I think it is well known that the engine compartment intake (grills right behind rear glass) is in a low pressure area which is less than ideal. The stingers have a hood vent that is positioned farther back on the engine lid, but was there any real science that went into the positioning of these vents?

I'm currently designing a RAM air intake for my 3x Webers, and it means sacrificing a lid in the process. I could do some testing myself to try and determine the ideal placement of the intake scoops, but wanted to see if someone already went through the trouble. The flow of air changes based on speed, but in general what would be an ideal placement for speeds 30mph+. I would be using the RAM intake to feed the Webers exclusively while the stock grills would only be for engine cooling.

TLDR: Where should I place my RAM intake scoops on the rear decklid to capture the most air?

Joseph Pellerin IV
O.C. Vintage Corsa

---

1965 Corsa 140 Coupe Evening Orchid w/ Ivory & Black interior + Split Bumper

On the old McIntosh V8 racer we had the oil cooler mounted in the rear deck lid area with a Naca duct in the lid, it helped tremendously with the oil temp so I’ve concluded the further back the higher the pressure

1964 Bill Thomas Monza Replica Racer
1964 Spyder Street Car
1998 Honda Prelude Dirt track car
1967 Crown V8 under construction
Mike Levine
Cumming Georgia
North of Atlanta

Works but not the look I'm going for. I'm trying to find where the air flows across the deck lid. It would be easy to capture air above the roof line.

Phil Dally Wrote:
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> Already been done.

Right, I wonder how much further forward the scoop or NACA could be while still maximizing the amount of air captured.

I'm going to have a low but wide profile ram that compresses the air before returning it to high pressure inside a box that the weber's velocity stack and air cleaner will sit in. With the profile ram air I'm going for, it would start to take effect at 20mph but the issue is finding out where to position it for ideal air flow.

v8vair Wrote:
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> On the old McIntosh V8 racer we had the oil cooler mounted in the rear deck lid area with a Naca duct in the lid, it helped tremendously with the oil temp so I’ve concluded the further back the higher the pressure

The EM's and the LM's have entirely different shapes to their Greenhouse, so the flow characteristics are definitely different.
63turbo (A.K.A. Kevin Nash is our resident Air-Flow Engineer) and I have had many conversations about this topic.
On the LM cars, the point of maximum Deck-lid airflow is right at the very back of the lid.
Like around the LAST FOUR INCHES or so.
The most flow is going to be on the outer side, as more air actually comes around the Greenhouse, than over it.
Do you drive your Corvair in the Rain?
If so, pay close attention to your interior Rear-View Mirror!
The water flow pattern over the rear window, is DIRECTLY affected by the Airflow, and is quite eye opening.
For the best Ram Effect (maybe not visual appealing), would be to mount your Ram Scoops ON the rear Fenders.

-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
WA. state, 1 mile south of the Canadian border, I am not at the end of the world, but you can see it from here.

JPPIV Wrote:
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> I think it is well known that the engine compartment intake (grills right behind rear glass) is in a low pressure area which is less than ideal. The stingers have a hood vent that is positioned farther back on the engine lid, but was there any real science that went into the positioning of these vents?
>
> I'm currently designing a RAM air intake for my 3x Webers, and it means sacrificing a lid in the process. I could do some testing myself to try and determine the ideal placement of the intake scoops, but wanted to see if someone already went through the trouble. The flow of air changes based on speed, but in general what would be an ideal placement for speeds 30mph+. I would be using the RAM intake to feed the Webers exclusively while the stock grills would only be for engine cooling.
>
> TLDR: Where should I place my RAM intake scoops on the rear decklid to capture the most air?

Heres a post I did on that very subject, using a manometer, and testing numerous spots. [corvaircenter.com]

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car
Test Start#2 [www.youtube.com]

Many years ago Ned Madsem publoshed infor mation on this very topic. To keep this short. He said the high pressire area created by an air dam was an inch and 1/2 wide for each inch of height.. this is reference to the stinger ducts. I have no info on naca ducts.. thos is from an old guy's memorey

Tom Miller
Circle City Corvairs
Corsa

Thankfully this is my daily driver

Phil Dally Wrote:
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> If you're ever going to race your car in any sanctioned event you should check the air (hood) scoop rules. They are very specific and picky in SCTA-BNI Landspeed. Frankly I was vairy surprised Greg Lloyd was able to get that scoop pictured above through impound.

