That one sounds like the starter pinion gear is only engaging about halfway into the flywheel teeth. Unless you've got the forearm strength of King Kong, it would be a good idea to use a long screwdriver as a lever and get the starter pinion engaged all the way. It's also a possibility you've got a flywheel for a 55-62 engine working against a 6 volt starter. That combination is terribly noisy because the teeth don't mesh properly. The 12 volt flywheel (late 1955-62) has 168 teeth. The 6 volt flywheel has 139.
Also, if you're trying to run a 12 volt starter on 6 volts, it will crank very slowly. A 12V starter against a 6V flywheel will also be noisy. Take the starter off the engine and clamp it to a workbench or hold it in a vise, then do a function test on it. If it still runs slowly with no load, I'll bet it's intended for a 12V engine. The quick way to identify a 12V starter is the diameter of the armature shaft, out where the gear sits. 12V starters have a 1/2" shaft- - - - -6V shafts are 5/8" in diameter.
Jerry
