Cowl induction benefits - Page 8 - Chevelle Tech
Chevelle Tech General Tech Area
Please try and post in specific forums

 93Likes
Reply
 
LinkBack Thread Tools Search this Thread Display Modes
post #106 of 125 (permalink) Old Jul 9th, 19, 9:31 AM
Senior Tech Team
 
Join Date: Nov 2008
Location: Chevelle land USA
Posts: 1,911
Re: Cowl induction benefits

I tried what someone else was talking about earlier in this thread regarding "moving" the elec solenoid forward to hold inner door open.

Well the power wire "spade" wont allow the solenoid to be "pushed" far enough forward to hold the inner door open fully.

So,
I simply popped off the "hinges" which allowed me to remove the inner door completely so its wide open all the time now. In order to make it truly outside air only I blocked off the CI air cleaner "snorkel" so it wont ingest any under hood hot air only outside air which is substantially cooler.

Marc S


71 SS 454 ELCO
Edelbrock Proflo4
TKO600
Strange 12bolt w/4.10
1971ss454Elco is offline  
Sponsored Links
Advertisement
 
post #107 of 125 (permalink) Old Jul 10th, 19, 7:50 AM
Tech Team
 
Join Date: May 2005
Posts: 390
Re: Cowl induction benefits

Good idea i would say the engine is pretty much just drinking outside are.And when your moving your getting a draft of outside air to the top of that air cleaner
ranvette is offline  
post #108 of 125 (permalink) Old Jul 10th, 19, 9:29 AM
Tech Team
Harry
 
Join Date: Jan 2011
Location: Los Angeles
Posts: 314
Re: Cowl induction benefits

Quote:
Originally Posted by 1971ss454Elco View Post
I tried what someone else was talking about earlier in this thread regarding "moving" the elec solenoid forward to hold inner door open.

Well the power wire "spade" wont allow the solenoid to be "pushed" far enough forward to hold the inner door open fully.

So,
I simply popped off the "hinges" which allowed me to remove the inner door completely so its wide open all the time now. In order to make it truly outside air only I blocked off the CI air cleaner "snorkel" so it wont ingest any under hood hot air only outside air which is substantially cooler.
I just bent the spade back 90 degrees and moved it forward and clamped it. I still kept it plugged in. I unplugged it at the gas pedal.

Harry
1970 Chevelle SS396 (408), Fathom Blue,
Original Block & Forged Crank, KB Pistons, Edelbrock 6045 Heads,Comp Cam 292H, March Serpentine, RPM AirGap,750HP,100hp Nitrous
A/F Wideband,Tremec TKO 600, 12 bolt,
30 spline Moser Axles, Richmond 3:73's, Hotchkis control arms, swaybars, springs, Wilwood 12" rotors D/S, 4 piston calipers
hjdca is offline  
 
post #109 of 125 (permalink) Old Jul 10th, 19, 10:31 AM
Lifetime Premium Member
 
Join Date: Jul 2000
Location: Northeast New Jersey
Posts: 8,311
Garage
Re: Cowl induction benefits

Quote:
Originally Posted by 71350SS View Post
Here you go Tom, all the way back in the late 50's on the road race Corvette's called the air box cars.I don't know if this is the first but this is pretty early for this kind of option,its a 1957 Corvette.

https://www.hagerty.com/articles-vid...irbox-corvette

The 283 Fuelie engine was rated at one HP per cube but the air box cars were about 300 HP per the article.
Chevy's first time with a factory cold air option for the engine was in 1957 on the air box Corvette's.This was a race only option and required a bunch of racer type options intended mostly for road race style cars not really suited for drag racing or Nascar. Required were Fuel injection 4 speed trans positraction rear and radio and heater delete which made some other things posible.This was so the Corvettes could compete against the Jags and Ferrari's of the day.
That's 1957, so the Chevy engineers knew what to expect from cold air induction on the cowl hoods of the 1970's.

John
71 El Camino SS
406 SBC M21 3.31 12 bolt
"Quality is always remembered,long after the price is forgotten"
"I would rather have questions I can't answer than have answers I can't question" :R.Feynman
71350SS is offline  
post #110 of 125 (permalink) Old Jul 10th, 19, 11:35 AM
Senior Tech Team
 
Join Date: Nov 2008
Location: Chevelle land USA
Posts: 1,911
Re: Cowl induction benefits

Quote:
Originally Posted by hjdca View Post
I just bent the spade back 90 degrees and moved it forward and clamped it. I still kept it plugged in. I unplugged it at the gas pedal.
hummmm.

