# offenhauser intake



## modelt4 (6 mo ago)

hi all, i am after some info re intake. in the center under where carb fits there is a chamber. that i think has exhaust gas flow through. there is a hole that goes right through, i am puzzled, if the two center small ports has exhaust gas goin through its a leak ,is it not maybe gas does not go through it. and is just a hot air passage hole is just so it breathes also the valley pan has a breather hole in it that intake is so close to nothing woujd fit i have sealed it off


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## armyadarkness (Dec 7, 2020)

Your post is a bit unclear, but Im going to give my best guess answer.

It's a heat crossover, to warm the engine up quicker. Pontiacs came that way from the factory, because they dont like being cold. 

This is assuming that your intake has that crossover and is not some other failure.

My Edelbroack has it... although I block mine.


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## O52 (Jan 27, 2019)

The valley pan hole is for the PCV (Positive Crankcase Ventilation) valve. It's a valve that pulls the fumes from the crankcase back through the intake manifold to be reburned. Depending on your year, it will be behind the carburetor (prior to 67) or in front of the carb (68-79). Again, depending your year of engine, there will be a steel tube from one of the valve covers to the air cleaner, or a simple breather. 
Since you posted under the 2004-2006 GTO forum, its all a guess as to what engine you have


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## armyadarkness (Dec 7, 2020)

Yeah, and BTW, dont block off that breather hole in the valley pan!!!!

Put this in:









Then this:









And then run a hose up to the port on your carb.


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## armyadarkness (Dec 7, 2020)

Your valve covers should each have a breather in them.


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## lust4speed (Jul 5, 2019)

Probably talking about a later EGR manifold.


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## modelt4 (6 mo ago)

thanks for replys it is a 71 engine yes its a heat crossover


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## modelt4 (6 mo ago)

i am still puzzled why there is a hole in the manifold where it goes under carb that is going to blow from exhaust gasses they all seem to have it should i seal them up thing is once i i have sealed the manifold down its a new intake set to rectify it


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## armyadarkness (Dec 7, 2020)

The exhaust gasses that you reference, heat the intake up faster, so that the engine performs better, much faster.

Otherwise, when it's 40 degrees out, it'll take a good ten minutes before the car can be easily driven... 

That beind said, one of the MOST COMMON Pontiac mods is to seal the passage. Many companies make gaskets to do it.

Most old-skool guys here, recommend leaving them open... but if your car runs hot or you have heat issues with the carb, then it's a great way to resolve it


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## modelt4 (6 mo ago)

there is a hole that looks like it will leak gasses i need to look at it again this mornin to see if hols is a tube that gasses cant get into only thing that makes sense thank you for reply


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## O52 (Jan 27, 2019)

Pictures would be great!


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## armyadarkness (Dec 7, 2020)

O52 said:


> Pictures would be great!


Im kind of afraid to see what the Hell we're talking about.


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## modelt4 (6 mo ago)

O52 said:


> Pictures would be great!


hi thanks for replys i have got to the bottom of it there is a tube that goes through exhaust warmng chamber looks like a hole into it top and bottom


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## modelt4 (6 mo ago)

modelt4 said:


> hi thanks for replys i have got to the bottom of it there is a tube that goes through exhaust warmng chamber looks like a hole into it top and bottom


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## armyadarkness (Dec 7, 2020)

modelt4 said:


> hi thanks for replys i have got to the bottom of it there is a tube that goes through exhaust warmng chamber looks like a hole into it top and bottom


thats for the choke


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