starter ring gear damage????

[nh911]

Hello,

I am Michael, the father convinced by his 17 year old that we could not pass up the only $5000 911SC. $2500 in parts and $1500 in labor and we are still not up and running. Had a prior Porsche mechanic pull the motor to do gaskets, exhaust, clutch, manifolds and I thought ring gear. Put in new starter and we get the same grind out of the start as before(half the time). Motor comes back out, new ring gear, same starter(slight wear from several grinds) Put motor back in and get three clean starts no noise. Next day go to start , awful grind noise and then the whirl of a non-engaging starter. Pull starter to find it has eaten many teeth of the ring gear and itself. Try new mechanic, have it apart, nothing looks odd but the bolts for the ring gear almost appear to have been getting hit by somethng. Doesn't seem like starter has that much room to move.

Any ideas would be great, thanks for any help in advance

[iamchappy]

My guess is it is the wrong starter, most models look similar and i have replaced rebuilt starters that were sold as the correct model and found out the hard way (starter ring destruction) that it wasn't.