Quote:
Originally Posted by funola
Ha ha this starter debate is never ending.  . FWIW a respected local starter rebuild shop told me that 616/617 turbo or NA starters are interchangeable. I have had starters from a 616, 617 turbo and 617 non turbo apart to steal parts from to put together a good starter and all the parts inside appears to be the same, i.e. they are not grossly different and are interchangeable. The starter that I cobbled up from used parts (I did replace the bushings and brushes and lubed everythig) is running perfect and cranks at 164 RPM per my phototach and starts my engine so fast it's incredible!
If you have a phototach and an ammeter, you can check out a starter on the bench (rpm and amps drawn) from Bosch specs. If it meet those specs, and there are no abnormal noise or smoke, and the bushings and brushes are good, slap that sucker in!
I think that theory of a 4 cyl and 5 cyl loads the starter 1 cyl at a time is flawed. At the very least, a 5 cyl has 1 more cyl and the cranshaft is longer and heavier so the starter has to work harder to move the extra weight so I don't know what the architect is thinking. My guess is Bosch made the decision to use the same starter for the 616 and 617 NA or Turbo engine because it is cheaper than to make different starters for each model. |
But as we all know the four cylinder was built first. In fact they built 3 cylinder versions of the same motor and I bet they used the same starter too.
It is true the five cylinder crank and flywheel are heavier and there is more drag from the parts rubbing but in the end all that is probably minor in comparison to the 21 to 1 compression ratio. I mean really, take away the compression and you can turn the crank pretty easily with your hands on the big pulley.
If you think the mb engineers just tossed the starter into the 300 motor without any knowledge of wheter it would perform satisfactorily for their customers who were paying $26,000 or more for a 300d when you could still buy a chevy for a third as much, I just think you are not thinking clearly.
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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.
[SIGPIC]
..I also have a 427 Cobra replica with an aluminum chassis.