Anyone actually test the effects of raising the back of the hood?

[afret]

I did that long ago to let the hot air out but since then found out that is backwards and air is supposed to flow in from the high pressure cowl area.  Has anyone tested how much actual airflow there is into the engine compartment if the rear of the hood is raised a bit?

[machoneman]

Nope! But my first car (no kidding) in 1971 was a super clean '67 SS Camaro with a closed chamber 427 BBC, Hookers, M-22, 4:88 gears and it flew! The previous owner had propped the back of the hood up with flat washers and longer bolts to allow more airflow. I removed same....and quickly learned a lesson in underhood air flow! The temps went up at least 12-15 degrees on a warm-to-hot summer day and I quickly added the washers back on.     

Btw, to add another comment, the car at rest at a stoplight would heat up damn quick (uncoated headers the big culprit) so airflow at the cowl/windshield wasn't even a factor OR concern. Today, my '70 Stang has Jet-Hot silver coated race type Hookers (358 SBF at about 490 HP) and they make an immense difference in lowering dramatically underhood heat. Wish I had that coating option in the 1970's! 

[Falcon67]

No, but for a mild 351C the difference between under hood air and air from a sealed scoop facing the windshield was .3 ET and 3 MPH in the 1/8 mile.  So for a  basic question like "is outside air worth the effort" the answer is yes, big time.

[afret]

No, but for a mild 351C the difference between under hood air and air from a sealed scoop facing the windshield was .3 ET and 3 MPH in the 1/8 mile.  So for a  basic question like "is outside air worth the effort" the answer is yes, big time.

Had about the same improvement in the 1/4 with my street car when I sealed the carb to the scoop.

[Posi67]

It used to be pretty common back in the 70's but you don't see much of it anymore other than possibly hood to carb clearance. No idea if it works but may not be legal in Stock class anymore. Better check on that though.

As for sealing the carbs to the hood... well, I read and heard how much that helped so got all excited about picking up some easy ET and MPH. Saw absolutely nothing on 3 different 2x4 FE's and several versions of each. Mostly just tries to rip the hood off the car. I'll try my pan again this season with very little anticipation of going faster. Others results may vary.

[My427stang]

I think anything that allows air in OR out of a shock tower car should help.  The rear of the engine on a FE shock tower car can hold a lot of heat.  Add air in to let it flow downward under the car, or let heat out when staging or idling around the pits, all good IMHO, even if it's just to keep your feet cool

I'd say the addition of a small spoiler up front would help too as it should add to the low pressure area under the car at speed, compounding what it will evacuate

[fryedaddy]

i need some of those coated headers.my hookers are 30+years old and they are thin.i think the thin wore out headers heat up even more.i took my inserts out of my 66 cyclone hood and cut out the holes to try to get some cooler air in and i didnt notice any difference.im going to have to invest in some quality coated headers.i believe that would help more than anything

[My427stang]

If they are decent, 175.00 bucks will have them coated and likely better than what you'll buy from a big box company