Trying to source/sort out starter on my 83 Ralt RT5. Hewland mk 9. Starter on car is a Bosch 0 001 157 023, with an alum adapter to bellhousing (right side of engine). Best I can count has 9 T. Searching it seems that it is from a BMW airhead motor cycle, 77-87?. Has 2 ears to bolt to adapter plate, with 2 other bolts into bellhousing for the adapter. Further found a "new" spare in parts about haft the Bosch size, with #18915N on tag. Tried that on and spins nicely but doesn't engage ring gear. Old starter will engage ring gear, but lacks omph to turn engine over with plugs loosely screwed in.... plugs out, it does spin over enough to build oil pressure.
Quick check on dimension between old one and "spare" appears almost the same, with then new spare having what appears to be permanent magnets, less weight, perhaps less projection/throw on bendix gear...but not by much...maybe .100-..150". Can't go thinner on adapter plate as no meat for threads to mount starter to it.
So, throwing this out to see if someone has better info on a starter setup for old SV/Mk9 with higher torque.... haven't looked into "special" high torque/reduction options, ala Twin Cam, FF, others, dubious of success on something this old/odd....don't want to get into inventing either... just spin the engine enough to start with plugs installed. (Had old FVC in a 212 years ago.... old Lucas starter that had to use 18v to crank....12 V to run...was a pain.)
This setup appears not using any VW/Audi/Car starter motors I've found, so far, via bosch p//n searches.
old starter appears rated at 0.7 KW.....see some permanent mag. jobs at 1.2Kw or better, so moving newer seems right direction....if I can get to engage ring gear!
Any guidance from "users" would be appreciated.
Bob L.