What is this hole?

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bigfoot72

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Oct 8, 2014
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Location
Seattle, WA
My Car
1972 Ford Mustang Coupe
I found this hole when i took off the intake manifold recently. It doesn't look like the factory cut it out and i'm wondering what this could be or how it happened. I also discovered a few fragments around the area as you can see in the picture. 

Anyone have any explanations? 

Thank You

image1.jpg

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If I remember correctly my block was the same. Tried looking for pictures from my build but didn't have any of that area. Were the fragments metal, if so then you need to find out where they came from. I have another bare block in storage so if you don't get a definite answer I can go check it out.

 
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If I remember correctly my block was the same.  Tried looking for pictures from my build but didn't have any of that area.  Were the fragments metal, if so then you need to find out where they came from.  I have another bare block in storage so if you don't get a definite answer I can go check it out.
The fragments are not metal. I think they are part of the valve stem seals.

 
Supposed to be there. On every Cleveland block I've ever seen. Not sure why.
Hmm ok. Its weird because it doesn't look normal, but i guess if its on every block then it must be factory. I wonder what it's for then? Oil drainage maybe

 
Supposed to be there. On every Cleveland block I've ever seen. Not sure why.
Hmm ok. Its weird because it doesn't look normal, but i guess if its on every block then it must be factory. I wonder what it's for then? Oil drainage maybe
I think that its for oil drainage in case the smaller holes can't keep up or become plugged.

 
Supposed to be there. On every Cleveland block I've ever seen. Not sure why.
Hmm ok. Its weird because it doesn't look normal, but i guess if its on every block then it must be factory. I wonder what it's for then? Oil drainage maybe
I think that its for oil drainage in case the smaller holes can't keep up or become plugged.
Standard issue oil drain back hole/cam gear oiling. Came like that from the factory. Your block is fine.

 
Yep, you're fine. Here's a pic of a 302 Windsor block (well actually my coffee table in the living room) that has exactly the same hole.

IMG_8185.JPG

 
Yep, you're fine. Here's a pic of a 302 Windsor block (well actually my coffee table in the living room) that has exactly the same hole.
Well thats good to know! I thought there was something wrong in my block.

 
It's not for oil drainage. It's to promote proper crankcase ventilation.

 
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Yes, that hole is supposed to be there. If you look at the casting code on the block, I'm sure it will be D0AE-L.

It is not "bashed in" as has been suggested in other threads, with a FBH (f'n big hammer), but is cast in at the foundry. When the cores are assembled, a worker would place a small amount of sand in that area to create a rough hole in the block. I have done this "trick" in blow molding plastic prototype parts for the same effect. If you were to look at a "J" block, D0AE-J, you would see two holes cast in at the back end of the valley and these were for oil drainage and yes ventilation. The "L" block is a later engineering change and the rear holes eliminated, but instead of spending money on new or reworked cores, they obviously took the cheaper route.

below is a picture of my "L" block in assembly with 13cc dished pistons. (I thought I had a picture of a "J" block I had, but may have dumped it.)

Ok found the J block pics. Green circles show the rear holes, red shows the front "rough hole" that to be honest, I didn't realize was on this block as well, so the L block just had the rear holes eliminated.

 
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Yes, that hole is supposed to be there. If you look at the casting code on the block, I'm sure it will be D0AE-L.

It is not "bashed in" as has been suggested in other threads, with a FBH (f'n big hammer), but is cast in at the foundry. When the cores are assembled, a worker would place a small amount of sand in that area to create a rough hole in the block. I have done this "trick" in blow molding plastic prototype parts for the same effect. If you were to look at a "J" block, D0AE-J, you would see two holes cast in at the back end of the valley and these were for oil drainage and yes ventilation. The "L" block is a later engineering change and the rear holes eliminated, but instead of spending money on new or reworked cores, they obviously took the cheaper route.

below is a picture of my "L" block in assembly with 13cc dished pistons. (I thought I had a picture of a "J" block I had, but may have dumped it.)

Ok found the J block pics. Green circles show the rear holes, red shows the front "rough hole" that to be honest, I didn't realize was on this block as well, so the L block just had the rear holes eliminated.
Wow that was a very thorough explanation. Thank you very much, that makes so much more sense now!

 
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