'65 mopar hemi hood scoop

House of Darts · 08-16-2011, 01:05 AM

Over the last few years I have measured the openings of either original or aftermarket SS/ Hemi hood scoops. They range from 1 1/8" to 1 1/2" in height.Does the 1 1/2" height really make any more HP with the scoop than without? I came across an old Mopar tech paper that says that 1 1/2" above the hood is just dead air. Any real testing on this factory height and the HP it makes? I have not seen any SS/B or C cars that don't use the scoop. Thanks

GTX JOHN · 08-16-2011, 04:42 AM

Carbs are pretty close to Hood without scoop. Back in 60s I raced a SS/CA
car and saw a lot of reversion on hood above carbs without scoop. I ended up lowering the engine an extra inch and half and it seemed to help. Today I do not like less than 2 inches or more if possible between carbs and Hood.

Just an opinion no empirical testing or evidence.

Jim B · 08-16-2011, 06:36 AM

GTX JOHN is correct about providing carb air horn vertical clearance. A big advantage to the mid 60's Chrysler scoop design was to provide outside (cooler) air to the engine. Sealing the carbs to the hood plate is important to take advantage of this. Guys used to use longer vertical scoop support sleeves to bow the scoop up in the middle and had to remove them when other racers complained. Didn't seem to slow the car down any when they were changed to the proper length. Guys used to jack the back of the hood up (both to give the scoop a better angle of attack and to provide better underhood cooling) and the biggest noticeable difference was a bit better engine cooling in some applications. Once again, racer complaints made them align the hood better. The bent front license plate was an attempt to provide better air flow but I think it was really an attempt to make a shoebox (body style) more aerodynamic. I do remember the genuine Chrysler metal (both sheet metal and aluminum) scoops were always somewhat taller than any of the aftermarket offerings. The '68 hemi A bodies used a taller (about 4") top flared scoop that provided a measureable positive pressure inside the scoop that was not attainable in the earlier "B" bodies but that's not comparing apples to apples. My 2¢... BTW were there any SS/B or SS/C combos that weren't factory equipped with scoops? I don't remember any factory B body SS combos with a flat hood hemi.

Phillip marvetz · 08-16-2011, 10:32 AM

The 64-65 scoops are different from the 67 scoops also, Although I have been told it is allowable to use the 67 scoop on a 64-65.

[QUOTE "empirical" [/QUOTE]

Nice word John, I'm going to use that one somehow today. How have you been?

GTX JOHN · 08-16-2011, 03:55 PM

My SS/CA Car was 68 Roadrunner with 426 Street Hemi with Rat Toaster Manifold......Back then the only Mopar that ran the class as weight could not
be adjusted at all from shipping weight in the early days. Car was purchased from Mike Loge possibly when Chad was in Diapers.

Phillip: I underwent another surgery about a month ago but I am healing well
and all Cancer was successfully excised. I will be racing @ Vegas! Good Lord willing!

Dwight Southerland · 08-16-2011, 04:31 PM

What's the difference between a "Rat Toaster" manifold and a "Rat Roaster" manifold? One is crispy on the outside?

GTX JOHN · 08-17-2011, 03:48 AM

Pretty much is a question of how Well Done you prefer the Rats.........The Rat Toaster keeps them a bit more crispy on the outside and still squishy on the inside.

I have a couple in the shop available for purchase of each......Manifolds that is
as the Rats do not keep well after cooked.

GTX John ( Lost Glasses in Lake Sunday and I am sorry for my proof reading )

08-16-2011, 01:05 AM	#1
House of Darts Member Join Date: Mar 2007 Posts: 346 Likes: 19 Liked 20 Times in 15 Posts	'65 mopar hemi hood scoop Over the last few years I have measured the openings of either original or aftermarket SS/ Hemi hood scoops. They range from 1 1/8" to 1 1/2" in height.Does the 1 1/2" height really make any more HP with the scoop than without? I came across an old Mopar tech paper that says that 1 1/2" above the hood is just dead air. Any real testing on this factory height and the HP it makes? I have not seen any SS/B or C cars that don't use the scoop. Thanks

08-16-2011, 04:42 AM	#2
GTX JOHN VIP Member Join Date: Jun 2009 Location: Boulder City, Nevada 89005 Posts: 2,538 Likes: 2,238 Liked 1,876 Times in 578 Posts	Re: '65 mopar hemi hood scoop Carbs are pretty close to Hood without scoop. Back in 60s I raced a SS/CA car and saw a lot of reversion on hood above carbs without scoop. I ended up lowering the engine an extra inch and half and it seemed to help. Today I do not like less than 2 inches or more if possible between carbs and Hood. Just an opinion no empirical testing or evidence.

