hoodscoop

[1970 La]

i was at the track last weekend running my car with out the air cleaner. about midway it was not pulling right. i have a six pack hood with no tray on top of the carb. the hood has always raised in the middle on the big end could the air coming through the scoop and out the back of my hood be pulling the gas out of my ventures? i put the air cleaner on it and it ran faster. i would think it would run faster with it off.

 

[rklein383]

Air cleaner probably allows for a smoother air flow into the carb.

 

[daredevil]

you already figured it out. Its not pulling fuel out of the carb but decreasing the signal and leaning it out. Try it with a short air horn and you should see improvement.

 

[1970 La]

it was leaning out the carb i had 86 90 jets in it. never had to be jetted this much but always ran the air filter before.

 

[daredevil]

Sounds like i hit the nail on the head. A short stack will let the air settle and flow right instead of loosing vaccuum signal

 

[Locomotion]

Scoops and sealed air pans can do weird things because of air flow turbulence. I had a friend with a '65 Satellite with a 360 and Hemi scoop on it. It ran well, but not as consistent as it could, and once in a while, it would run way off. All he did was cut some openings (vents) in the seal between the scoop and air pan and the problem went away!

Always re-tune the carb whenever you change anything like that.