Jump to content

Hood Scoops....Pros and Cons


Guest
 Share

Recommended Posts

Hi Guys,<BR>Been looking around <A HREF="http://www.cars-on-line.com" TARGET=_blank>http://www.cars-on-line.com</A> and was thinking, Hood Scoops look kick ass. I was wondering what are the pros and cons for them? I know for one I'd need two of em (I'm not getting rid of the beautiful chrome stip down my hoods center). Can you just buy em, paint em, and approximate a hole for them? Or would I need to make some kind of piping so the air led directly into the carb? What are the pros and cons into doing something like this? I know from turbo threads elsewhere that you would actually be making roughly .67 psi of boost at 80~90, and that's a pretty common speed for on the highways around here (course, not at this time of year). But what about Drag...or don't they actually produce drag since the air is sucked right through the engine....Oh My, my head's starting to hurt now...

Link to comment
Share on other sites

As I understand it, the main benefit of a hood scoop is to feed colder (more dense) outside air to the carb rather than the hot air under the hood. This would thereby get more oxygen into the combustion chambers and provide for better conversion of fuel energy. That's apparantly why cowl induction works just as well, if not better. There the cold air is drawn in from the high pressure area at the base of the windshield.<P>Of course, this point is for cars with the scoop directing air to the carb with foam rubber ducting (i.e. 1970 GS). A purely decorative scoop that simply directs air into the engine compartment (i.e. 1955 Thunderbird) is probably of little help in performance.<P>However, your aerodynamics observation brings up an interesting point. I've seen several sources seriously question the merit of the 1970 era Buick GS hood scoops, not becuase of any wind resistance (which is probably very minor an any street speeds) but because their design as more of an open hole than a forward facing scoop actually creates a vaccuum at speed directly at the intake point. If you imagine blowing accross the top of an open bottle, or the way a garden sprayer attached to a garden how works, and look at the design of the GS scoops, this argument seems to make sense.<P>Has anyone come accross any serious study of this? Has anyone actully measured pressures at this point with any accuracy? Has anyone, perhaps, attached forward facing "ram" scoops onto their GS and measured an improvement? <BR>And if you did, was it worth making the car that ugly? rolleyes.gifwink.gif

Link to comment
Share on other sites

Take a look at the '68 Camaro cowl induction. It used an air cleaner housing that had a large vary large rubber connector to a metal ducting that was mounted to the firewall. It got air from the cowl vent area where the windshield wiper linkage is. This proved to work well as it gets air from the turbulent area at the base of the windshield.<P>I made a ram air system ala Olds 442 for my '65 Gran Sport. It was very well done (if I may say so myself) with two four inch hoses going down through holes in the inner fenders right behind the rad support to scoops under the bumper. <BR>It look awsome!and really caught a lot of attention, but I couldn't say that it made a difference at the track, the times and MPH stayed the same. <BR>I think the Camaro style would be the only way I would go, if I insisted on doing it being I found mine didn't appear to work. <P>------------------<BR>buickfam@aol.com<BR>Life long Buick Fan.<BR>1965 Skylark H/T<BR>1965 Gran Sport Convertible<BR>1948 Chevy Pickup with 401 Buick.<BR>"Fan of anything that moves human beings"

Link to comment
Share on other sites

Just a thought on a good topic. What about using the lower two sections of the grill for air induction? I don't know about others, but the 70-72 Skylarks have that large one piece grill, with one large upper grill and two smaller grill sections near the parking lights. What about piping air from there into the breather? Using a dual snorkle breather of course. :-)<P>Just another thought.<P>-Scott<BR>

Link to comment
Share on other sites

As I was taught years ago in drag race school: The most pressure is at the base of the windshield for a street type car.On a 74 bb Camaro race car ,I used an old time pro stock type of hood scoop. It stood about 7 inches off of the hood and faced forward. It was sealed to the carb by means of a velocity stack with foam seal and would actually swell from the air coming into it at the top end. this car ran 10.90 at 125 at 5500 ft in Denver. Scoops do well but I think for a street car they are decoration or used to suck in colder air than under the hood. another thought is: on a hot summer day the guy that has his dual pick up scoops under the bumper is using air that is probably hotter than under the hood. Ken<P>------------------<BR>455 Ken

Link to comment
Share on other sites

Cowl induction is nice, but not in this application. The main reason being I don't want to lost the chrome stripe down the hood. That's why I was thinking of two forward facing hood scoops (one on either side of the hood) mounted to two hoses of some sort into a dual intake air cleaner box thingy.