08-16-2011, 06:36 AM	#3
Jim B Member Join Date: Dec 2008 Posts: 100 Likes: 0 Liked 1 Time in 1 Post	Re: '65 mopar hemi hood scoop GTX JOHN is correct about providing carb air horn vertical clearance. A big advantage to the mid 60's Chrysler scoop design was to provide outside (cooler) air to the engine. Sealing the carbs to the hood plate is important to take advantage of this. Guys used to use longer vertical scoop support sleeves to bow the scoop up in the middle and had to remove them when other racers complained. Didn't seem to slow the car down any when they were changed to the proper length. Guys used to jack the back of the hood up (both to give the scoop a better angle of attack and to provide better underhood cooling) and the biggest noticeable difference was a bit better engine cooling in some applications. Once again, racer complaints made them align the hood better. The bent front license plate was an attempt to provide better air flow but I think it was really an attempt to make a shoebox (body style) more aerodynamic. I do remember the genuine Chrysler metal (both sheet metal and aluminum) scoops were always somewhat taller than any of the aftermarket offerings. The '68 hemi A bodies used a taller (about 4") top flared scoop that provided a measureable positive pressure inside the scoop that was not attainable in the earlier "B" bodies but that's not comparing apples to apples. My 2¢... BTW were there any SS/B or SS/C combos that weren't factory equipped with scoops? I don't remember any factory B body SS combos with a flat hood hemi. Last edited by Jim B; 08-16-2011 at 07:01 AM.

08-16-2011, 10:32 AM	#4
Phillip marvetz Senior Member Join Date: Oct 2008 Location: Lynden ,WA Posts: 820 Likes: 0 Liked 3 Times in 3 Posts	Re: '65 mopar hemi hood scoop The 64-65 scoops are different from the 67 scoops also, Although I have been told it is allowable to use the 67 scoop on a 64-65. [QUOTE "empirical" [/QUOTE] Nice word John, I'm going to use that one somehow today. How have you been? __________________ 2009 V/SA Record Holder Last edited by Phillip marvetz; 08-16-2011 at 10:39 AM.

08-16-2011, 03:55 PM	#5
GTX JOHN VIP Member Join Date: Jun 2009 Location: Boulder City, Nevada 89005 Posts: 2,538 Likes: 2,238 Liked 1,876 Times in 578 Posts	Re: '65 mopar hemi hood scoop My SS/CA Car was 68 Roadrunner with 426 Street Hemi with Rat Toaster Manifold......Back then the only Mopar that ran the class as weight could not be adjusted at all from shipping weight in the early days. Car was purchased from Mike Loge possibly when Chad was in Diapers. Phillip: I underwent another surgery about a month ago but I am healing well and all Cancer was successfully excised. I will be racing @ Vegas! Good Lord willing!

08-16-2011, 04:31 PM	#6
Dwight Southerland VIP Member Join Date: Dec 2001 Location: Arkansas - In the middle of everything. Posts: 1,981 Likes: 53 Liked 724 Times in 177 Posts	Re: '65 mopar hemi hood scoop What's the difference between a "Rat Toaster" manifold and a "Rat Roaster" manifold? One is crispy on the outside?

08-17-2011, 03:48 AM	#7
GTX JOHN VIP Member Join Date: Jun 2009 Location: Boulder City, Nevada 89005 Posts: 2,538 Likes: 2,238 Liked 1,876 Times in 578 Posts	Re: '65 mopar hemi hood scoop Pretty much is a question of how Well Done you prefer the Rats.........The Rat Toaster keeps them a bit more crispy on the outside and still squishy on the inside. I have a couple in the shop available for purchase of each......Manifolds that is as the Rats do not keep well after cooked. GTX John ( Lost Glasses in Lake Sunday and I am sorry for my proof reading )