Hood scoop design

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Ira
Posts: 98
Joined: Wed Jan 27, 2010 7:20 pm

Hood scoop design

Post by Ira »

Okay I'm on my break right now so I'll be brief.

I was thinking of building a set of hood scoop/damper assemblies for my coupe.

Thought was... a set of nostalgic styled scoops with dampers that open at WOT and route air to the carbs. In my mind I see a set of well finished air cleaners (one on each side) nestled down in a duct. The top of the duct would have some weather stripping around the opening... providing a positive seal to the hood and scoop. Very similar to the old Ram Air intakes back in the day.

The other thing I thought of, was having a "manifold" between the two ducts (or air cleaner shrouds) which would allow excess air to flow directly over the engine.

Key to this all would be to have the carbs, cams and ignition set to utilize the additional air.

Anyhow what are people's thoughts? Feel free to use the little machine gun smilie :assault: when blasting my idea ::-):

Ira :chevy:
bjbuchanan
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Joined: Thu Feb 04, 2010 10:02 am

Re: Hood scoop design

Post by bjbuchanan »

I like the idea, maybe something that is sync'd with the throttle to sense wot so that the trunk is smooth until you punch it and then you get a nice ram effect. Idk i would think some silicone wiresm, a pertronix II and some reworked carbs, nothing too heavy. You probably wouldn't have to bother with any ducting for cooling just leave the grille behind the rear window alone and all will be well
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Scott H
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Location: Hesperia, CA

Re: Hood scoop design

Post by Scott H »

like the Yenko Stinger scoops?
Scott
1960 Monza Coupe
1965 Evening Orchid Corsa Turbo (project)
1961 Rampside (project)
1964 Spyder coupe (patina car, running)
1964 faux Spyder (project/parts car)
1964 Monza (parts car)
1963 Monza (parts car)
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Ira
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Joined: Wed Jan 27, 2010 7:20 pm

Re: Hood scoop design

Post by Ira »

Scott Howey wrote:like the Yenko Stinger scoops?
Nah... I was thinking of something different.

Here's the way I see it:

1. My car will be kind of a poser car... I want it to look similar to a vintage race car (wthout all of the logos and numbers)but with the ability to go across the country. So most likely the only race track it will ever see is an autocross course.

2. High speeds (above 100mph) for prolonged periods can get dicey (according to my father in law and some posts I've seen). This car won't really be designed to travel at higher speeds... I.E. greater than sane highway speeds... 85 or so.

3. The gearing in this car will be lower allowing me to get the most "wow" factor on short courses and off of the line. I was toying with the idea of running 3.89s like the Yenko coupes.

So factoring all of that into it; aerodynamics isn't much of an issue to me. Looking correct... playing the part... that's what I'm after. Now having said all of that...

To answer your question; what I was thinking of was similar to some of the old 50s and 60s race cars.... basically it was about a 2 or 3 inch tall vent (kind of looked like a cup sliced in half) and elegantly "plopped" onto the fender. I want to say some Jags in the 50s incorporated this "wicked bad" technology.

Anyhow I'm going to throw this design onto some graph paper (old school drafting technique for those of us who don't do CAD) and then let the mechanical engineer at my plant tear it to shreds... ::-):
bjbuchanan wrote:I like the idea, maybe something that is sync'd with the throttle to sense wot so that the trunk is smooth until you punch it and then you get a nice ram effect. Idk i would think some silicone wiresm, a pertronix II and some reworked carbs, nothing too heavy. You probably wouldn't have to bother with any ducting for cooling just leave the grille behind the rear window alone and all will be well
As to the engine... I was thinking along the same lines. In essence all I want to do is get the most out of my factory 140. For right now we've decided against new cams.

Ira :chevy:
bjbuchanan
Posts: 27
Joined: Thu Feb 04, 2010 10:02 am

Re: Hood scoop design

Post by bjbuchanan »

Maybe try some c scoops on the quarters and recess the area slightly so its not a huge aerodynamic penalty amost like a naca duct like on 71-71 mustang hoods. then run ram air from them?
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Scott H
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Re: Hood scoop design

Post by Scott H »

Similar to Dmorsk's car?
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Scott
1960 Monza Coupe
1965 Evening Orchid Corsa Turbo (project)
1961 Rampside (project)
1964 Spyder coupe (patina car, running)
1964 faux Spyder (project/parts car)
1964 Monza (parts car)
1963 Monza (parts car)
User avatar
Ira
Posts: 98
Joined: Wed Jan 27, 2010 7:20 pm

Re: Hood scoop design

Post by Ira »

Pretty close to that example Scott... but it will be more rounded. Very similar to the 69 GTO Judge's hood tach.... except turned around to face the air flow.

I will be mounting these on the hood. A hood is easy to replace, whereas modifications to the body are more difficult to erase. One day down the road someone might want to restore this car back to it's original form... I doubt it, but who knows who will end up purchasing this car... Maybe one of you guys ::-):

In addition I will be using a system to manually open and close the dampers... It'll be easier, cleaner and lighter.

IRa :chevy:
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Ira
Posts: 98
Joined: Wed Jan 27, 2010 7:20 pm

Re: Hood scoop design

Post by Ira »

Okay so a few days ago I ran my air box design past our plant engineer.

Bill is a great guy and took time out of his schedule to go over the specifics with me. His qualifications are mechanical engineering, HVAC systems (here in the pharmaceutical field), metal working/fabrication and avation... a huge spread there but the guy is very heavy into the physics... specifically when it comes to airflow.

Anyhow he stated that if a horsepower increase was the main goal... the only way to obtain it is to have a seal from the scoop directly to the carb... IE no leaks or you decrease your charge. He figured the easiest way to get to where I wanted to go would be velocity stacks, with a duct leading to a hood scoop.

Velocity stacks... :think: ... very retro and it would give the car a vintage appearance. I had been thinking of that anyway but after finding out how much a set of air cleaners was $220... I'm sold. :assault: Airbox.... terminated.

Now obviously I will have to tinker with the jetting a bit to keep it from running lean but realistically it's not a turbo or super charger... therefore one jet size should be enough... I would think.

In my opinion the next step will be to grab some yarn and do some aerodynamics tests to determine where the "dead" zones are across my hood. If in fact the air movement is minimal across the hood then I go back to the drawing board.

So this is what I'm thinking as of this moment. As with any project all aspects are subject to change and negotiable ::-):

Ira :chevy:
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