SpoolingTurbo6
Donating Member
What all kinds are out there? I kind of like the C5
anyone found one that looks good on a Cowl Hood?
anyone found one that looks good on a Cowl Hood?
What does anyone know about " heat extcracting hoods" ?
- Thread starter SpoolingTurbo6
- Start date
SYO237
SyTy Registry
Re: What does anyone know about " heat extcracting hoods" ?
correct me if im wrong here...
A typical cowl hood and the way its shaped creates a low pressure point right at the bottom of the windshield which helps suction out the hot air under the hood. So you have to be moving in order to make the cowl worthwhile.
Now, if the above is true, has anyone ever tried to measure different cowls? With our trucks being shaped like a brick, most of the air hits the front end and deflects up and over the cab and out the sides. This can be seen if you have a dirty truck and your caught in the rain then let the truck dry off... you can sometimes see the water streaks sneaking up the front edge of the hood to about 4-5 inches back. The farther you move out to the fenders, you can see the aiflow start to take a hard left or right curve off towards the fender depending which side your looking at.
I have a standard 2.5" Harwood fiberglass that I would consider more for looks than function. It does more waving at high speed than moving air I would assume.. and at a stand still you dont feel to much hot air just coming out to help cool off.
Ian Turgeon is using 2 Z34 Lumina vents mounted just above the turbo and over the alternator. As far as driving around, temps are average...its when the truck sits to cool down is where he benefits the most... hot air just goes straight up and out, cools off quick.
Id be interested to see what cowl design would actually work to our benefit.
correct me if im wrong here...
A typical cowl hood and the way its shaped creates a low pressure point right at the bottom of the windshield which helps suction out the hot air under the hood. So you have to be moving in order to make the cowl worthwhile.
Now, if the above is true, has anyone ever tried to measure different cowls? With our trucks being shaped like a brick, most of the air hits the front end and deflects up and over the cab and out the sides. This can be seen if you have a dirty truck and your caught in the rain then let the truck dry off... you can sometimes see the water streaks sneaking up the front edge of the hood to about 4-5 inches back. The farther you move out to the fenders, you can see the aiflow start to take a hard left or right curve off towards the fender depending which side your looking at.
I have a standard 2.5" Harwood fiberglass that I would consider more for looks than function. It does more waving at high speed than moving air I would assume.. and at a stand still you dont feel to much hot air just coming out to help cool off.
Ian Turgeon is using 2 Z34 Lumina vents mounted just above the turbo and over the alternator. As far as driving around, temps are average...its when the truck sits to cool down is where he benefits the most... hot air just goes straight up and out, cools off quick.
Id be interested to see what cowl design would actually work to our benefit.
crashing_sux
Blow Me?
Re: What does anyone know about " heat extcracting hoods" ?
Close but backwards, there is a high pressure point at the base of your windshield, the cowl is just giving that air a way to escape into your engine bay. At speed, air isn't coming out of it, but being forced into it.
Close but backwards, there is a high pressure point at the base of your windshield, the cowl is just giving that air a way to escape into your engine bay. At speed, air isn't coming out of it, but being forced into it.
SY2455
70's Veteran
Re: What does anyone know about " heat extcracting hoods" ?
The only one I know of is located here.
http://www.up22.com/S10.htm
Part # GM 804B
The only one I know of is located here.
http://www.up22.com/S10.htm
Part # GM 804B
Robert Lone
MUTANT
Re: What does anyone know about " heat extcracting hoods" ?
I had a Z-34 vent turned sideways on my hood. At speed it blew fresh air on my (now retired) turbo. Reason being w/ the custom headers that were on my truck, the turbo was 1/4" from the A/C compressor. Without the vent, the compressor only lasted for an hour or so on the interstate. It looked like crap, but it cooled the trubo like gangbusters! The big downside to my setup was that the faster I went, the more air pressure was trapped in the front clip.
I had a Z-34 vent turned sideways on my hood. At speed it blew fresh air on my (now retired) turbo. Reason being w/ the custom headers that were on my truck, the turbo was 1/4" from the A/C compressor. Without the vent, the compressor only lasted for an hour or so on the interstate. It looked like crap, but it cooled the trubo like gangbusters! The big downside to my setup was that the faster I went, the more air pressure was trapped in the front clip.
turbodog
Donating Member
Re: What does anyone know about " heat extcracting hoods" ?
Yeah. I put a 2 " cowl hood on because it was convenient at the time (thanks again, Servando), but now I realize that it may in fact reduce cooling flow thru the A/C condenser, Aux CCHE's and radiator. This is because this cooling flow depends on a pressure difference from the front of the grille to the engine compartment. By venting high pressure air from the base of the windshield to the engine comaprtment, I am increasing the pressure in the engine compartment. The original intent for this hood design (a'la early 70's Chevelle) was to route this high pressure air into the engine, not the engine compartment. May not be a significant change, but who knows....
There is likely a low pressure area just behind the leading edge of the hood. But, go too far back toward the windshield, and it becomes a high pressure area as the air displaced by our barn-door front grille comes back down onto the hood. Hard to know where the sweet spot is (tape 100 little pieces of yarn on and go for a drive?)
Yeah. I put a 2 " cowl hood on because it was convenient at the time (thanks again, Servando), but now I realize that it may in fact reduce cooling flow thru the A/C condenser, Aux CCHE's and radiator. This is because this cooling flow depends on a pressure difference from the front of the grille to the engine compartment. By venting high pressure air from the base of the windshield to the engine comaprtment, I am increasing the pressure in the engine compartment. The original intent for this hood design (a'la early 70's Chevelle) was to route this high pressure air into the engine, not the engine compartment. May not be a significant change, but who knows....