Link to comment
Share on other sites

67, sounds like the Comet FX cars. They had a cool square inlet on the leading edge of the hood on each side. And the cowl induction I am refering to didn't use the hood scoop! I said that the air cleaner had a rubber piece that hooded up to the FIRE WALL duct that got air from UNDER the cowl panel where the wiper linkage is. There was a "cowl induction hood" used on Camaros, this is not what I am talking about. If you do a search on the net for "cowl induction"+68 you may come up with photos. smile.gif<P>455Ken, I had forgotten, I was told that is why my under bumper scoops didn't work! frown.gif They sure looked good though!<P>------------------<BR>buickfam@aol.com<BR>Life long Buick Fan.<BR>1965 Skylark H/T<BR>1965 Gran Sport Convertible<BR>1948 Chevy Pickup with 401 Buick.<BR>"Fan of anything that moves human beings"

Link to comment
Share on other sites

I just talked to my Chevy nut friend, they were first used in 1962 or 63 427 "mystery motor". And were also avaiable over the counter for '66-'67 Chevelle SS396. <P>Something similar is available from a guy in Canada "Air inlet Systems" 1-905-549-6135 <BR>email>> ramairbx@wchat.on.ca<P>------------------<BR>buickfam@aol.com<BR>Life long Buick Fan.<BR>1965 Skylark H/T<BR>1965 Gran Sport Convertible<BR>1948 Chevy Pickup with 401 Buick.<BR>"Fan of anything that moves human beings"

Link to comment
Share on other sites

They are called a "Cowl Plenum" air cleaner.<P>------------------<BR>buickfam@aol.com<BR>Life long Buick Fan.<BR>1965 Skylark H/T<BR>1965 Gran Sport Convertible<BR>1948 Chevy Pickup with 401 Buick.<BR>"Fan of anything that moves human beings"

Link to comment
Share on other sites

Here's what it looks like, cool stuff that works! <A HREF="http://www.camaro-untoldsecrets.com/images/gif/crossr4.gif" TARGET=_blank>http://www.camaro-untoldsecrets.com/images/gif/crossr4.gif</A> <P><P>------------------<BR>buickfam@aol.com<BR>Life long Buick Fan.<BR>1965 Skylark H/T<BR>1965 Gran Sport Convertible<BR>1948 Chevy Pickup with 401 Buick.<BR>"Fan of anything that moves human beings"

Link to comment
Share on other sites

Ok, I was thinking you meant the raised hood cowl intake. That style in the pic may work, and probably wouldn't be too hard to do..although I'm envisioning a little metal sawing. What about the front facing hood scoops though? I'm thinking about this from a decorative standpoint mostly to be honest.

Link to comment
Share on other sites

Hey MARTINSR did you fatten up your carb when you added your ram air. My experience has been you need more fuel since you are adding cooler dense air.A set like yours or others can be worth a tenth or more in the quarter.

Link to comment
Share on other sites

I used a system similar to the thunderbolt on my 70 GS I took both inside lights out and fabricated a dryer hose from both of these into the base of my GS air cleaner.<BR>I then put 2 of the stone gaurds in front of the opening . Looked sweet and picked up about 1/10th in the 1/4.<P>------------------<BR>Wildcats.Cars of comfort and speed.<BR>Looking for 70 nos wildcat parts.<BR>Russ

Link to comment
Share on other sites

Stage2Pat,I ran a 1000 CFM Thermoquad. But as I stated I didn't see a difference. I was at Sea level and with the scoops three inches off the hot pavment, it's no wonder it didn't work. The cowl plenum that I have posted here that Chevy used is the way to go.<P>'67, for looks..it doesn't matter then, do as you wish. I think it would work pretty good also though. <P>------------------<BR>buickfam@aol.com<BR>Life long Buick Fan.<BR>1965 Skylark H/T<BR>1965 Gran Sport Convertible<BR>1948 Chevy Pickup with 401 Buick.<BR>"Fan of anything that moves human beings"

Link to comment
Share on other sites

Here is a better, color photo....scroll down to it.... <A HREF="http://www.camarogenerations.com/brett68.html" TARGET=_blank>http://www.camarogenerations.com/brett68.html</A> <BR><P>------------------<BR>buickfam@aol.com<BR>Life long Buick Fan.<BR>1965 Skylark H/T<BR>1965 Gran Sport Convertible<BR>1948 Chevy Pickup with 401 Buick.<BR>"Fan of anything that moves human beings"

Link to comment
Share on other sites

  • 3 weeks later...

water injection is really only useful as a cheap way to stop detonation. i will paraphrase from a book i am reading on turbos:<P>water injection is crap you dont need if the system is designed right from the start. it does not add power, and the water does not burn.<P>allan<P>------------------<BR>allan<BR>--------------<BR>50 special, 455/th400<BR>64 stude gt hawk, 289/auto<BR>76 poncho GP, 400/th400

Link to comment
Share on other sites

Allan, I think Pat was asking abour water <B> injestion. </B> In other words, how do the various systems (and/or the "cowl plenum" device) avoid sucking in raindrops while in operation. Although I've seen nuemerous drain holes in the air cleaners of many systems, if there's a standardised theory for keeping water out of the air filter I'm not aware of one. <P>Anyone? confused.gif

Link to comment
Share on other sites

You are correct Dave. While I'm not talking about taking my car for a swim, couldn't getting caught in a big rainstorm be a bit of a problem?

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...