Couple times in the past month had a slow crank on some cold starts and some warm restarts, kinda an odd combo. Did all the VOM readings on the battery and thought it's good but now battery 6 years old and not a big deal to change. Bill said i was living on borrowed time. Paid 94 bucks in 2017 for the best at NAPA, 154 the other day for the identical battery, I even weighed them. A couple minor wear/rust spots in the battery box, a POR touch up and done, nice fresh battery and install.
Nothing is that easy, jackstands and a creeper, and headers and, I don't need this.

Almost twenty years ago the original 305 starter gave up, 2004, the T56 and TES headers were on the car. Time for a mini starter to be installed, only 125 bucks for a new mini Hitachi from one of the venders of the day. Had it out a time or two adjusting, shimming the engagement depth of the bendix. It would just kiss, tick, the flywheel ring gear when the crankshaft's end play was forward in the block. More the PITA thing than a problem, most people would never know it was a problem.

I lived with that until the new engine went in, 2007, a new starter, lots of shimming so the new McLeod billet wheel and the new Dart block made ring gear engagement and backlash happy. That was all done before the engine went in the car, on the engine stand. Bought that new starter from another vender of day, it was only 100 bucks. Good starter, no noises, seem like all good to go.

Well in 2011 that combo of parts ended up taking teeth off the ring gear, My thinking was ring gear failure was ring's material's fault. So now time for a a new Ceramix On-Off switch clutch a 700 lb/ft-er, cut the flywheel, new ring gear installed on the McLeod wheel.
Now it's time to buy something better, tired of playing with starters, bought a Powermaster 9000.185 bucks, 2011, the fourth starter in less then 10 years,

Every thing is fine, for about 5 maybe 7 years, 10K mile, and one day, actually several times, the starter has a dead spot.
Now pull that starter out of the car, the PowerMaster, go back to the parts shelf and pull the two previous mini installed in this car and find one is exactly like the Powermaster, the 100 starter. Dissected both of them and found they were identical, only difference was price.
The PowerMaster commutator is junk, brushes junk, the reason for it's demise. The other identical mini has bad teeth on the pinion gear, commutator good, brushes good.
Marry the best of the two and reinstall a refurbished Powermaster 9000, until death do it part,2023.

Well now here in 2023 there are three mini apart on the bench and another round of what to do about a starter.
The commutator on both the PowerMaster and the sister are now junk, most of those two will go to the scrap pile, no need to keep junk anymore. I will reuse the bendix and mount from the PowerMaster on the new starter I'm building. The teeth on the PowerMaster pinion are the best and all three of the mini bendix are identical along with the solenoids, the best of three will go on the next starter.

The original 125 dollar mini installed in 2004 will be the new starter. I believe it is a the high tongue Hitachi because the armature is much longer and the commutator OD is MUCH larger and brushes are very good. The Power Master bendix would like to change the bearing behind the pinion but so far have been stymied by an internal snap ring. The PowerMaster bendix is the only choice to reuse

Some time was spent shopping a mini to see what is being sold for my engine. I've done a $100, a 125, and a 180 starter, next jump is more for a high torque today.
Performance info of starter is at times vague. You surmise it's compression ratio that guides torque production necessary so there is three kinda zones.
Lower, higher, outta here. We mostly fall into the hole between lower and higher. 10 ish where you can maybe get by with the lower end of torque output from a starter. That Powermaster was one of that category, and also that mirror of the PowerMaster.

Will get that old starter bought in 04 back for another round with a little TLC and a little time. Here's is it's duplicate in a PowerMaster 9004.
https://www.summitracing.com/parts/pwm-9004

It's not about the money it's about doing it, good parts are laying on the bench. This will be the fifth starter dance for this car. Hoping to get 5 years out of it, let's see, 77, this might be my last starter in this car, I hope.
Bob

As you said on the phone the other day "it's always something with this hobby" and I would agree. Hope you can come up with a good solution as I'll be paying attention. Not sure what I will get into with the new engine but it should be 10:1 which isn't much and I'll give the stock starter a try and see how it holds up. I've never heard much about aftermarket mini starters except they don't last long. Usually they are a necessity due to header and oil pan clearance so no other option and usually surrounded by lots of heat which as we all know is a killer to electronics so the poor little mini starter doesnt have much of a chance and setup for failure at reaching 30 years or more. Good luck and I'll follow along.

Didn't the Gen 2 LT1s use mini starters?

The GM LT1 mini is I believe the starter that everyone copied to sell the new line of aftermarket mini. The GM LT1 goes back 30 years.
Here's the GM LT1 mini they sell today. Most all the mini that look like this are a Hitachi 3.75:1 ratio. And i would think all, even the expensive GM mini, are now China, so all mini like this are, questionable.
https://www.summitracing.com/parts/nal-19433448

Here's the PowerMaster 9000
https://www.summitracing.com/parts/pwm-9000

Bob

Here is info on a reman one for a 1996 Camaro LT1 engine.

https://www.rockauto.com/en/moreinfo.php?pk=1797958&cc=1035931&pt=4152&jsn=1084&_nck=ZExt1ysfqhqWnq%2BEvUNdS3Txyey60IDtnjPWF5UU9J0BWQv7pvqZbh%2BYrdIIoJ2QvjAcW39YRTU02C77No248W9oPPOPBa0%2ByMrUiaYjGVdwQceOjej2TuRe8f1GOf47sMaJHuB2tqvqdSsnDMzZS%2BPFgkvTqkWLR%2B0G%2BQhB9gyAUw%2FqJiYxpYs0kI0sCaacAyplp5GVMWtqg9RTfUtiWIExz%2F0qXa2UmdcjNexSRvxKgZNWdKDRI8C3MY%2F8GpndqMWV54TQaG0hPiGhC4qvhoD%2Bx3F5YdJLWoDbu53KnXqhHNtZNem2%2FmtlJVX7A85W

Thanks Brent.
Starter at left is first mini and the one getting rebuilt and dropped back in. Center and right are identical starters,

Comparison of armatures, no comparison, left much stouter and already has three years of use, commutator much larger. Note the brushes and commutator on the failed one is enclosed in the cast alum housing. The larger armature has the brushes and commutator in the end bell where it may get more/better air/cooling.

