Can someone explain this port please

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Boduke

Boduke

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Stock 73 318 with #2843675 heads.
Has edelbrock performer and running felpro 1243 intake gaskets. IntKe and gasket do not come up high enough to cover this Crescent shaped port and it looks wet inside. Thoughts?

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Water passage to underneath intake manifold, coolant warms intake manifold right underneath carburetor. Helps maintain uniform heat range to promote vaporization and atomization of fuel and air mixture. Also helps engine run from cold starts to running temperature.
 
The magic number is 212 degrees F, so says so Grumpy Jenkins.
 
The oval port underneath it is your exhaust crossover, it preheats the manifold plenum for cold weather starts/running; flow is controlled by the butterly valve on the exhaust manifold.
The crescent shaped port is just a thermal barrier surrounding the crossover, it leads nowhere and is open to atmosphere.
 
ch1ll said:
Water passage to underneath intake manifold, coolant warms intake manifold right underneath carburetor. Helps maintain uniform heat range to promote vaporization and atomization of fuel and air mixture. Also helps engine run from cold starts to running temperature.
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Sorry for the red X but that is totally wrong. No water goes through that port. Just hot air.
 
ch1ll said:
Water passage to underneath intake manifold, coolant warms intake manifold right underneath carburetor. Helps maintain uniform heat range to promote vaporization and atomization of fuel and air mixture. Also helps engine run from cold starts to running temperature.
Click to expand...
The only time that is a coolant passage is in the big block dash 3 heavy engines. All others it is the EXHAUST crossover.
 
Heat Riser passage. No water passes through here.

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Scody21 said:
I dig the valley tray. Does it seem to help keep the intake a little bit cooler?
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They do work, especially if you also block the heat crossovers- although if you're using an Air Gap type manifold, they become somewhat redundant.
 
The tray serves two purposes, it deflects hot oil away from the intake but it also retains the lifters in their bore should a pushrod get damaged IE bent....
 
cudamark said:
The 318-3 engines have a water crossover too.....and a cast iron timing cover.
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And a steel crank for sure, and sodium filled valves, and valve rotators! (just guessing but I wouldn't doubt it)
 
It's been years (decades?) since I've dealt with a 318-3 in it's natural state, but I thought the coolant for the manifold came from the rear coolant ports of the heads; and the exhaust crossovers just weren't used in that application- but they were still present in the heads? I'm never wrong, but I've been mistaken a few times... :) I'm sure somebody will refresh my memory if needed!
 
The ones I ran across were in motorhomes. There was a fitting on top of the water pump housing and on the intake where the crossover passageway is located. There was a metal coolant line connecting the two. The heads are different than the 318-1 engines. They have a water crossover and 18mm tapered seat spark plugs....like what comes on a Ford.
 
This is how it looks right here. Those remaining open crossover ports let the heat out.

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67Dart273 said:
Magic number for "what" exactly? Water does not boil at 212 in a pressurized automotive cooling system
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Intake plenum floor. Vaporizes some of the fuel mixture. Looking for 15-20% vapor to ignite the test of the atomized fuel once in the cylinder.
 
Also…
Fahrenheit 212 is a bad german metal band from the 90’s. Check out Der Hexer. To further dipsplay my irrelevance. I have it on cassette.
 
That hole there is where you store miscellaneous screw, clips, linkage parts etc. I usually keep my only accelerator pump clips in there.
 
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