Marc S


71 SS 454 ELCO
Edelbrock Proflo4
TKO600
Strange 12bolt w/4.10
1971ss454Elco is offline  
post #111 of 125 (permalink) Old Jul 11th, 19, 9:19 PM
Tech Team
 
Join Date: May 2005
Posts: 390
Re: Cowl induction benefits

I would buy it would make up to 17 HP more.But depending on temps outside and all that sort of thing.In other words there is a Little power there. But a varying amount.
ranvette is offline  
post #112 of 125 (permalink) Old Jul 13th, 19, 9:46 AM
Tech Team
 
Join Date: May 2005
Posts: 390
Re: Cowl induction benefits

This is interesting to.I think most of us must have felt the flow threw astro ventilation vents over the years when there on.A nice little breeze while the car is moving.That is about the same breeze a cowl induction entrance would have.With the car moving.The source for those vents is in the cowl.
Attached Thumbnails
Click image for larger version

Name:	NONair_vent.jpg
Views:	5
Size:	101.2 KB
ID:	598176  
ranvette is offline  
post #113 of 125 (permalink) Old Jul 13th, 19, 10:48 AM
Gold Founding Member
 
Join Date: Aug 1998
Location: 30.1298228, -97.9771166
Posts: 6,799
Garage
Re: Cowl induction benefits

Quote:
Originally Posted by ranvette View Post
This is interesting to.I think most of us must have felt the flow threw astro ventilation vents over the years when there on.A nice little breeze while the car is moving.That is about the same breeze a cowl induction entrance would have.With the car moving.The source for those vents is in the cowl.
What happens to the force of the ‘breeze’ when the flapper on top opens?

The biggest problem facing America today is that lies are so widely accepted as truths.
Alan F is offline  
post #114 of 125 (permalink) Old Jul 13th, 19, 12:09 PM
Tech Team
 
Join Date: May 2005
Posts: 390
Re: Cowl induction benefits

I would say by the way my 3 pieces of ribbon were pulled flat to the screen at full throttle.And this was from 4000 to 5600 rpm.The air is drawn faster than its breeze.(A able to pull by demand type system)Makes sense there is a good amount of air being inhaled by a 396 turning higher rpms.With my K&N filter there is a lot of intake noise as well when that door opens.And the dynomax super turbo mufflers/and headers are just right to still hear plenty of intake noise.A side note the vac door is not as active on my auto as a 4 speed.Unless i force the engine to bog before a down shift.So durring my ribbon test that door was about a 1/4 way open
ranvette is offline  
post #115 of 125 (permalink) Old Jul 13th, 19, 12:20 PM
blm
Lifetime Premium Member
Brad
 
Join Date: Sep 2002
Location: McDonald Pennsylvania
Posts: 11,284
Garage
Re: Cowl induction benefits

Quote:
Originally Posted by ranvette View Post
This is interesting to.I think most of us must have felt the flow threw astro ventilation vents over the years when there on.A nice little breeze while the car is moving.That is about the same breeze a cowl induction entrance would have.With the car moving.The source for those vents is in the cowl.
This is comparing apples to oranges. Astro Ventilation works off a ram air principal. Cowl Induction doesnt work off ram air it works off vacuum.
An engine with a big cam is going to produce less vacuum at a certain rpm than a smaller cammed engine. Two different Chevelles traveling at the same speed are going to experience the same pressure at the cowl. Vacuum vs ram effect.
blm is offline  
post #116 of 125 (permalink) Old Jul 13th, 19, 3:57 PM
Tech Team
 
Join Date: May 2005
Posts: 390
Re: Cowl induction benefits

The air supply to the vents in a chevelle(a none ac car) is from the cowl.Not ram air forced into the openings.On left and right side of the cowl.
ranvette is offline  
post #117 of 125 (permalink) Old Jul 14th, 19, 10:30 AM
Tech Team
Harry
 
