Triumph Stag - Bench testing a starter motor

Поділитися
Вставка
  • Опубліковано 7 лис 2024

КОМЕНТАРІ • 4

  • @KJs581
    @KJs581 3 місяці тому

    If stuck after sitting for a while, a screwdriver levered against the teeth will usually free it, but be careful of course. Then they will soemtimes just turn by hand, although need firm pressure, but usually some sort of lever will move them.
    The book says all Stags have a M418G starter...... I have a couple of spares here somewhere, but can't find them, I'll have to have a look tomorrow. But the point is, the one on my Stag, and the spare ones are all Lucas 2M100 starters, not M418G type. My Dolomite Sprint has an identical body marking, but the end cap is different, three mounting bolts from memory, rather than the Stags two. Judging by the book spec and measurements I have made, the 2M starter is less current/lighter duty, so strange they would do that, but is what my cars have.
    These are series induction motors, as the field is in series with the armature. The reason is that a series induction motor has greater torque as the load increases, so for our high load/low speed use, this type is far better than a shunt wound induction motor.
    Be careful testing starters, that is just "flash" them and run for a short time/not up to full speed. They aren't designed to run at high speed unloaded, and (apparently) can shed commutator segments. I haven't run one flat out long enough to find out.
    Just remember there are two large terminals and two small ones. The two small ones can be confusing, as they are usually referred to as "ignition" and "start". The start one goes to the "ignition switch" start connections to activate the solenoid. Wheras the "ignition" one goes to the coil, and puts full battery voltage onto the coil, but ONLY while cranking. When the car starts and the starter releases, that terminal becomes dead, and the car reverts to the 6 volt coil supply that is dropped by either a separate ballast resistor or (more usually) the resistance wire that is in the wiring loom.
    There are two separate solenoid windings, a "pull in" and a "hold on". The hold on is low current (17 amps), but the pull in, while only on for a fraction of a second, is very high at approx 80 amps, so I always back up ign switches with a relay. Those figures are for the M418G, the 2M is slightly lower.
    But you probably knew all that already. 🙂

    • @sujitroy
      @sujitroy  3 місяці тому +1

      Good info. and thanks for details. I charged the battery for an hour and I was able to test the starter and it ran. Only when its on the engine, will I know for sure. The starter I have is different to the one illustrated in my parts book.

    • @KJs581
      @KJs581 3 місяці тому

      @@sujitroy Hello mate. I found another vid of yours mentioning a relay, sorry for the "suck eggs" above.
      As I mentioned above, the books mention the M418G type mainly. That was used in only very early Stags apparently, and most have the 2M100 starter. I have a fair few Lucas parts lists, I think your email is on your home page here, if you don't mind an email, I can try and attach.
      It appears that Lucas replaced the M418 type with the 2M100 type in the early 70's across the board. While the M418 was a heavier starter, the 2M100 is a lighter, simpler (cheaper/less complex) starter, which was the way the industry was going.
      Examples are that the pivot pin for the M418 is a nicely engineered eccentric that can be adjusted to exact tolerance, wheras the pivot pin on the 2M100 is a "non adjustable pin with a spring clip" that holds it in, and end float for the 2M100 is set by the same sort of spring clip, which is a bit "cheap." All in all, the 2M type is a simpler/easier to make starter.
      The 418 generally draws a bit more current running, and torque figures are slightly higher than the 2M. For example, lock torque is 17 lb/ft @ 420 amps versus 14.4 lb/ft @ 463 amps respectively. But running @1,000 RPM figures are 8 lb/ft @320 amps versus 7.3 lb/ft @ 300 amps.
      The main difference is in the commutator arrangement, the M418 has the usual comm type with the "in from the side" brushes, wheras the 2M type has what they call a "face commutator", that is it faces the end of the starter, and brushes come in from the end. Also the M418 and is conventionally wired, that is current through fields then armature. Wheras (according to Lucas books) the 2M type has the current go through the armature and then the fields. Makes no difference, they are in series anyway, but handy to know if testing/dismantling, as otherwise were the wires go will confuse.
      Be careful with those numbers. The M418G and 2M100 are the TYPE, and cover hundreds of car configs. The actual part number (and there are Lucas AND Stanpart numbers) determine what actual starter it is; because two starters can be both the same type, but different part number as they can have different pinion, different end cap, etc etc. For example, both my Stag and Sprint are both 2M100's, but are not interchangeable, as totally different mounting lugs on end cap.
      The lucas overhaul notes says "do NOT undercut commutator segments" on 2M type. Undercutting mica after comm clean up is normal elec motor maint 101, but the end type comm is far thinner section than a standard one. I did mine, but was very careful/only undercut a fraction.
      Let me know if you want those part numbers and overhaul notes, I'll try and email them through.
      Cheers mate.

    • @sujitroy
      @sujitroy  3 місяці тому

      @@KJs581 Sure . Thanks. My email address is triumphstag@gmail.com