2 destroyed starters in a row...WTH?

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Timing was 10 or 11*.

I checked the TDC with the balancer when the engine was new, but yes that should be checked again. In hindsight maybe I should have done that after the first failure.
 
Dusterdenovo said:
Timing was 10 or 11*.

I checked the TDC with the balancer when the engine was new, but yes that should be checked again. In hindsight maybe I should have done that after the first failure.
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I've mentioned it before, and maybe you've already done this, but when you are assembling an engine and you are dialing the cam in, or even just checking TDC marks, After you verified the timing marks on the dampener, you should match-mark the inner & outer rings, so it can easily be visually checked in just a minute, if not seconds, with no tools necessary.
 
rustycowll69 said:
After you verified the timing marks on the dampener, you should match-mark the inner & outer rings, so it can easily be visually checked in just a minute, if not seconds, with no tools necessary.
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That's a great idea. I will certainly be doing that sooner than later. Sounds like something that needs to be kept an eye on.
 
I think this may be caused by carbon buildup. The carbon gets hot and pre-ignites the fuel. You can pump the carb before starting it when it's hot and the fuel will cool down the carbon and prevent the pre-ignition. Then you won't have the engine fighting against the starter.
 
I've locked a motor up and the starter just clicked against it... Never blew one up before, so this is kinda new to me. Thanks for sharing.

My thoughts, is there any chance the gear is staying engaged ..? Are these factory ring gears?

Why do people buy power master or performance brand starters when the later factory one are not a only still 4.1 like the early ones.. but also mini sized?

I've been using the same one for 16 years, $25 out of the wrecking yard.

There is something going on, you would have to be cranking 220lbs to fight the starter with no retard.
 
I would also try a different distributor just for *****. it's a wacky idea , but maybe it's hanging up in full mechanical advance
 
Thanks for all the input guys. Lots of good ideas to focus on.

@MOPAROFFICIAL: they were both Hughes Performance Torque Converters. First one is only missing 1 tooth so I'll have to track down a good welder to do some dental work on that one once I get this all figured out.

This Covid thing sucks for picking up parts right now - the exchange rates suck worse then ever and I can't get across the border to my mailbox, so no free shipping to the lower 48 for me right now.
 
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Look at the witness marks on the starter shield. The starter has been moving. Are you sure you have the correct bolts?
 
RustyRatRod said:
Look at the witness marks on the starter shield. The starter has been moving. Are you sure you have the correct bolts?
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THIS^^^^^^^^^^ If the starter is moving around it will fracture the nose and then off it comes. I’m not sure why it’s getting the teeth on the converter but if the starter is moving into the ring gear rather than away from it it can knock a tooth or two off of it.
 
It sorta looks like the pilot in the bell is mangled.

The pilot-hole in my 1970 M/T bell,was too large to properly fit/support the pilot on my mini. I knew that could be trouble, with an 11.3Scr/185psi cranking pressure, so I installed Belville-type washers, on studs, and hoped for the best. That was 1999, and so far so good.... altho after the last teardown and cam swap in 2004, the pressure was reset to 10.95Scr/177psi.
Idle timing on my 367 is 14*
 
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RustyRatRod said:
Look at the witness marks on the starter shield. The starter has been moving. Are you sure you have the correct bolts?
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I agree, looks to me like the top was moving around. Since this is a stud are you sure it's actually tight and, not just running out of threads since it's not threaded all the way down? Are you getting it slightly cocked and tightening the bottom bolt all the way before tightening the top? I would think a misalignment situation would be the culprit..
 
AJ/FormS said:
It sorta looks like the pilot in the bell is mangled.
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The second picture in the OP showed the busted off nose of the locating cone still stuck in the bellhousing. Here is a pic of the pilot hole with that piece removed. Seems OK without getting right in there for a closer look.
20200602_131823.jpg


yellow rose said:
If the starter is moving around it will fracture the nose and then off it comes..
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RustyRatRod said:
Look at the witness marks on the starter shield. The starter has been moving. Are you sure you have the correct bolts?
Click to expand...

plymouth67 said:
Since this is a stud are you sure it's actually tight and, not just running out of threads since it's not threaded all the way down? Are you getting it slightly cocked and tightening the bottom bolt all the way before tightening the top?
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This is the hardware: both 7/16" threads. The top hole on the starter is clearly larger then 7/16", but I'm not aware of any bushing that is required and assumed that the pilot hole in the BH was "boss" as far as properly locating the starter. Hopefully that is the case?
100_8335.JPG


