulic pumps, motors, and other things. They supplied most of the major manufacturers all over the world. One of the little esoteric tidbits of learning, was that gear pumps and motors are customarily made with a tiny interference fit between the gears and the cavity. The first operation on the test stand rotates the pump with oil supplied and shaves that last little bit out of the cavities for the best possible fit. And of course on the test stand the first place the oil goes next is through a strainer and then huge filters to collect all the swarf before returning to the reservoir. Pumps are tested 100 percent, not just sampled for QC since the test stand is essentially the last machine of the assembly line.

          And the owner asked me once how I'd analyze the pressure changes from inlet to outlet in those spaces between the gear teeth. Hmm, never thought about that. You've got zero pressure on one end and maybe 2500 psi on the other. Apparently it's been analyzed, and as soon as a tooth closes the space with the housing at the inlet, the full 2500 pounds is telegraphed to that tooth space. Strange and interesting.

          I know that's only semi relevant since you have your experience building and modifying these oil pumps but maybe it adds to the stack of fluid power lore.
          .
          "People will occasionally stumble over the truth, but most of the time they will pick themselves up and carry on" : Winston Churchill

          Comment


          • Hi all,

            Did not come here for about a month, so, plenty more to read and peruse and marvel at....

            I have had a 1954 KHK for the past 33 years... I once degreed the cams... Well, the exhausts are 10 degrees off each others... Same timing, but one is offset to the other once timed on the engine (and one tooth equates to about 22 degrees...)

            So a lot more than the 2 degrees factory tolerance... After thinking about it, and noting that Harley rarely published street/road cam data, I came to the conclusion that this offset might be to do with counteracting the 45 degree cylinder offset which gives a bias towards the front cylinder as far as inlet is concerned... And the offset doesn't hamper the performance, that thing was frightening Sportsters owners and eventually went a shade over 121mph at the Bonneville Salt Flats

            On the anecdotal "this cannot be done"... a friend of mine in France, not long departed and sorely missed by all, did restore big old cars for museums... Once, mid 60s, a museum owner came to see him with a Bugatti heavy type 50 cylinder block mounted on a wheeled fixture with a view for my friend to go round high end foundries to make replicas. These type 50 blocks are one piece from the crank mid partition up to the top of the DOHC above the non separate head, cast iron 5 liters ( about 312 ci) straight 8 cylinders. What's more, crank is supported by nine bearings and they are also water cooled, one can imagine the shape of the cores... Well, he visited them but even the old guys in them old foundries kept pointing at some block areas saying "this cannot be done!!!"

            Bye for now, can't wait for the next instalment!!!

            Hope you all have a reasonable end of year and that the next one will be a wotta lotta betta!!!

            Patrick
            Last edited by thefrenchowl; 12-29-2020, 08:34 AM.
            Flat Head Forever

            https://web.archive.org/web/20160318....com/index.htm

            Comment


            • The Bugatti block story/question makes me wonder if it couldn't be done as a lost wax casting. Rather than a strict investment casting which would still have some of the limitations of the mold, a wax model could be built from any number of pieces and massaged as necessary.
              .
              "People will occasionally stumble over the truth, but most of the time they will pick themselves up and carry on" : Winston Churchill

              Comment


              • From what I can remember, 1960s endeavour and 1970s discussion, the problem was more how to make the huge quantity of molten cast iron flow to all the intricate locations/recesses without air bubbles, misses, flashes and such...

                I can also hazard a fair guess that even at the time when Bugatti made them, there was probably more than 75% reject (1 right when 4 cast)!!!

                Patrick
                Flat Head Forever

                https://web.archive.org/web/20160318....com/index.htm

                Comment


                • Originally posted by TGTool View Post
                  I used to work for a company that made test stands for hydraulic pumps, motors, and other things. They supplied most of the major manufacturers all over the world. One of the little esoteric tidbits of learning, was that gear pumps and motors are customarily made with a tiny interference fit between the gears and the cavity. The first operation on the test stand rotates the pump with oil supplied and shaves that last little bit out of the cavities for the best possible fit. And of course on the test stand the first place the oil goes next is through a strainer and then huge filters to collect all the swarf before returning to the reservoir. Pumps are tested 100 percent, not just sampled for QC since the test stand is essentially the last machine of the assembly line.