All speculation as I'm just an old car guy, not an engineer. I do like trains through.
Bob

On Tues evening assembled the hodgepodge of parts from three mini starters and a rebuilt is now installed back on the engine. Cranking speed is much improved, starter just sounds really healthy again. I jumper cable tested it fifty times while it was sitting on a shop chair, BINGO. Happy happy, Install with the Hooker 2050 headers is not difficult, just PITA for an old guy on a creeper.

I ended up using the aluminum mount and the Bendix from the PowerMaster on this rebuild of my oldest mini. All three of the bendix I had are near identical. But one is just not like the other two, it's large driven gear tooth machining is different. Those tooth cuts have a blind end, the odd ball gear has more steel left on the end of the cut. I assume bling cut to help retain lube. That odd gear cut was on that PM bendix and the fact the pinion gear was the best of the three, and it was the bendix from the PowerMaster. Maybe the PowerMaster did use a couple better parts in them.

I used the PowerMaster aluminum mount on this rebuild. I knew that PM mount along with the PM bendix bolts right onto the rebuild in place of the mount and bendix. All three mounts and bendix appear near identical, or maybe are, didn't do any measuring, no need. But know the mount gets shimmed and the bendix get shimmed to setup a starter. The junk starter removed had no shims So it would, should, set the pinion depth and pinion backlash when duplicating that junk starter, the PM, that was removed a couple days ago. reuse the PM mount and bendix. That was the plan, new starter should be a bolt in.

I have a Lakewood scattershield for a bell housing, when it's installed there is no checking backlash or pinion depth.

After looking for the fix to the mini starter I find you need to buy up in terms of torque output when doing the Hitachi type mini starters. Most of the aftermarket offers a Hitachi mini, and basically in two versions. The two different armature define the types. What seems to happen is some how the powers to be can make the small armature in two torque outputs. That big armature rating also vary, just depends whose hype you believe. My thinking is the big armature is better and the mini just rebuilt, is the large armature type.

Shopping and purchasing a new starter, if necessary, this is what I would do, all three of these starters are the large armature.
PowerMaster 9004, Proform 66258, Allstar 80515. They are identical in appearance to what was rebuilt and installed in my car. There is a 50 price swing between those three, can't say you get what you pay for. Maybe buy all three and compare them if i every need to install another starter in the car. Send back the two starter you don't like. I've done that several times before. I sure hope this is my last, this was the #5 starter in my 32 years of owning it. May not be a record as such but five may be a contender.

Kinda glad this starter problem happened. A week ago had two mini taking up space on a shelf in the back corner of the shop, shared that space with some short sections of quality exhaust pipe, an HEI and CCC HEI, my coil spring compressors, was some Global LCA there, some brake line, lots of stuff you hide away until later. Now with the exception of saving one solenoid all the rest of those two mini starter took the short walk to the outdoors, the scrap pile.
Kinda a bucket list thing, kinda.

So, a brand new expensive battery, a rebuilt starter, a 4 core copper/brass rad refreshed, the Safeguard engine processor restored, autox in ten days.
Thinking only need to adjust a couple shocks settings and go beat on it for the day, a 100 miles away.
Bob

Bob, thanks for the educational post onstarters as I might need that info in the near future. Hope all the gremlins are out of the way and you can get some seat time.

You can dress the commutator strip by chucking the shaft in a drill press and holding a flat file against it. I just did that with my starter. The brushes were worn down to the holders and the commutator had deep grooves. It took a while to get it flat, but there is still plenty of copper left...and it works. It worked before I took it apart. I just removed the end cover to have a look and realized it desperately needed new brushes.

Marc, did you replace the bushings on each end too??

Leo from taking apart these three different company mini they all use a roller bearing on both ends of the armature and two roller bearings in the bendix. In the old days when we used to repair them big old Delco starters they had bushings.
Surprisingly between the three Mini there was 12 roller bearings and all were still in good condition and could be reused, surprising.

Marc the commutator on the armature I used was in very good condition with really no grooving from the brushes. The above pic was was as removed and not after the refacing of the commutator. The gear on the end is to large to put in a 1/2" drill chuck, a lathe would be needed to spin that armature. I just cleaned the copper with a 400 wet/dry and followed up with a 1000 grit doing the 1/2 contact area sanding wrap method, then washed with Brakleen to insure the space between segments was very clean.

The other day it was 95 degrees, had the car out for a several hours to test A/C and also to see how the starter behaved doing numerous hot soaks, hot restarts and it performed flawlessly.
Bob

Yes, I did replace both bushings. The journals on the commutator seemed to be worn undersized, but it worked just fine before I took it apart and it bench tested OK. I will see how well it works when I put it back in.