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Engine What’s that?

  • Thread starter Thread starter PonyGTrider
  • Start date Start date Aug 24, 2026

PonyGTrider

5 Year Member
Feb 27, 2019
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Aug 24, 2026
#1
  • Aug 24, 2026
  • #1
Hi all, can anyone guess what is this I found at the bottom of my 306 oil pan? It seems like a piece of lathe cutter but who knows…. And how it got there? The block was machined out about 16 - 17 years ago
 

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Noobz347

Stangnet Facilities Maint Tech... Er... Janitor
Admin Dude
Jan 4, 1985
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Aug 24, 2026
#2
  • Aug 24, 2026
  • #2
It looks like what is left of a woodruff key.

Is it ferrous? Will it stick to a magnet?
 
Reactions: keel, rednotch, DadLife0724 and 2 others

PonyGTrider

5 Year Member
Feb 27, 2019
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Aug 24, 2026
#3
  • Aug 24, 2026
  • #3
Noobz347 said:
It looks like what is left of a woodruff key.

Is it ferrous? Will it stick to a magnet?
Click to expand...
It is not a woodruff key. It is carbide but what is it doing in there?
 

DadLife0724

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Mar 22, 2024
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Cooperstown, PA
Aug 25, 2026
#4
  • Aug 25, 2026
  • #4
This has me curious, i thought woodruff key also, but you don't seem to think so. I asked Google out of curiosity, got a bunch of stangnet posts, but it gave me this too......
 

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PonyGTrider

5 Year Member
Feb 27, 2019
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Aug 25, 2026
#5
  • Aug 25, 2026
  • #5
DadLife0724 said:
This has me curious, i thought woodruff key also, but you don't seem to think so. I asked Google out of curiosity, got a bunch of stangnet posts, but it gave me this too......
Click to expand...
That definitely is not a woodruff key, it is a completely hardened material and looks extremely brittle like carbide. I don’t see it as apart of the engine, my timing set is a Cloyes kit has nothing like that. My oil pump failed sometime ago causing some scratches two on the crank so I took it to the shop to be polished, installed a new oil pump and reassembled everything and that piece wasn’t there. I don’t think I saw anything like that inside an oil pump, or is it???
 

keel

Active Member
Aug 23, 2020
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Aug 25, 2026
#6
  • Aug 25, 2026
  • #6
PonyGTrider said:
That definitely is not a woodruff key, it is a completely hardened material and looks extremely brittle like carbide.
Click to expand...
I agree that it looks like carbide. They would have used a mill and a fly cutter to machine your block when it was bored 0.030" over to a 306 and possibly to surface the deck and heads as well. Carbide fly cutters often have square shanks consistent with the shape and size of that piece.

So my best guess is that the machinist broke a tool while machining that block and a chunk of it ended up somewhere in the motor and just took a while to make its way down to the pan.
 
Reactions: DadLife0724, Noobz347 and PonyGTrider

PonyGTrider

5 Year Member
Feb 27, 2019
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Aug 25, 2026
#7
  • Aug 25, 2026
  • #7
keel said:
I agree that it looks like carbide. They would have used a mill and a fly cutter to machine your block when it was bored 0.030" over to a 306 and possibly to surface the deck and heads as well. Carbide fly cutters often have square shanks consistent with the shape and size of that piece.

So my best guess is that the machinist broke a tool while machining that block and a chunk of it ended up somewhere in the motor and just took a while to make its way down to the pan.
Click to expand...
I agree 100% and it is the most logical explanation I have three of those strong magnets from a hard drive underneath the oil pan and that broken piece was firmly stuck at the bottom of the pan
 
Reactions: DadLife0724

keel

Active Member
Aug 23, 2020
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Seattle, Wa
Aug 25, 2026
#8
  • Aug 25, 2026
  • #8
PonyGTrider said:
I agree 100% and it is the most logical explanation I have three of those strong magnets from a hard drive underneath the oil pan and that broken piece was firmly stuck at the bottom of the pan
Click to expand...
A lot of carbide is actually attracted to magnets despite containing zero or only tiny amounts of ferrous material, something that a lot of people don't know.
 
Reactions: DadLife0724 and PonyGTrider

PonyGTrider

5 Year Member
Feb 27, 2019
639
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Mexico
Aug 25, 2026
#9
  • Aug 25, 2026
  • #9
keel said:
A lot of carbide is actually attracted to magnets despite containing zero or only tiny amounts of ferrous material, something that a lot of people don't know.
Click to expand...
Yep this piece sticks on a magnet like any other steel. This engine’s rotation assembly was assembled at the machine shop so I guess they didn’t completely clean the block after machining it because after years of operation I found a small pile of cast iron chips on the lifter gallery, I’m surprised the whole thing didn’t blow up!
 
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