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Blown motor

Motor is in and we're back on the road.Will be hitting the beach soon after break-in. The swap went nice and easy with only the weather not cooperating. Had to work under a tent because the truck won't fit in the garage. Also installed an ORD twin stick to my 203 while it was out.
Opened up the old motor and discoverd that the crank snapped in half, not a wrist pin as I thought. How it still ran and moved under its own power is a mystery.
 
Good deal. I'm interested to hear about much felt power you gained after you get it broke in.
 
Did it snap under a bearing cap?
We had a forklift at the plant that ran most of the summer with a knock. Finally got a chance during the off season to pull the motor and replace the bearing or wrist pin or whatever.
Turned out the crank had snapped midway in a main bearing journal. The two half ends were sloped, so they turned together, the bearing and cap held them in place, and the darn thing just kept running.
If it had snapped square, the front half of the engine would not have turned.
 
I was just reading up on how newer motor oils are missing zinc and causing a lot of older flat tappet cam failures. Don't know enough about them to know if that could cause it to break, but something to think about with your new engine.
 
I did'nt have the time to open it up yet, but when I grabbed the balancer it moved in all directions and could here it rattle around. I can't tell were it cracked exactly from what I can see .
 
Madness! Did your accessories quit moving too? Or was the crank still attached enough to keep them spinning?
 
Have the same kinda motor issue...just haven't opened her up to look see.
I have a 4wd pop top on the 79 so i guess its time to make some hard choices
in what direction to go.
 
y5mgisi said:
Madness! Did your accessories quit moving too? Or was the crank still attached enough to keep them spinning?
Click to expand...

The engine won't run if the front of the crank doesn't turn (timing chain makes cam move, cam makes distributor move, I think you get the idea).
 
Everything was spinning,even had oil pressure. Made a sh*tlload of noise though, like tummbling boulders in the dryer.
 
Did the same thing to a HO 455 pontiac years ago,and that was a steel crank!! Thing would idle and rev just made a LOT of noise!! See ya out there!
 
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