Hood Scoop Query

[Rob Campbell]

G'Day from Australia fellow Mopar enthusiasts, my name is Rob Campbell.

I own a 1969 Ford Capri, however powering this beast is a 440.

I am due to race at the largest drag racing event on the Australian calender in 2 weeks, recently the car has run 3 tenths slower.

We feel we have sorted out some of the causes, however we hope to gain some extra horspower by sealing the hood scoop to the carby.

I have read that Mopar issue a techinical bulletin number 14 whcih deals with this issue.

Can anyone advise me of where Ican get a copy of the bulletin or advise me of the best method to mount a scoop to the carby?

Cheers,

Rob Campbell

[cuda367]

The bulletin you referred to is for the 2-4 tunnel ram pro stock type hood scoop. The main point of the installation was to keep the top of the carb 1/2 inch below the floor of the scoop. If this is a single carb setup and the hood is above the top of the carb, use a good air cleaner base(like the one from the magnum engines) and get it sealed to the hood. The second option is to use a velocity stack like Barry Grant sells(not one of the tall small diameter ones). Do not use a piece of pipe to go from carb to hood. The idea I am trying to get across is to use a base that allows a large hole in the hood and can still be sealed and shaped as to achieve "ideal entry" into the carb. Good luck at the race. Still snow here you lucky devil.

[wyoming 64savoy]

Speaking of sealing te scoop, does any one know of a good source for the heavy duty flame retardent foam. All the catalogs have is a air pan with foam, but I'm just looking for the foam. Seems all I can ever find is the cheap walmart stuff.

[Christopher]

I use regular A/C line insulation. It's easily obtaiable at Home Depot,and attaches to sheet metal air pans using 3M weatherstrip adhesive.Most foam is open cell and actually allows hot underhood air to enter.The A/C line insulation comes in many sizes,and I don't cut it,I just glue it to the air pan and leave it in it's round shape.

[Rob Campbell]

Thanks CUDA367 for the info on sealing the scoop to the Carb.

I have since read an article in my Holley book which confuses the issue somewhat.

The article states "the scoop roof should be positioned 1-1-1/2" above the carburetor inlet. Any more clearance may create detrimental turbulence and any less restricts airflow into the carburetor.

Whereas the Mopar bulletin states that the main objective was to keep the top of the carb 1/2" below the floor of the scoop.

I am running a dominator 1050 on a M1 manifold using a 2" spacer.

The carburetor sits well above the hood however I have a fiberglass hood with the scoop glassed onto it.

I have installed an aluminum floor in the scoop with a cutout to match the diameter of the carburetor.

The top of the carburetor is approximately 6.5 inches below the roof of the scoop and 2.5" below the floor of the scoop.

Sound like I may have to reduce the height of the scoop by 5 inches or so.

Any help appreciated.

[cuda367]

Who am I to argue with holly. I would be very afraid of having only 1 to 1 1/2 inches of air above the carb. If I was to due your set up, I would only lower the scoop about an inch or so depending on the actual measurements to set the top of the card 1/2 to 3/4 inches below the floor of the scope. Ideally I would still want to install some type of Ideal entry base on top of the carb. We did a scoop for our super comp dragster using the Barry Grant base I mentioned as a starting point. Worked very well. Have Fun

[Rob Campbell]

Thanks for the advice.

I will give it a go and see what happens.

Cheers