How do you recover from a blown piston?

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It has to come down. Bore at the very least and possibly a sleeve. Throw it under the bench and build something 360 based. You don't want that original 340 hurt any worse.
 
RustyRatRod said:
It has to come down. Bore at the very least and possibly a sleeve. Throw it under the bench and build something 360 based. You don't want that original 340 hurt any worse.
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Good advice. ^^^^^^
 
Signs of severe detonation, extra heat in the cylinder, ring-ends butted together and starting to bind in the cylinder.
But before that could happen the piston-top broke away because of the ring-drag and gave the rings the extra room to crack and relieve tension.

Do the other pistons also shown signs of detonation?
 
Like the others have said detonation caused this.

Hopefully that is just aluminum stuck to the cylinder wall.

That engine has to come completely apart.

You may get away with a cylinder hone , but you won't know until the machine shop gets the block

good luck
 
RustyRatRod said:
It has to come down. Bore at the very least and possibly a sleeve. Throw it under the bench and build something 360 based. You don't want that original 340 hurt any worse.
Click to expand...
Yes , happened t my 440 six pac , had to sleeve 2 cylinders . But don't throw it under a bench , run it after it's rebuilt , no reason it should be hurt . I ran my 440 for over 150,000 miles after rebuilding it .
Good luck .
 
Ouch! Doesn't look good. Show your photos to the machine shop and see what they say. They should be able to tell whether it's worth messing with or not. tmm
 
Remember to closely check the other 7 pistons, rings and rods for signs of problems before deciding what to do.
 
If a sleeve is in order, consider a heavy duty sleeve. We just lost a cylinder that had been sleeved on the cheap. We're running 11:50's. The sleeve couldn't take the pressure, hydrolocked, split, ruined piston, 2 rods, scored crank. All fixed now, running 10:97 with good air. Cheap parts DON,T WORK Tom
 
I am going to agree with Mad Dart, that looks like a severe case of detonation due to a severe lean condition. Better get that checked out after the engine is back together again, or it will be "de ja vu"!
 
Lean and combined with lots of advance at that moment ==> detonation. It might have gone lean with the quick off-the-on throttle situation upsetting the carb..... and if the RPM's were up the full mech advance would be in. Shouldn't do it though, so something should be changed in the engine next time to be less aggressive.
 
It's hard to tell but that ring looks intact and were looking at it's gap in the pics. Pictures can lie and for all I can see that just looks like alloy deposits attached to the bore . What's the intended use of the engine? If you can remove the deposits and clean it up with a hone or wet and dry paper ( if your tight assed) and it's a daily driver, then you might get away with it. I've see worse go back together with the exact same thing, as well as the piston being welded up and re used..Yeah I know....
 
It's a numbers matchin 73 340 4 speed Road Runner. That's why I recommended throwin it under the bench. He has probably enough stuff to build a 360 based engine.....or four.
 
Ok , that sounds like a better idea Rod. You want to keep that engine safe.
 
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