Vents on front slope of GT

[Dennis Texas]

I don't see any mention of a use for them, my car runs cool and I live in Texas so don't really guess that air flow from the two vents on radiator is a important consideration, would there be any useful effects to tie my air cleaner into that sort of like ram air scoop to help force air into the intake system. It's a stock flat top piston 1.9

[namba209]

You may not believe it, but once you get to about 40 MPH, the area in front of the radiator is pressurized. Found that out in Willit?, with the hood not locked down, the air pressure in the engine compartment coming through the radiator, raised the hood. The faster you go, supposedly, the air pressure goes up. Case in point, the guys building a Bonneville GT want to close off the front opening to about 4 square inches. That's all they'll need for cooling purposes and carb air inlet.

[guyopel]

I do not have the front vents on my car and have had no cooling problems ( Atlanta area ) .
John

[GTJIM]

Those two vents are specifically for letting hot air out, especially when the GT is stopped or parked, to reduce the boiling of the fuel in the carb bowl and lower under-hood 'cooking' temperatures. Put your hand above one when you stop.

As for using them for a cold air intake - they are designed to extract air at speed - so lower pressure instead of increasing it near them.

You need an intake back nearer the front screen high-pressure area or a 'corvette' type rear facing inlet. Maybe a NASCAR (NASA?) inlet would be even better - the ones level with the hood that start out small & shallow then get wide and deep towards the rear in a compound curve.

[Dennis Texas]

Originally Posted by GTJIM Those two vents are specifically for letting hot air out, especially when the GT is stopped or parked, to reduce the boiling of the fuel in the carb bowl and lower under-hood 'cooking' temperatures. Put your hand above one when you stop. As for using them for a cold air intake - they are designed to extract air at speed - so lower pressure instead of increasing it near them. You need an intake back nearer the front screen high-pressure area or a 'corvette' type rear facing inlet. Maybe a NASCAR (NASA?) inlet would be even better - the ones level with the hood that start out small & shallow then get wide and deep towards the rear in a compound curve.

I was referring to the two openings on the front slope between headlights by the opel emblem, in front of the hood opening towards front bumper, but thank you for taking the time to give a informational response.

[GTJIM]

Thanks for the clarification:

Once again - designed by Stuttgart University, in their wind tunnel to bleed high pressure air down from the front of the car to help cool the top of the radiator and 'ram' air into the area the stock intake draws from.

The danger of directly hooking up a cold air intake system here is sucking in a goodly amount of water when it rains - or splashes up when going through puddles. The area in front of the radiator also acts as a water separator for the stock intake.

The area around the stock snorkel entrance is designed to be one of the highest pressure areas under the hood - then the tapered shape of the snorkel is designed to slow the air as it travels into the stock air cleaner - to further build pressure - neat huh!

[scrapman]

Interesting information to know. My question is how does good air make it all the way back to a Weber carb that does not have the snorkel or the original air solex intake. Seems like getting cold air all the way back from the front of the car past the radiator is not very likely. My air cleaner is the rectangular air filter send along with replacement Weber carb. Anyone's insights on this would be very much appreciated.

Rick

[GTJIM]

Originally Posted by scrapman My question is how does good air make it all the way back to a Webber carb that does not have the snorkel or the original air solex intake. Rick

That is 'it' in a nutshell - the square air cleaner on top of the carb condemns the carb to getting the hot air that has passed through the radiator.

That is why all the fuss about snorkels and tubes!

See Here: http://www.opelgt.com/forums/afterma...r-adapter.html

[scrapman]

As I suspected. The rectangular air filter from K&N is what came with my Webber when I ordered it. What are others with Webbers using for an air filter? Is there a snorkel I should be using or is there another air filter assembly that fits on top of the Webber that includes a way of getting good clean air to the carb?

Rick

[scrapman]

Sorry dumb question - read the link! I was skimming the post and was in a hurry.

Rick

[MICAH1]

Rick,
You can either acquire the original snorkel and build on that, or create your own cold air intake. Your choice, check the search feature.

[tekenaar]

Post #28 of GTJIM's link (mine) details using stock parts with a snorkel adapter for the Weber . . .



. . . and results in this, currently installed on Ted's GT (San Antonio) . . .

[MICAH1]

Hey Otto,
This thread started questioning the use of the two vents between the headlights.... what happen???