I've owned my car now for 10 years, and in all the time that I've owned it I've NEVER been this frustrated with it. Here's my problem:
About two months ago I replaced my old engine with a new one. The specs for the new engine are as follows: stock 440 block (.055” over), stock forged crank, no-name aftermarket H-beam rods (w/ 7/16” bolts), KB forged pistons, Indy SR OOTB (gasket port), Indy 2D Intake, 850 cfm Holley DP, 440 Source roller rockers, TTI 2 1/8” headers & 3" exhaust, Pro Comp dist., 7 qt. pan, .520”/.550” lift, 242/252 (.050”) and 310/320 duration hydraulic flat-tappet cam. The compression ratio is about 11.5:1 and I run a race gas mixture.
The top end of my old engine was the same (except for the cam) and I used the same 440 Source starter and B&M converter (3200 stall) that I had with my old set-up. While I was moving the distributor from one engine to the next, I noticed that the rotor needed to be replaced and that the anode coming from the coil was missing (I guess the spring that was behind it had been serving as the new anode for a while). I replaced the cap and rotor and also bought 4 straight high-heat boots for the 4 cylinders at the rear of the engine that were near the headers.

Everything seemed fine until one day, while trying to get the timing in, my starter sheered off a half dozen teeth from my ring gear on my converter (it's a 727 car). I dropped the transmission, sent the converter away to have a new gear welded on and put it back in. I fired up the engine and - TA-DAH! - off come a dozen teeth. Rinse, repeat.
So now I'm on new ring gear #2 and I retarded the timing and this seemed to fix the problem (I'm at about 16 degrees initial). Yesterday I went into the garage to start it up, and when it fired I could hear that it was back-firing. I checked to make sure that all of the plug wires were good, and I fired it up again, only to hear the all-too-familiar sound of a tooth being sheered (why isn't the starter bendix softer than the gear teeth?). This time I was lucky: only a half a tooth is missing and I figure that I can take it to a welder and have them fix it without having to remove my transmission. Obviously, I'm scared to try and find the problem through trial-and-error at this point because I don't want to lose any more teeth in the process.
The problem is definitely in the ignition somewhere (and yes - I checked the firing order).
Has anyone ever had anything like this happen?
This is really frustrating and I appreciate any help that you can give!

If I don't get this thing figured out soon, you may be seeing a '68 Roadrunner on the "For Sale" board.

Sounds like the engagement of starter is possibly not too deep into teeth of ring gear, or the ring gear quality is a bit off. I used to turn locked chevs one tooth at a time with prybar, prying off of starter, and broke a starter nose that way, but never broke a ring gear tooth. It's odd that just a timing issue or a cross-misfire situation would be tearing up teeth. I'd be aggravated too.

so you are stating that the starter is not disingaging? that is what is shearing off the teeth correct? is it shimmed correctly?

put your timing back where it was, fix the ring gear teeth & get a new starter.

I've bought a new starter when I swapped out the last ring gear. The starter is definitely what's cutting off teeth. The starter/ring gear geometry shouldn't be any different than it was with my last engine (440 blocks are all basically the same). I didn't have to shim the last starter, and I didn't shim this one.
Again - I keep thinking that the problem lies in ignition...

The starter bolts to the trans anyway. I wonder if both the block dowel pins are in place? did you notice?

pull the starter teeth forward into the ring gear teeth & as said visually check the amt of engagement & see if anything looks off. The starter gear needs to be forward enough for full engagement and the in/out(sideways) distance needs to be good also

They were in place.

After a good inspection of everything as suggested. I would spin the engine without ignition, and make sure the starter spins it right. If it does, I would suspect a possible problem in the distrbutor. Have it tested, or better yet, try another distributor.

Sucks that this only started happening after 10 years of no problems. Did you consider running a coil kill switch or a solenoid jumper momentary button? That way you could either crank with the key and then turn on the spark when its spinning good, or crank with the button and turn on the key when its spinning good. Mine is set up the second way, with no spinning from the key. More of a theft thing than a starting thing for me, but it is a cheap way to start good with locked out timing and it could possibly solve your problem?

Good luck!

What kind of ignition are you running?

Check your cam timing. damhik

I'm running a Pro Comp distributor and a stock-style coil. As I mentioned, I recently replaced the cap and rotor.
The cam was installed "straight up" just a few weeks ago. I checked to make sure that it wasn't off several times.

I've had ignition and starter problems before. In my case I was breaking starters on a regular basis, the nose would crack and open then no more starter. I never hurt the ring gear. Let us know what you find out, your problem makes mine look simple.

Robert

The big block single bolt ( for mounting cam gear ) have been known to not hold well enough, especially on modified engines. The gear could have spun to some extent on the cam( sheared the woodruff key ). If you looked at the timing dots on the cam and crank, it would look like it was ok, but the cam would be in the wrong position. It could have seen extra stress when you were timing the engine. A backfire would be hard on it. If you have the three bolt cam gear, disregard this.

Thanks for the replies. The cam that I have is new as are the timing chain and the gears. Swapping the cam out wouldn't exactly be fun (it involves pulling the heads since I have Indy SRs), so I'm really hoping that that isn't it.
If I have the #1 piston at TDC, how exactly do I check to make sure that the cam is correctly timed?
Thanks in advance.