I'm confident that both starters were always tight; The top nut and bottom bolt were still nice and tight when I removed both busted starters. When installing the starters, I always tightened the top and bottom finger tight, then tightened them up evenly with the socket. I never reefed the hell out of them because of the Aluminum trans case but made sure they were good and tight. Before either failure, the secure mounting of the starter was double checked not so much to check for potential movement as to ensure that there was a good ground contact because occasionally the starters would be a bit sluggish when cranking which also seemed odd especially with the new Battery.

The stud was always buried in the BH, so I'm confident things were tightened up properly with sufficient threads available.

No arguing with the presence of the witness marks, but I would imagine that with all of the other damage due to the failures, it wouldn't be out of the question that the witness marks could have also been made at the same time - ie; more of the result then the cause?? Interesting to note that while the mounting surface of the first starter is quite smooth, the surface on the Powermaster piece is finished with very tiny concentric ridges - perhaps to provide better bite on the dust shield?

Hope this is helpful - all the input is appreciated.
 
How tight does the nose of the starter fit in the pilot in the bell housing?
 
I had exactly the same problem and broke two noses off of the mini starters. My issue was while cranking the distributor vac advance started advancing. Yes it was on the ported vacuum port. Weird as heck to find. Use your timing light while cranking and see if it is advancing while cranking. I made a full mechanical distributor and have not had a issue since. Hope it helps.
 
Dusterdenovo said:
The second picture in the OP showed the busted off nose of the locating cone still stuck in the bellhousing. Here is a pic of the pilot hole with that piece removed. Seems OK without getting right in there for a closer look.
View attachment 1715539363






This is the hardware: both 7/16" threads. The top hole on the starter is clearly larger then 7/16", but I'm not aware of any bushing that is required and assumed that the pilot hole in the BH was "boss" as far as properly locating the starter. Hopefully that is the case?
View attachment 1715539377

I'm confident that both starters were always tight; The top nut and bottom bolt were still nice and tight when I removed both busted starters. When installing the starters, I always tightened the top and bottom finger tight, then tightened them up evenly with the socket. I never reefed the hell out of them because of the Aluminum trans case but made sure they were good and tight. Before either failure, the secure mounting of the starter was double checked not so much to check for potential movement as to ensure that there was a good ground contact because occasionally the starters would be a bit sluggish when cranking which also seemed odd especially with the new Battery.

The stud was always buried in the BH, so I'm confident things were tightened up properly with sufficient threads available.

No arguing with the presence of the witness marks, but I would imagine that with all of the other damage due to the failures, it wouldn't be out of the question that the witness marks could have also been made at the same time - ie; more of the result then the cause?? Interesting to note that while the mounting surface of the first starter is quite smooth, the surface on the Powermaster piece is finished with very tiny concentric ridges - perhaps to provide better bite on the dust shield?

Hope this is helpful - all the input is appreciated.
Click to expand...


That top stud isn’t a straight shank like that. It should have a bigger diameter where is goes through the starter.
 
yellow rose said:
That top stud isn’t a straight shank like that. It should have a bigger diameter where is goes through the starter.
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I don't know one way or another, but they do make stepped studs, with different threads/diameters on either end. As far as general machining, you usually give 1/32" to 1/16" clearance on the fasteners, so whatever the diameter of the hole in the starter, subtract 0.032" to 0.063" from that should be dia of threaded fastener.
 
Bulldozer said:
I would also try a different distributor just for *****. it's a wacky idea , but maybe it's hanging up in full mechanical advance
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halifaxhops said:
I had exactly the same problem and broke two noses off of the mini starters. My issue was while cranking the distributor vac advance started advancing. Yes it was on the ported vacuum port. Weird as heck to find. Use your timing light while cranking and see if it is advancing while cranking. I made a full mechanical distributor and have not had a issue since. Hope it helps.
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After the 2nd failure, I've also been wondering what role the Distributor may have played in all of this - it could be one thing on the engine that was working properly then went south and started wrecking stuff. I will try and figure out if I can trouble shoot it some other way than checking the timing while cranking it - since things only seem to blow up when I'm cranking it. :eek:

Something I didn't mention earlier was that when the 2nd starter broke, the vacuum advance hose was removed and plugged (I was in the middle of checking the timing) so maybe @Bulldozer nailed it.

