General Cylinder Head Question

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Grumpyoldman

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On the intake face of each head is a "half moon" (upside down smiley face) slot around the "heat hole". I have never heard a logical explanation for the purpose of the "half moon" (upside down smiley face) slot.

Can someone shed some light on this subject for an old fart.

Can it be pugged, should it be plugged? Ifthose of you have plugged it, why did you chose to do so, how did you do it and was it successful?

The heat hole, I have heard various versions of plugging those, but none seem to be truly successful and some seemed to be possibly capable of failing and causing damage.

I have no intention at present of plugging either one. Just wanting to satisfy my curiosity. If there is a benefit for doing either or both, perhaps I would consider doing so.

Thanks
 
What you talking about Willis...?..
Picture..??...
A picture should not be necessary. Just look at the center of the intake face any small block cylinder head and they are readily apparent. The heat hole was designed, I believe, to transfer heat to the intake manifold. That hole I understand, but aftermarket intake manifolds have no provision for the heat transfer, so it of no use for our purposes. The "slot" that surrounds it on the top, left and right is the one that seems to confuse me. Have i made it worse?

Besides, I have absolutely no idea how to post a picture, even if i had one to post.
 
The smiley face around the heat hole is an air space around the Heat Hole to help disipate the heat from going into the head from the hot exhaust gasses passing through the heat hole.

Don't think it is a good idea to block those off.

Here is a picture of the heat holes and smiley faces around them on these heads.

1020161100.jpg
 
A picture should not be necessary. Just look at the center of the intake face any small block cylinder head and they are readily apparent. The heat hole was designed, I believe, to transfer heat to the intake manifold. That hole I understand, but aftermarket intake manifolds have no provision for the heat transfer, so it of no use for our purposes. The "slot" that surrounds it on the top, left and right is the one that seems to confuse me. Have i made it worse?

Besides, I have absolutely no idea how to post a picture, even if i had one to post.

Ignore J Par. He's a moron sometimes, but he means well. lol

That half moon is basically a heat sink for the heat crossover, so air can get to it somewhat and cool it to keep the cast iron from cracking there. Nothing installs over it, it is exposed normally. Simply assemble as normal. Everything is fine.
 
Ignore J Par. He's a moron sometimes, but he means well. lol

That half moon is basically a heat sink for the heat crossover, so air can get to it somewhat and cool it to keep the cast iron from cracking there. Nothing installs over it, it is exposed normally. Simply assemble as normal. Everything is fine.
ignore Jpar? but do what I say which is actually what J Par said: redisassemble it and act like it's not there?..
Edit: hitting the ignore, I can't argue about something so simple....
 
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The heat cross over is what you're speaking of, it has a half moon recess around it... to cool it. Unlike the exhaust manifold, not much air passes over it.
You need do nothing with it. The actual exh passage you can block if you want to pick up a little bit of power. Heat in the intake sucks really...
 
ignore Jpar? but do what I say which is actually what J Par said: redisassemble it and act like it's not there?..
Edit: hitting the ignore, I can't argue about something so simple....

hush up fool. lol
 
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