Starter bolt mount - not straight and not staggered? Huh?!!

[El Diablo]

Hi and thanks for reading...

I have a 1973 K10 with a 350, TH350. She's a project - body off resto.

I wanted to fire the engine just to make sure it DOES fire. Sorted some basic wiring. Solenoid noise only. Bit more investigation. Starter motor is 'Staggered' bolt pattern with a 14", 168 tooth flexplate... but only one bolt is holding it in place, plus a dodgey front bracket (non-standard).

I removed the starter motor and the block has two holes plus a molded 'dimple' it look slike, for a replacement starter motor. This neither a linear NOR staggered bolt pattern. What starter motor can I fit to this? Is this a really old block? Is it not a 350? I know the Small and Big block should have the same starter motor options so this one has me stumped? even checked for all types of starter motors (Chevy) on a Google Image Search, but I can't find anything that would have this style of mounting pattern?

I'll try to attach some pics. As you can see in one, the staggered pattern doesn't even have a hole in the block to mount to. The single bolt has (a long time ago by looks) broken some of the casting away from the nose, and the bolt itself was bent - which makes sense.

Any ideas from the GM Gurus????? Would love to stick a mini-hi torque in there - if I could find one that fits?

Cheers

 

[El Diablo]

Pics

Pic 1 - Bolt missing from starter motor
Pic 2 - Sorry! Turn your head to the left 90 degrees; now you're looking at the back of the solenoid and the second staggered bolt hole floating in the breeze
Pic 3 - Starter removed and you can see the bolt pattern that is almost longitudinal to the block, two bolt holes and one 'dimble' in the block casting?
Pic 4 - Starter removed and you can see the damage to the casting when overloading the single bolt receiver. Amazed that this EVER started the engine?!!

 

[El Diablo]

The 73 with an 82-83 body....

Replacing front clip to return to '73. Let's just get the engine running first though!!!

 

[robert8096]

Looks like the starter mounting portion of the block is missing. Should look like this.

 

[77 K20]

Looks like the starter mounting portion of the block is missing. Should look like this.

That is what I was thinking. The block sometimes can crack thru that last hole and maybe it ended up just breaking off.

 

[77 K20]

Perhaps a dumb idea- but I've heard of people using this to fix a broken block tab.

http://www.classicchevy.com/chevy-engine-starter-plate-kit-small-block-engine-to-turbohydra-matic-transmisison-1955-1957.html

You must be registered for see images

This adapter is for old small blocks that didn't have holes for the newer starters. After putting on this adapter you'd need to buy a '55 starter.

Maybe there is a better fix though...

 

[El Diablo]

Thanks...

Thanks guys.

Robert8096 - cheers for that. Makes sense from the pic. Bit of a bugger tho. Hard to find old blocks in the Middle East to replace it with. The suggestion from 77 K20 is appreciated too. I know you can get mini hi-torques for the '55s - maybe bolt one up to that adapter?

Initially I was hoping that was some unusual GM block and that an adapter would be available; but figuring that the two holes that I could see would never manage the torque of a starter? It was always a long shot. Wishful thinking.

I have a lead on a '92 454 with TBI (I think they had TBI). Figure maybe grab that engine and put a holley on it instead. Really wanted the 454 anyway, so it's maybe an option. engine and Trans Reconditioned - tho that could mean anything - seen some pretty dodgey stuff :-((

The final thing that I thought I MAY try, to salvage the 350, is manufacturing a bracket in 3mm steel plate to give starter something to hang onto. The torque reaction will try and pull the starter down and into the flex plate, so maybe fashioning a angled bracket that supports the starter (as a 'pad') and then attaches to the block above the starter, to counter the torque reaction.... well... that's where I'm at. I have the plasma and the Henrob torch. Steels cheap. If it works.... hell, maybe I'll chrome it )))

Is this failure so common? maybe there are already solutions? Ideas???

The '55 ring is a great start too.

Thanks

 

[robert8096]

Can't hurt to try a repair. Never seen a successful repair of the area. Seen a few tries but in the end it seems to either break again or throw the starter out of alignment with the flexplate/flywheel causing the ring gear teeth to be destroyed.

 

[77 K20]

I've heard the cracks usually happen from using the wrong bolt in that hole. Usually one too long since it isn't a thru hole.

 

[robert8096]

Also seen it from not using knurled starter bolts.

 

[El Diablo]

Cheers

That makes sense. I will try a repair. First repair will be a drill and tap to fit a mini hi-torque. If that does not work I'll go for the starter tranny mount kit and grab a starter from somewhere for that. It's a shame that this is a known issue but there's no aftermarket workaround that lets you keep the original starter? I may have some time to look into that too.

I'm going to pull the engine and gearbox. Make it easier to get to work on.

In the meantime I've managed to secure a reconditioned 454 from a '91 GMC Dually. Guy shipped the whole truck to my place last night. I get to pull the engine, plus 4-speed manual and transfer case, then send the rolling chassis back to him. US$1500 (equivalent) in receipts for parts and labor on the engine, plus a new flywheel and clutch - all purchased for $1500 if I pull it all my self. Yee hah!! Trucks running and driving so I'll zip around the block and see how she goes before the transplant. That'll leave the 350 and TH350 'on the bench' for a repair and use in a future project? Then I can come up with a bracket perhaps, to save the original starter motor, and manufacture a few for folks in the same predicament. Some RnD

 

[MadOgre]

I would just look for another block and quit wasting your time on this one. You can find a rebuilt short block real cheap sometimes. I once bought a completely rebuilt never started short block for $100

set it aside for future strip down of internals and what not.

 

[DoubleDingo]

I would just look for another block and quit wasting your time on this one. You can find a rebuilt short block real cheap sometimes. I once bought a completely rebuilt never started short block for $100

set it aside for future strip down of internals and what not.

May not be as readily available in the Middle East.

 

[El Diablo]

True...

Originally Posted by MadOgre View Post
I would just look for another block and quit wasting your time on this one. You can find a rebuilt short block real cheap sometimes. I once bought a completely rebuilt never started short block for $100

set it aside for future strip down of internals and what not.
May not be as readily available in the Middle East.



That's absolutely correct!. If it was just a matter of grabbing a new block, I would think that would be easier. If I had to ship one from the US it would only be feasible if it was a new motor - like a crate motor from Jegs or similar. That may still be an option down the track.

For now, I've pulled the engine, gearbox and transfer case - no mean feat given it's bumping on 120 degrees F and there's no shade!!!

Plan A - Mount the block on a stand, rotate, drill and Tap for (5/16 hole, for 3/8-16 thread and a 3/8s step for the knurled shoulder of the mount bolt. I'll keep posting pics 'cause this seems to affect a lot of people.

Plan B - fab a bracket that supports the rotational force of starter against a mount on the one of the trans-block bolts - preventing the outside edge (passenger's side) of the starter motor trying to climb down and bind on the flexplate.

Plan C - Work on the chassis and body work while a new engine ships over from the States????


BTW - Those ATV/Bike lifts are bloody handy when you're pulling the Transfer Case, or pulling the engine/trans on your own!!! Worth buying one if you don't have one for sure!!

 

[Georgeb]

What if you try to braze a coupling nut onto the broken ear of the block? It's really a long shot and it would take a lot of heat. probably warm the ear up first and then add the nut so you don't burn up the nut first. I know its kind-of a hack repair but it just may work!