Hood venting
Thread Starter
Melting Slicks
Joined: Oct 2006
Posts: 2,938
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From: hebron IL
C3 of Year Finalist (appearance mods) 2019
Hood venting
So I found this pic on facebook. The owner had recently bought this car and wasn't sure if the hood is stock height with front venting cutout. Does it look stock height. I kinda like the vent cutouts in the front. The car is a '75 greenwood sports wagon conversion.
Le Mans Master
Joined: Oct 2010
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From: melbourne florida
2023 C3 of the Year Finalist - Modified
That's the stock hood. I have a friend that did the back end close to the windshield, but his didn't have the factory vents to start with.and he did it far enough forward of the windshield that it vented before the firewall.
Race Director
Joined: Mar 2017
Posts: 11,899
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From: Virginia
That looks like the stock hood. I don't think those vents do anything useful, though. You'd want them a bit further back to extract hot air from past the radiator, like on a C7.
What does the underside of the hood look like?
What does the underside of the hood look like?
Thread Starter
Melting Slicks
Joined: Oct 2006
Posts: 2,938
Likes: 173
From: hebron IL
C3 of Year Finalist (appearance mods) 2019
Do you think it would help flow air out the back vent?
Racer
Joined: Jun 2012
Posts: 269
Likes: 52
From: Springfield, TN
The grill at the rear of the hood is actually an inlet to an airbox above the air cleaner. Essentially a cowl induction setup.
It draws air from the high pressure area at the base of the windshield and routes it into the air cleaner.
You can't vent air out the back of the hood because of the high pressure there. Also, you don't want vents ahead of the radiator, because it decreases the radiator efficiency.
If you want to vent the engine compartment through the hood, you need to do it in the area behind the radiator back to about where the rear of the carb/air cleaner is.
Another option might be to increase airflow out the side vents.
It draws air from the high pressure area at the base of the windshield and routes it into the air cleaner.
You can't vent air out the back of the hood because of the high pressure there. Also, you don't want vents ahead of the radiator, because it decreases the radiator efficiency.
If you want to vent the engine compartment through the hood, you need to do it in the area behind the radiator back to about where the rear of the carb/air cleaner is.
Another option might be to increase airflow out the side vents.
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Just another Corvette guy
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From: Palm Springs, CA.
I like it.
These conversions were cool back in the 70's. Then they were gay for a while. Now they're old enough to be nostalgic again. I'd buy one if the price was right.
I agree with the others here, I think the vents up front would defeat the purpose of the radiator seals for good cooling effect.
Greg
These conversions were cool back in the 70's. Then they were gay for a while. Now they're old enough to be nostalgic again. I'd buy one if the price was right.
I agree with the others here, I think the vents up front would defeat the purpose of the radiator seals for good cooling effect.
Greg
Race Director
Joined: Mar 2017
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From: Virginia
The grill at the rear of the hood is actually an inlet to an airbox above the air cleaner. Essentially a cowl induction setup.
It draws air from the high pressure area at the base of the windshield and routes it into the air cleaner.
You can't vent air out the back of the hood because of the high pressure there. Also, you don't want vents ahead of the radiator, because it decreases the radiator efficiency.
If you want to vent the engine compartment through the hood, you need to do it in the area behind the radiator back to about where the rear of the carb/air cleaner is.
Another option might be to increase airflow out the side vents.
It draws air from the high pressure area at the base of the windshield and routes it into the air cleaner.
You can't vent air out the back of the hood because of the high pressure there. Also, you don't want vents ahead of the radiator, because it decreases the radiator efficiency.
If you want to vent the engine compartment through the hood, you need to do it in the area behind the radiator back to about where the rear of the carb/air cleaner is.
Another option might be to increase airflow out the side vents.
That about covers it!I'd add that later in production, there is no longer an inlet at the rear of the hood. On my black 79 (same hood, without the cutouts), there is a rubber seal at the rear. If it is absent, it will reduce cooling efficiency, as air will be forced in ahead of the windshield, and act to block air that would otherwise flow through the radiator.
Unless the vents at the front of the hood (or the rear of the hood) lead ONLY to the air cleaner, you will at best do nothing beneficial, and at worst defeat your radiator's cooling efficiency. I should caveat that by saying there are several on this Forum that do exactly that, reduce the available inlet air to the radiator, because they race their cars, and minimizing flow under the car at speed is important for handling, and at speed they get enough flow over the radiator to cool the car.
But if it looks cool, don't worry about it too much. The C7 extractor (behind the radiator), both looks cool AND is functional.
Race Director
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From: Danville Illinois
2025 Corvette of the Year Finalist - Modified
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2019 C3 of Year Finalist (appearance mods)
I like it, old school look.
Appears to be a stock hood tho.
Appears to be a stock hood tho.
Instructor
Joined: Jul 2011
Posts: 246
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From: Pell City AL
You can't vent air out the back of the hood because of the high pressure there
Always learning something new in this forum!
Drifting
Joined: Jun 2012
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From: Port St. Lucie Fl
Safety Car
Joined: Dec 2007
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From: Beautiful East Texas
I like the way the 4 vents look in the photo above, but seems to be too close to the radiator to be effective...
There is an aftermarket vent kit similar to the C7 style that's designed for a C3 hood... it looks pretty decent
but I can't remember the name off hand.
mardyn
There is an aftermarket vent kit similar to the C7 style that's designed for a C3 hood... it looks pretty decent
but I can't remember the name off hand.
mardyn
Team Owner
Joined: Oct 2004
Posts: 81,241
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From: altered state
St. Jude Donor '05
venting when you are sitting still imo more important, I say let that hot air rise and get it out any way you can.
Seen a few use ZL1 pieces which function..its more work but then they are molded in they look so much better than being riveted, glued on etc.
Like those wagons, pretty unique. He wont see another one on the road like his thats for sure.
Seen a few use ZL1 pieces which function..its more work but then they are molded in they look so much better than being riveted, glued on etc.
Like those wagons, pretty unique. He wont see another one on the road like his thats for sure.
Le Mans Master
Joined: May 2003
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From: Fernandina Beach FL
2023 Restomod of the Year finalist
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Here's a few-
Fellow forum member "Denpo" hand made these-
Here's what I thought would be a "cool" idea- especially with a low profile LS engine- L88 hood with a fan- artist rendition
