Currently have a flat steel hood on my 69 Dart
Wondering if going to a fiberglass hemi Dart hood would show any decent gains with good airpan on a mid 11 sec car.

Back when my duster was going 12.00's I cut the steel hood and installed a bolt on 6 pack scoop. I didn't make a pan to seal the carb to the scoop but it didn't seem to make real big ET difference. (might of picked up a few hundredths at most). The only difference I noticed was the car did seem to run just a tad cooler. I ended up making more changes in the weeks after that so I didn't have many weeks of the same combo to make a comparison to.

Any carb sucking hot under-hood air can benefit from cooler outside air and I always picked up but had to make tuning changes.....Then there's turbulence in some cases where the WRONG scoop can play havoc on bowl vents actually pulling fuel out of the bowls at speed etc..........

Low 11-second car with hood scoop , but no sealed air pan, picked up a tenth in ET and 1+ MPH with the addition of a sealed air pan. The open scoop by itself didn't really do much.

Way back when I just started, bottom 12sec sb, 70 dart, put a 4.5 tall 6pack scoop on and sealed to carb, went 1.5 tenths and 1.5mph faster. Huge gain to me

I was going to say the same thing and have a couple of things to add:

* Any results you see can also depend on how the car is jetted to begin with. If it's a little rich, it can pick up. If it's a little lean, it may not help, or hurt.

* Underhood air is more "consistent" than scooped outside air. In theory, a car without a scoop will be a bit more consistent/predictable than with a scoop. I had a friend & VG bracket racer who actually blocked off his '68 Cuda scoop with clear plexiglass.

* Another friend had a '65 Plymouth with a correct Hemi style scoop over the 360 that occasionally did weird things. After unsealing the carb with vents in the foam, the problem went away. Inconsistent turbulence was the only thing we could think of.

When I was running mid 11s, my car dropped a tenth and gained 1.5 mph just by sealing up the 6 pack hood scoop to the carb. Has to be worth more than that compared to a flat hood.

I run EFI but It is through a 4150 throttle body located just like a carb. I run a stock hood and I log intake air temp(at the inlet of the TB). I have seen intake temps on the starting line as high as 140-150 degrees, and it cools off during the run as it jams the engine compartment with fresher air but it still is over 110* at the stripe. I plan on going fresh air soon but it will be part of a tunnel ram project I am working on so it won't be apples to apples. But I promise going from 140* temps to whatever is outside will gain power.

How fast does your AT sensor measure air temp changes do you think or know?

I was talking to a buddy with a '71 Demon stocker last year and noticed he had the hood scoops sealed off. He said they picked up almost a tenth after closing them off.

I don't know for sure, it is a GM sensor that is platic and mounted in a rubber grommet to prevent heat soak(its part of the holley throttle body)

It reacts reasonably quick when the air is moving quickly over it. I will see if I can find a log to post a picture of the slope from starting line to finish line.

My thoughts are directing the air right like the ones above said then getting the fuel mixture right. Stick your hand out the window running 70 or above, get the air going in right, gotta help. A person can't stand up at 100 mph, that's a lot of pressure.

Some have said I'll go slower with this but I will try it back to back V's 2x 9x5 air filters in 4 weeks.

From the factory the 71 Demon scoops were never open to the engine. They are just extra weight on the front of the car. The 72 with the sizzler scoop did have openings ducting air into the engine compartment but not sealed to the carb. On my Demon I never saw any difference with the scoop or not. I just liked the looks of the scoop.

A friends AAR runs quicker/faster with the hood not sealed to the carbs. The TA is a different story it runs better with the hood sealed.

IMO, yes and run a pan with a seal. The 340 was in when I put the hood on, it picked up but honestly I don't remember how much.

My Dart has a A&A six pack hood on it and I've had three small blocks in it in the last 12-13 years and all have ran better sealed up. I did back to back tests on the 408 and the 434 with and without the pan. The car lost et everywhere, even 60', it may have been different had I messed with the jetting for no pan.

On another note my car runs cooler on the street without the pan.

There are round holes under each scoop. My Swinger had the same hood, and even had rubber rings on the holes.

Back in the 70s early 80s the plastic paper boxes were the rage. We just cut two holes in the bottom to set down on the carbs like you have there. Almost every car had them, don't know why they worked but did. Simple and cheap.

when I sealed up my carb to my 1970 Road Runner type hood , I had to retune my carb, also AFR is more consistent, the car runs much better with it sealed up,my car has ac & in southeast Tx, so under hood temps are very high, it really runs like a different car, for the better.

Hey, CSK, ever go to the barbecue place by the Katy IGA store next to the RR tracks? They used to be great, 10 years ago or so.

Two thoughts on hood scoops:
1. Most of the gains you will see, if any, come from the engine getting cooler air. The ram effect is much less than you'd expect.

2. It can screw up the carbs metering to have air going sideways at the entrance. Most downdraft carbs work the best with the air going straight into the carb.

Your mileage may vary.

R.

There is Midway BBQ , I dont remember the name of the other BBQ place, but they are gone. Midway is very good !!!