                  And the owner asked me once how I'd analyze the pressure changes from inlet to outlet in those spaces between the gear teeth. Hmm, never thought about that. You've got zero pressure on one end and maybe 2500 psi on the other. Apparently it's been analyzed, and as soon as a tooth closes the space with the housing at the inlet, the full 2500 pounds is telegraphed to that tooth space. Strange and interesting.

                  I know that's only semi relevant since you have your experience building and modifying these oil pumps but maybe it adds to the stack of fluid power lore.
                  Thanks TG,

                  I appreciate hearing of your experience and feel that its more than semi relevant, since I was to be mentioning the need to closely watch the clearance between the gear faces and the housing and cover. Even though this clearance is minimal (little volume) the thin film still transfers pressure, as you mention, to the tooth spaces.

                  With the H-D pump, the volume on the scavenge side is more important than pressure, so keeping the side clearance tiny helps minimize oil washing over and under the gears.

                  According to the Sportster service manual, the pressure side of the pump is only 5 to 15 PSI at 60 MPH with the engine warmed to operating temperature. This is with a 1/2 speed pump and the racing one is a 1/4 speed.

                  I just received the part I need to complete the magneto and will jump back to that. I also want to have an additional discussion about this pump with my former supervisor so I'll be back here soon.
                  Best wishes to ya’ll.

                  Sincerely,

                  Jim

                  "To invent you need a good imagination and a pile of junk" - Thomas Edison

                  "I've always wanted to get a job as a procrastinator but I keep putting off going out to find one so I guess I'll never realize my life's dream. Frustrating!" - Me

                  Location: Bustling N.E. Arizona

                  Comment


                  • I had a Jaguar 3.4 sedan once that would never make more than 15 psi warmed up on the highway. It was a little nerve wracking but it never failed. That finally turned out to be a crack in one of the rotors. Sufficient bearing clearances all around to keep the oil film I suppose.
                    .
                    "People will occasionally stumble over the truth, but most of the time they will pick themselves up and carry on" : Winston Churchill

                    Comment


                    • Hi Everyone,

                      Lots of, "Three steps forward and one step back" progress since my last posting. I'm finding one of my biggest problems is keeping track of it all even though I save the photos from each day in a dated folder.

                      My next oil pump steps were to smooth the return oil path as much as possible by relieving any right angle bends with a carbide rotary file in a hand grinder:









                      You can see that I plugged the circular passage around the left gear.

                      This hole goes upward through the central pressure passage drilled from front to back and continues up to the cam chamber. There is a low pressure check valve in the central passage that keeps the pressure low but diverts excess volume to the cam chamber and to the inlet side of the scavenge pump. Because there is a plug in the cam cover to restrict oil to the connecting rods excess oil should keep this circular passage full and oil draining. At least that is the theory.

                      What I don't like about this idea is that there are two supply lines to one scavenge pump and if one sucks the slightest amount of air, ALL oil flow stops. I feel it is much better to direct all excess oil from the pressure side to the cam chamber where the larger openings that I have shown should help the cam side stay clear. I actually would prefer to divert any excess oil back to the tank, or have a much smaller pressure pump.

                      This basic pump design is a holdover from the 45 solo and servi-car used for decades. The 45 had a separate pressure pump driven by the rear exhaust cam and I think that was a better, though not as streamlined, idea.

                      I never came across these half round retainers for the pump drive gear and didn't feel like paying postage and waiting for them to arrive so I made them:



                      Because photos of set-ups have been requested I'll show a few of those in the next post.



                      Last edited by jhe.1973; 01-22-2021, 02:46 AM.
                      Best wishes to ya’ll.

                      Sincerely,

                      Jim

                      "To invent you need a good imagination and a pile of junk" - Thomas Edison

                      "I've always wanted to get a job as a procrastinator but I keep putting off going out to find one so I guess I'll never realize my life's dream. Frustrating!" - Me

                      Location: Bustling N.E. Arizona

                      Comment


                      • So, I simply made a washer with the correct diameters and cut it in half with the thin slitting saw;



                        To show the entire set-up and show off my favorite small vertical mill:



                        Next, grinding them to the correct thickness with lots of blocking to keep them from flying off the chuck:



                        It turned out that I had to reduce the O.D. a bit so I held them with an adapter I made to hold carbide inserts for boring, internal threading etc.:



                        Because the only covers I came across were for the later production oil pumps that used a thin snap ring instead of these keepers, I had to deepen the c-bore a bit:



                        I have a selection of used ball and roller bearings that I have accumulated through the years and often use their races as spacers for whatever. This was one "whatever".

