New place to burn a hole ina piston. No crack, just hole.

jlawles2

Member
Jan 27, 2010
966
6
18
Danbury, TX
I think if you can find a good UT guy he can measure the depth with ultrasound. Check with Pat McRat he may have an option since he does CMM. Might be able to CMM Ultrasound them and see the profile of the oil passage.
 

Awmiller

New member
Aug 10, 2021
2
0
1
This was my piston and the story behind it is my rocker shaft snapped in my head doing a WOT pull and after tearing it apart my valves we not opening at all on that cylinder. Not sure how that affected the piston exactly but that was when this occurred.
 

Leadfoot

Needs Bigger Tires!
Dec 27, 2006
846
10
18
45
Western MA
www.matpa.org
This was my piston and the story behind it is my rocker shaft snapped in my head doing a WOT pull and after tearing it apart my valves we not opening at all on that cylinder. Not sure how that affected the piston exactly but that was when this occurred.
If the valves were not opening and the injector was still firing, I don't think any piston would have survived...kind of impressed it wasn't worse.

Assuming the piston cracked, then came the hole, and that at least acted as a vent/breather...you may want to check to see if the rod in that cylinder is any shorter than the others.

And thanks for sharing.
 

Awmiller

New member
Aug 10, 2021
2
0
1
That's definitely impressive. How many pulls do you have on those? What caused the valves to stop opening?
They probably only had like 25 pulls on them. One of my rocker shaft bolts were pushed up and ripped the threads out of the head and broke the rocker shaft in the head in half so it was no longer bolted down so the valves were not operating at all.
 

juddski88

Freedom Diesel
Jul 1, 2008
4,417
18
38
Chesterfield, Mass.
How on earth did pressure get beneath the hold down bolt to begin with? Maybe the threads were stripped upon last install amd not noticed? I've seen shafts binding, bridges snapped, and rockers snapped, but a blown out hold down bolt and threads is a new one.
 

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