If I can't check the Diz on the bench, maybe I'll just replace it.

The above responses have given me a nice list to work through. Picked up a new Piston Stop yesterday, so I'll start with checking the Balancer and go from there.

Much thanks again, FABO!
 
This was a very very common problem back in the seventies because manufacturers figured out that they could retard the ignition and cam timing; richen the mixture, use an egr, and get the new cars to pass smog. Many a 350 chevy was getting 6-7 mpg in chevelles and novas. Carbon buildup was so bad that people had to shut their engines off in gear or they would just sit there and diesel. I saw some that would continue to run even while in gear. Back then everybody knew you had to pump the gas to start them even moreso hot than cold. They were clogging the cats right and left. Trick we learned quick was to put your hand over the exhaust and feel the pulsations to figure out if it was clogged with carbon; it it just felt like a blow dryer; it was bad. Starters and battery cables were frying like crazy. And they always made that sound; like the motor was fighting against itself to crank over; just like you stated. If you had an oxygen sensor it would be reading very rich. I bet you have to rev the motor sometimes to cure a rough idle. And I bet your plugs are black and sooty.
 
CudaFactHackJob said:
This was a very very common problem back in the seventies because manufacturers figured out that they could retard the ignition and cam timing; richen the mixture, use an egr, and get the new cars to pass smog. Many a 350 chevy was getting 6-7 mpg in chevelles and novas. Carbon buildup was so bad that people had to shut their engines off in gear or they would just sit there and diesel. I saw some that would continue to run even while in gear. Back then everybody knew you had to pump the gas to start them even moreso hot than cold. They were clogging the cats right and left. Trick we learned quick was to put your hand over the exhaust and feel the pulsations to figure out if it was clogged with carbon; it it just felt like a blow dryer; it was bad. Starters and battery cables were frying like crazy. And they always made that sound; like the motor was fighting against itself to crank over; just like you stated. If you had an oxygen sensor it would be reading very rich. I bet you have to rev the motor sometimes to cure a rough idle. And I bet your plugs are black and sooty.
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You kind of lost me a bit - are you saying I should be looking at carbon buildup as the cause of the broken starters? I saw that in post 30 and at this point that thought makes as much sense as any other but what would be the cause of such buildup? I don't have an egr or cats to plug and I get 12 mpg. I don't have to rev it so it idles smoothly, but my plugs have been known to look sooty. So then what? I'm not sure what to take from this additional info. Thanks.
 
Dusterdenovo said:
The second picture in the OP showed the busted off nose of the locating cone still stuck in the bellhousing. Here is a pic of the pilot hole with that piece removed. Seems OK without getting right in there for a closer look.
View attachment 1715539363






This is the hardware: both 7/16" threads. The top hole on the starter is clearly larger then 7/16", but I'm not aware of any bushing that is required and assumed that the pilot hole in the BH was "boss" as far as properly locating the starter. Hopefully that is the case?
View attachment 1715539377

I'm confident that both starters were always tight; The top nut and bottom bolt were still nice and tight when I removed both busted starters. When installing the starters, I always tightened the top and bottom finger tight, then tightened them up evenly with the socket. I never reefed the hell out of them because of the Aluminum trans case but made sure they were good and tight. Before either failure, the secure mounting of the starter was double checked not so much to check for potential movement as to ensure that there was a good ground contact because occasionally the starters would be a bit sluggish when cranking which also seemed odd especially with the new Battery.

The stud was always buried in the BH, so I'm confident things were tightened up properly with sufficient threads available.

No arguing with the presence of the witness marks, but I would imagine that with all of the other damage due to the failures, it wouldn't be out of the question that the witness marks could have also been made at the same time - ie; more of the result then the cause?? Interesting to note that while the mounting surface of the first starter is quite smooth, the surface on the Powermaster piece is finished with very tiny concentric ridges - perhaps to provide better bite on the dust shield?

Hope this is helpful - all the input is appreciated.
Click to expand...

I'm not saying this to be argumentative, but the witness marks tell the story of the starter moving. That's solid evidence.
 
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