Wow lots of great info there, too bad there wasn't a render of airflow over a stock LM coupe body. The renders that are there give me a pretty good idea, and I will end up putting the RAM intake on the last 1/3 of the deck lid. Question is, how high should the scoop be to ensure that I'm catching the air?

63turbo Wrote:
-------------------------------------------------------
> JPPIV Wrote:
> -------------------------------------------------------
> > I think it is well known that the engine compartment intake (grills right behind rear glass) is in a low pressure area which is less than ideal. The stingers have a hood vent that is positioned farther back on the engine lid, but was there any real science that went into the positioning of these vents?
> >
> > I'm currently designing a RAM air intake for my 3x Webers, and it means sacrificing a lid in the process. I could do some testing myself to try and determine the ideal placement of the intake scoops, but wanted to see if someone already went through the trouble. The flow of air changes based on speed, but in general what would be an ideal placement for speeds 30mph+. I would be using the RAM intake to feed the Webers exclusively while the stock grills would only be for engine cooling.
> >
> > TLDR: Where should I place my RAM intake scoops on the rear decklid to capture the most air?
>
> Heres a post I did on that very subject, using a manometer, and testing numerous spots. [corvaircenter.com]

Interesting, this is is a very crude sketch of the current Ram intake. This is just the intake scoop, and the aerodynamics are extremely simplified here. Still working on it...


cooterr Wrote:
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> Many years ago Ned Madsem publoshed infor mation on this very topic. To keep this short. He said the high pressire area created by an air dam was an inch and 1/2 wide for each inch of height.. this is reference to the stinger ducts. I have no info on naca ducts.. thos is from an old guy's memorey

Where you have your preliminary scoops at is really good. For sizing, you shouldnt need to make them any higher than 2", this was the approximate height of my probe for most of the tests done on the body. The minimum area for each scoop need to at least be the same as the total area of your airhorns on each side. Given that the LM air intake is in such a bad spot, you would do really well for your scoops to be sized well enough to handle pressurizing the fan intake as well as the air demand for the engine. In which case, the total minimum intake area should be around 36-40 square inches, and more is better.

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car
Test Start#2 [www.youtube.com]

This is a pretty interesting topic. Just goes to show ya that we do have some hidden engineers amongst us.( well, at least here in Orange County, Ca. LOL )

Doug Ward
Orange, Calif.
65 Corsa 180, 64 Monza convertible, 61 Lakewood, 61 Monza

Have you given any thought to grafting intake vents into the 1/4 panels ahead of the wheel openings?

It might be possible to use the 1970-1981 Pontiac Trans Am front fender air extractor vents in such a way that they would intake air?

1962 95 F.C. Van
1964 Greenbrier Deluxe
1965 Monza Coupe
1965 Monza Convertible
Westminster, Maryland

MID ENG enthusiast &
prior Kelmark owner.

Clarks has these: [ssl.corvair.com]

They are too long to work well but would appear to be easy to shorten to close
to the right length

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car
Test Start#2 [www.youtube.com]

I have given it a lot of thought and considered putting NACA ducts right above the wheel well. It would get great airflow but, I would have to cut into a not so easily replaceable body panel. A lid can easily be switched out if I get tired of the look.

Caraholic4life Wrote:
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> Have you given any thought to grafting intake vents into the 1/4 panels ahead of the wheel openings?
>
> It might be possible to use the 1970-1981 Pontiac Trans Am front fender air extractor vents in such a way that they would intake air?

Those look pretty good, might consider them. Thanks!

63turbo Wrote:
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> Clarks has these: [ssl.corvair.com]
>
> They are too long to work well but would appear to be easy to shorten to close
> to the right length