Join Date: Jan 2011
Location: Los Angeles
Posts: 314
Re: Cowl induction benefits

Quote:
Originally Posted by ranvette View Post
I would say by the way my 3 pieces of ribbon were pulled flat to the screen at full throttle.And this was from 4000 to 5600 rpm.The air is drawn faster than its breeze.(A able to pull by demand type system)Makes sense there is a good amount of air being inhaled by a 396 turning higher rpms.With my K&N filter there is a lot of intake noise as well when that door opens.And the dynomax super turbo mufflers/and headers are just right to still hear plenty of intake noise.A side note the vac door is not as active on my auto as a 4 speed.Unless i force the engine to bog before a down shift.So durring my ribbon test that door was about a 1/4 way open
Two things greatly control the action of the top cowl hood flapper:
The one way check valve hooked up to the vacuum which opens the flapper door and allows it to close slowly. If you get rid of that one way check valve, then, the door opens quickly and closes quickly.
In addition, there is a piece that rests on the vacuum canister that is connected by one screw to the flapper. If you adjust the tension of this one screw and the orientation of the piece on the vacuum can (forward or back), you can adjust the action and opening and closing clearances of the flapper.

Harry
1970 Chevelle SS396 (408), Fathom Blue,
Original Block & Forged Crank, KB Pistons, Edelbrock 6045 Heads,Comp Cam 292H, March Serpentine, RPM AirGap,750HP,100hp Nitrous
A/F Wideband,Tremec TKO 600, 12 bolt,
30 spline Moser Axles, Richmond 3:73's, Hotchkis control arms, swaybars, springs, Wilwood 12" rotors D/S, 4 piston calipers
hjdca is offline  
post #118 of 125 (permalink) Old Jul 15th, 19, 1:45 AM
Team Member
John
 
Join Date: Jul 2016
Location: Huntsville, AL
Posts: 176
Garage
Re: Cowl induction benefits

The infamous Car and Driver 1964 GTO Road test car that was provided by Pontiac Motor Division also had an opening from the cowl vent through the firewall above the heater box to a sealed air cleaner. The 67 Camaro Z/28 also pulled air from an opening in the firewall that got air from the base of the windshield, this was before the infamous 69 model Cowl Induction hood. The area at the base of the windshield is a source of high pressure, the OEM's knew that, NASCAR knew it also. That being said, I believe my 70 Cowl Induction is more of a gimmick than a real performance enhancer. What I enjoy about them is when people tell me mine works "backwards" because "it's supposed to flip open when you hammer it" I just kinda laugh...

70 El Camino SS 396/TH400
67 Cutlass Supreme convert LS3/4LE85
65 GTO convert Tri Power 4 speed
65 Corvair Corsa Crown Conversion (Mid engine 350)
05 Silverado 2500 Duramax/Allison
06 GTO 6 speed
11 Honda Accord 6 speed coupe
14 Harley Davidson Electra Glide Ultra Limited
19sixty5 is offline  
post #119 of 125 (permalink) Old Jul 15th, 19, 8:24 AM
blm
Lifetime Premium Member
Brad
 
Join Date: Sep 2002
Location: McDonald Pennsylvania
Posts: 11,284
Garage
Re: Cowl induction benefits

Quote:
Originally Posted by ranvette View Post
The air supply to the vents in a chevelle(a none ac car) is from the cowl.Not ram air forced into the openings.On left and right side of the cowl.
So I guess the air going into the Astro Ventilation is not produced by the effect of the vehicle traveling at a speed and having an opening to collect air from the pressure that the traveling creates ( ram air) I guess it happens by magic.
Same thing as rolling your window down. (Ram air)
blm is offline  
post #120 of 125 (permalink) Old Jul 15th, 19, 12:51 PM
Tech Team
 
Join Date: May 2005
Posts: 390
Re: Cowl induction benefits

Its by the air pressure in the cowl.Down flow into cowl.I guess you consider that ram air.I guess cowl induction would be ram air to.By what ever principle you choose air is forced into those vents
ranvette is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Chevelle Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address. Note, you will be sent a confirmation request to this address.

Email Address:
OR

Log-in










Thread Tools Search this Thread
Show Printable Version Show Printable Version
Email this Page Email this Page
Search this Thread:

Advanced Search
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Trying to track down additional 1972 SS 454 Real "W" Convertibles skryla Convertibles 728 Feb 21st, 18 2:22 PM
Cowl induction hood versus non cowl induction appearance mersol Body Shop 11 Jan 17th, 17 11:32 PM
New to Forum w/1972 SS 454 4 Speed Vert elliet1964 New Member Introductions 14 Aug 7th, 16 6:00 PM
70 Chevelle Cowl Induction Hood jjr158 Troubleshooting 24 Sep 24th, 15 8:12 PM
issues with cowl induction on 72 Chevelle 69Chevelle396/375 Troubleshooting 3 Sep 2nd, 13 9:00 AM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome