# Broken starter mount boss



## mysons69 (Mar 3, 2012)

Thanks to all who gave advice regarding our Muncie install. It was greatly appreciated. Now on to something much worse...

Attached are a couple of pictures of a broken starter mount boss. It is the boss at the lower left rear of the block where the outboard starter bolt (and bell housing) threads into. Unfortunately for us, it snapped off, as you can see. The 1st (1822) picture is with the broken piece kind of in place, the 2nd (1824) with it removed, the 3rd (1816) is the broken piece itself.

Has anyone heard of this happening on a Pontiac? I’ve found plenty of posts where it happened to a number of small block Chevy’s, and I think some LS1’s, but I haven’t found anything about our cars.

Either way, any opinions on whether this can be fixed or not? Right now, we're feeling pretty down about the prospect of being able to use this block. I can't think of too many worse scenarios at this point.

The only possibility I can come up with is welding, and I’ve always heard that welding cast iron is iffy at best.


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## Instg8ter (Sep 28, 2010)

had a hairline crack in one on chevy V-6 in my boat, gave the starter just enough play to shear off the bolt and theres no jacking up a boat to get at it, threw in the towel after it sheared off twice and got a new block.


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## Rukee (Feb 8, 2007)

There is an awesome local welding shop around here that has fixed a couple of broken blocks (junk yard engines in accidents) just like that. He'll V-grind out the crack then put a bolt in to keep the threads lined up, then weld it back up. Had zero issues after the repair. Might be worth calling a few welding shops to see if they'll tackle it.


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## mysons69 (Mar 3, 2012)

Yeah, I'm gonna do that. Want to check with a shop I use nearby, see if they know anyone they feel is capable.

What really sucks about this is that we were trying to get the car on the road so my son (and maybe me, just a little) could get some time in it before he goes away to college. I'm guessing the time-line is getting pushed back a bit right now.

In the meantime, anybody got a good 400 or 455 for sale cheap?


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## Instg8ter (Sep 28, 2010)

i have a clean Virgin 70' 400 block complete at the machine shop thats been inspected and could be put back together with new rings and bearings, and a 70' 455 block that will need an over bore. I am in Michigan, may go grab the block today and get it back to the shop. PM me if your interested and i can send pics when i get it back.


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## geeteeohguy (Feb 2, 2008)

Never seen that one before. In 35 years of working on these engines. The engine was either in a wreck, or too big a bolt was forced through the hole in the block. I think it could be pinned and welded, probably with the block out of the car, by the right person. That's what I'd try to do if the motor was in otherwise good shape. Me, I'd be tempted to drill in from the side, at an upward angle, and tap the new hole in the block. Bolt it ack together, and have it welded, too. You have nothing to lose...you're looking at a new block, anyway, if it can't be fixed. Good luck.


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## mysons69 (Mar 3, 2012)

The more I look at this thing, the more I wonder...

Would it maybe be better to lop off the entire boss and put new material in its place, possibly steel? Supposedly welding steel to iron isn't any more difficult than welding cast.

I figure, with the starter bolt hole and the bell housing hole, there isn't much material left on that broken piece. Add the brittleness of cast iron into the equation, and it seems the chances of successfully welding this piece back on, AND have it continue doing its job long term, is suspect at best.

Attached is a pic of a 455 block in that area. If what's left of the boss was cut along that ridge, and a steel block was attached (first drilled and tapped into the remaining block) then welded, the screw holes could be tapped as necessary. 

Of course, not having any experience in this area, I don't know if that's just a pipe dream or not.


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## Rukee (Feb 8, 2007)

I would think a good welder would be able to reattach the broken piece. If you try to add on other material keeping everything plumb, level, and true would be difficult.
You may have to remove the tranny so he can weld on both sides.


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## geeteeohguy (Feb 2, 2008)

The prospect of "lopping off" the piece in a true and square manner would require an endmill machine... with the block out of the car and in a fixture.....a saw wouldn't cut it flat enough. And if it were cut flat enough, can steel be welded to cast iron? I'm no welder, so I can't say. I think not, though. You could try to have it welded and stitched, or maybe you could explore your options and install a mini-starter, by simply drilling and tapping a new mounting hole inboard of the cracked area. Not all starters have the same base dimension...if you could bet one with a narrower base, whammo, you'd be in business with no worries and not much effort.


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## mysons69 (Mar 3, 2012)

Oh! geeteeohguy!
That is absolute, ****ing genius!:cheers

It may or may not work, but it's a perfect example of why it's a good idea to run things by other people. I'm obviously thinking of harebrained ideas, and not considering real possibilities.

I'm checking with RobbMC to see if he can make a starter nose that will fit.

Thanks for thinking straight.


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## ALKYGTO (Mar 29, 2010)

How about some JB Weld? I honestly think it's worth a shot and I've seen it used on some seriously crazy engine block breaks. If you and your son want to drive it and not pull then engine right away and you are going to replace it anyways why not? 

I've actually seen an engine (BB Chevy, go figure ) that had the entire motor mount broken out of the side of the block JB Welded and running in a Monster Truck. Wish I had photos but talked to the driver (Tom Meentz) of Maximum Destruction after I saw this on his truck and he said yes they had repaired his supercharged BB with JB Weld and it held up and held coolant. They had that stuff literally dripping off many places on his block and it held together so before "scrapping" that engine I would consider it. 

Is JB Weld the "perfect" fix? No, but in this instance I would certainly try it myself.


Now I'll put on my flamesuit. :shutme


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## geeteeohguy (Feb 2, 2008)

Wow, _that's_ sticking your neck out a mile, Alky, that's for sure. I've seen JB Weld work miracles, and seal up cracked blocks on the water jackets, etc. It seems to last forever. That said, I think the nature of this crack, and the huge torque load concentrated on that one little area, makes it a poor candidate for JB. There is just too much _load_ on this area, unlike a water jacket. And how would you get it IN there without breaking the whole thing off and making it worse? JMHO........


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## mysons69 (Mar 3, 2012)

You guys are a pisser! 
_"Now I'll put on my flamesuit"_. Gotta love it!

All due respect Alky, but there's no way JB would hold under that torque load. But I think you knew that already. I will agree with geetee on this one. 
BTW, RobbMC replied back to me (and I checked the starter vs block); doesn't look like there's enough room in the starter nose for a new hole, unless it was angled. Nice idea, though.

It turns out there a number of motor heads where I work (National Laboratory), and I've been getting opinions from some pretty smart folks (and you guys too!), including welders. 
I've also been given contact info for a few supposedly excellent machinist/welders, one of whom I've contacted already. Most everyone agrees that the repair may be difficult, but do-able.
So to me, its worth pulling the motor and bringing it wherever I have to go to get this fixed. First shot has to be the best shot, and its only labor, right? So that's what we'll be doing this weekend. arty:
I will of course take more pics and let everyone know the results. How could I not?

BTW, check this link out, especially bottom page 1. This isn't what happened exactly, but maybe it contributed? Who knows?
WTF is up with my starter!?!? - PY Online Forums


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