                        More on the way...............................................
                        Best wishes to ya’ll.

                        Sincerely,

                        Jim

                        "To invent you need a good imagination and a pile of junk" - Thomas Edison

                        "I've always wanted to get a job as a procrastinator but I keep putting off going out to find one so I guess I'll never realize my life's dream. Frustrating!" - Me

                        Location: Bustling N.E. Arizona

                        Comment


                        • This is how a production cam cover looks with flanged bronze bushings instead of ball bearings of the racing version:



                          The race engines that are sold to the public use the bushings on the lower (crankshaft end) and the large one above and to the right of it.

                          The crankshaft end is referred to as the pinion shaft and it is possible to fit a needle bearing to it instead of the bushing. When making the sleeve a small oil seal can also be fitted:



                          However, if the sleeve is long enough to prevent the bearing from working its way down the hole, it will shut off oil to the crank which is frowned upon .

                          So, I needed to cut a path for the oil to flow behind this sleeve:



                          To clean out the oil hole after cutting the above relief, I had to remove the brass plug that restricts the flow:



                          I was SO glad I removed this plug became these were the burrs left from drilling the holes and pressing in the plug:



                          The head of the bushing is cutoff and allowed to float:



                          Still more coming............................................
                          Best wishes to ya’ll.

                          Sincerely,

                          Jim

                          "To invent you need a good imagination and a pile of junk" - Thomas Edison

                          "I've always wanted to get a job as a procrastinator but I keep putting off going out to find one so I guess I'll never realize my life's dream. Frustrating!" - Me

                          Location: Bustling N.E. Arizona

                          Comment


                          • Here's the completed cam cover with a bushing I had to make to support the magneto idler gear and the new brass restrictor plug:



                            When turning the engine with the cams in place I had two tighter spots near TDC of the rear cylinder and at TDC of the front. It turned out that the custom made gear that I had purchased was slightly eccentric. Plus the tooth tips were slightly too wide. Soooooo, I went back to an original idea I had at the start of this project in case I never found the correct gear.

                            There are two removable gears on standard Sportster cams that have the correct tooth shape and count so I made a hub for one of them:



                            After lightening it and welding in place:



                            Now it all turns great and all is right with the world!



                            Still more coming............................................ ............
                            Best wishes to ya’ll.

                            Sincerely,

                            Jim

                            "To invent you need a good imagination and a pile of junk" - Thomas Edison

                            "I've always wanted to get a job as a procrastinator but I keep putting off going out to find one so I guess I'll never realize my life's dream. Frustrating!" - Me

                            Location: Bustling N.E. Arizona

                            Comment


                            • For setting up the oil pump and breather timing I used a tool I made while in the Racing Department. I had to make several for the mechanics and I kept one for myself:



                              It is made to obtain the actual spacing that the cover provides, but obviously allows viewing of the gears. I found that the oil seal ring that I previously showed was too long and I had to shorten it a small amount:



                              The spec bulletin that H-D put out years ago has a standard oil pump timing method and one for use with a degree wheel. The degree wheel method shows that the breather shot should be enlarged on the closing side and this is what I was doing here:



                              The instructions for the degree wheel says to scribe lines on the above part and gear when the slot is just starting to open. I got lucky and this is how the lines met up at the correct crankshaft position:



                              So that brings me up to where I am at now. Starting to check cam timing:






                              Best wishes to ya’ll.

                              Sincerely,

                              Jim

                              "To invent you need a good imagination and a pile of junk" - Thomas Edison

                              "I've always wanted to get a job as a procrastinator but I keep putting off going out to find one so I guess I'll never realize my life's dream. Frustrating!" - Me

                              Location: Bustling N.E. Arizona

                              Comment


                              • Fascinating project, Jim, and great pics.

                                -js
                                There are no stupid questions. But there are lots of stupid answers. This is the internet.

                                Location: SF Bay Area

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