There is likely a low pressure area just behind the leading edge of the hood. But, go too far back toward the windshield, and it becomes a high pressure area as the air displaced by our barn-door front grille comes back down onto the hood. Hard to know where the sweet spot is (tape 100 little pieces of yarn on and go for a drive?)
blk00z28
Forced to by choice
Re: What does anyone know about " heat extcracting hoods" ?
There was a good write up on the TurboBuick.com website a few months ago about fan's on the GNX style vents. And how much it helped in the engine bay. I'm trying to find the link right now, but why not something like this? I cant for the life of me find this thread, but I believe he used some computer fans on it. It looked like a good setup.
I would think this would help out tremendously in the engine bay.
There was a good write up on the TurboBuick.com website a few months ago about fan's on the GNX style vents. And how much it helped in the engine bay. I'm trying to find the link right now, but why not something like this? I cant for the life of me find this thread, but I believe he used some computer fans on it. It looked like a good setup.
I would think this would help out tremendously in the engine bay.
leadfoot
Member
Re: What does anyone know about " heat extcracting hoods" ?
I think the original intent of the cowl hood was to pull that cool air into the engine compartment directly to the air cleaner (while in motion). The better hoods actually sealed to the air cleaner so that the air was exclusive for the carb.
Over the years, the tradition cowl hood has been more of a aesthetic issue rather than functionality. However, when parked I would think the cowl would simply allow the compartment to vent by basic thermal physics (heat rises) so it would have some use in the modern automobile.
I think the original intent of the cowl hood was to pull that cool air into the engine compartment directly to the air cleaner (while in motion). The better hoods actually sealed to the air cleaner so that the air was exclusive for the carb.
Over the years, the tradition cowl hood has been more of a aesthetic issue rather than functionality. However, when parked I would think the cowl would simply allow the compartment to vent by basic thermal physics (heat rises) so it would have some use in the modern automobile.
SY2455
70's Veteran
Re: What does anyone know about " heat extcracting hoods" ?
You are right the cowl hood was made to pull air into the carb, in a write up that Year One Inc did they show the factory testing that was done on the 69 Camaro it added like 27hp at 6000 rpm. They had to add a solenoid and a flap to close off the cowl area because during cold temperatures it would cause a icing problem for the carb, like they have on airplanes. The flap would stay close up to 3/4 throttle. The 69 SS I gave to my son has this setup. If I can find the Year One write up I'll post for you, It out in the garage somewhere with everything else.
leadfoot said:
You are right the cowl hood was made to pull air into the carb, in a write up that Year One Inc did they show the factory testing that was done on the 69 Camaro it added like 27hp at 6000 rpm. They had to add a solenoid and a flap to close off the cowl area because during cold temperatures it would cause a icing problem for the carb, like they have on airplanes. The flap would stay close up to 3/4 throttle. The 69 SS I gave to my son has this setup. If I can find the Year One write up I'll post for you, It out in the garage somewhere with everything else.
blk00z28
Forced to by choice
Re: What does anyone know about " heat extcracting hoods" ?
BTW, here is that link I was talking about.
http://www.turbobuicks.com/forums/showthread.php?t=33467
BTW, here is that link I was talking about.
http://www.turbobuicks.com/forums/showthread.php?t=33467
NateP
Money Pit Member
Re: What does anyone know about " heat extcracting hoods" ?
Anyone ever lined their hood with a heat extracting material such as transfer silicone? We mounted some of this stuff on robot/molding machine where the part/mold face were super hot. The idea behind the stuff is that it gets "excited" easily ie takes heat away, and disposes of it quickly.
The idea would be (if a hood with scoop was used) that the layer engine side down would pick up the heat, the upside would be in contact with cool air and disappate the heat.
Our system sucks the heat off the mold face, transfers a graphic to the cooled mold, then as the robot traverses, the padding is cooled by the air passing over it. It goes from 400 degrees or so, down to 100 or so in about 30 seconds, traveling at approx 1ft per second.
or maybe Im way off base here... just a thought I had
Nate
Anyone ever lined their hood with a heat extracting material such as transfer silicone? We mounted some of this stuff on robot/molding machine where the part/mold face were super hot. The idea behind the stuff is that it gets "excited" easily ie takes heat away, and disposes of it quickly.
The idea would be (if a hood with scoop was used) that the layer engine side down would pick up the heat, the upside would be in contact with cool air and disappate the heat.
Our system sucks the heat off the mold face, transfers a graphic to the cooled mold, then as the robot traverses, the padding is cooled by the air passing over it. It goes from 400 degrees or so, down to 100 or so in about 30 seconds, traveling at approx 1ft per second.
or maybe Im way off base here... just a thought I had
Nate
SY2455
70's Veteran
Re: What does anyone know about " heat extcracting hoods" ?
On the 69 Camaro they use a solenoid and what a pain as the solenoid kept shorting out or burning up, I was told that why they went to a vacuum setup in 1970, like Oldsmobile use on the W-30 and Hurst/Olds 1969-1972
blk00z28 said:
On the 69 Camaro they use a solenoid and what a pain as the solenoid kept shorting out or burning up, I was told that why they went to a vacuum setup in 1970, like Oldsmobile use on the W-30 and Hurst/Olds 1969-1972
SpoolingTurbo6
Donating Member
Re: What does anyone know about " heat extcracting hoods" ?
A few pics I found. Under *heat extracting hood* click for large image
A few pics I found. Under *heat extracting hood* click for large image
SpoolingTurbo6
Donating Member
Re: What does anyone know about " heat extcracting hoods" ?
OK guys I'll give you all a sneekpeek of my hood being built.
Give me a while and I'll have more photos
OK guys I'll give you all a sneekpeek of my hood being built.
Give me a while and I'll have more photos