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Author
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Topic: Primary tube length
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Mpcoluv
Gearhead Posts: 928
From: Charlotte NC usa
Registered: Apr 2001
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posted 12-30-2001 10:54 AM
   
Just how bad are shorty headers?
A friend who has done a lot of Dyno testing has stated that secondary length (collectors) is more important than primary tube length. He thinks that in a street car ( where scavageing is nearly impossible with a full exhaust) shortys would not lose a ton of horsepower to long tubes if the secondary length is properly tuned.
Sanderson now makes a 1 7/8" shorty header for 351C 4V equipped mustangs. If I ever remove the super long (34" primaries) tubular automotive headers, I am considering shorties for ground clearence.
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kid vishus
Gearhead Posts: 4357
From: middle of NC
Registered: Oct 2000
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posted 12-30-2001 11:02 AM
I read an article that said the shorties killed power. Said it wasnt uncommon for there to be a 50 hp difference in a long tube header and a shorty header. Most poeple that run shorties, do so out of need (no room for anything else), not becouse they are better. Have you "banged" your headers on something now? My oil pan sits alot lower than my headers do, and I have smacked it a couple of times at the ractrack going from the grass to the blacktop pit lanes.
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Mpcoluv
Gearhead Posts: 928
From: Charlotte NC usa
Registered: Apr 2001
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posted 12-30-2001 06:44 PM
quote:
Originally posted by kid vishus:
Have you "banged" your headers on something now? My oil pan sits alot lower than my headers do, and I have smacked it a couple of times at the ractrack going from the grass to the blacktop pit lanes.
Any tall speed bump, or elevated driveway entrance. My car is lowered to a '69 - '70 trans-am mustang stance. Looks better, handles better, I just have to avoid things....
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Daniel Jones
Gearhead Posts: 489
From: St. Louis, MO
Registered: Aug 99
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posted 12-30-2001 09:50 PM
Jim,Did you read your friend's recent article on porting Windsor Jr. heads (nice article in a recent MM&FF). He stated shorties were decent on top end when running a full street exhaust but gave up a considerable amount of low and mid range to full length headers. How are your headers coming out of the port? It helps if you can get at least a couple inches of straight length before turning down. My swap headers for the 351C in the '66 turn down immediately. That's got to hurt flow. Dan Jones
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TomP
Gearhead Posts: 4780
From: Delta BC Canada
Registered: Dec 99
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posted 12-31-2001 12:55 AM
shorties would fall somewhere between a regular exhaust manifold and a "real" header. exactly where depends on the manifold and header and RPM range and things. The proper tuned length is never 10" so no application calls for a shorty. the street rodding crowd uses them because...well ,just because... like they use 350 Chevys in Mopars and Fords ...it's a monkey see- monkey do deal there. 34" is not really long... 48" is long! anything between 30" and 40" is normal.
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Butch Jennings
Gearhead Posts: 577
From: No. California
Registered: Apr 2000
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posted 12-31-2001 12:59 AM
quote:
Originally posted by TomP:
it's a monkey see- monkey do deal there.
Boy isn't that the truth!
------------------
Butch
460 powered 1967 Comet Cyclone
10.271 @ 130.069
Butcher's Home Page
"Friends don't let friends drive Chevys"
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Mpcoluv
Gearhead Posts: 928
From: Charlotte NC usa
Registered: Apr 2001
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posted 12-31-2001 09:47 AM
quote:
Originally posted by Daniel Jones:
Jim,Did you read your friend's recent article on porting Windsor Jr. heads (nice article in a recent MM&FF). He stated shorties were decent on top end when running a full street exhaust but gave up a considerable amount of low and mid range to full length headers. How are your headers coming out of the port? It helps if you can get at least a couple inches of straight length before turning down. My swap headers for the 351C in the '66 turn down immediately. That's got to hurt flow. Dan Jones
Dan,
Of course they turn down immediately. Mustangs demand that. He said that by playing with the crossovers (X-pipe) etc... much of the losses can be eliminated. This is assuming that you have the same back pressure with the shortys as with the long tubes. I think the real reason he thinks the shortys are not that bad is because scavenging is nearly impossible to achieve with a full exhaust.
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Mpcoluv
Gearhead Posts: 928
From: Charlotte NC usa
Registered: Apr 2001
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posted 12-31-2001 09:50 AM
quote:
Originally posted by TomP:
The proper tuned length is never 10" so no application calls for a shorty. the street rodding crowd uses them because...well ,just because... like they use 350 Chevys in Mopars and Fords ...it's a monkey see- monkey do deal there. 34" is not really long... 48" is long! anything between 30" and 40" is normal.
I never thought "Tuned Length" was important for an engine that operates over a wide range of RPM. Am I wrong here?
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Moneymaker
Administrator Posts: 19686
From: Lyons, IL, USA
Registered: May 99
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posted 12-31-2001 02:41 PM
Using Tony's Capri when it was a stoned stock street car as an example:
1)Stock FoMoCo headers with an "H" pipe and 2.5 "dumps" 14.40's at 94 MPH
2) SVO 1 5/8 SS shorty headers with same "H" pipe 14.20's. at 95 MPH
3)Hooker full length 1 5/8 super comps with custom 12 inch collector extensions 13.90's at 96 MPH.
Come to your own conclusions. I did. Shorty headers are for street rods or mild performance combos.  ------------------
Alex Denysenko
Co-Administrator and Moderator
NHRA/IHRA/SRA member
NHRA and IHRA SS/LA National Record Holder '00 & '01
Fleet of FoMoCo products
Moneymaker Bio
US Class Nationals link
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Daniel Jones
Gearhead Posts: 489
From: St. Louis, MO
Registered: Aug 99
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posted 01-01-2002 08:49 PM
> Of course they turn down immediately. Mustangs demand that. Even in your '69? I would have thought you have a bunch
more space than my '66. How I wish I had those Griggs mini
towers. I'd have a set of high ports in the '66 if I did. Dan Jones
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Money Maker
Administrator Posts: 63
From: Lyons IL, USA
Registered: Jan 2002
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posted 01-01-2002 09:42 PM
I still say that long tubes will ALWAYS out power shorties. ------------------
Co-Administrator and Moderator
NHRA, IHRA, and SRA member
NHRA and IHRA SS/LA National Record Holder
2000, 2001, and 2002
US Class Nationals co-organizer
Owner of a fleet of FoMoCo's including 88 ASC McLaren Mustang #28
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V8 Thumper
Gearhead Posts: 3366
From: Orange, Ca. United States of America
Registered: Dec 2001
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posted 01-01-2002 09:49 PM
Welcome to M&M 'Money Maker', great to have you aboard...(???)look carefully at 'number of posts' directly above... what gives?
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Dr. Who
Gearhead Posts: 164
From: Redwood City, Ca.
Registered: Sep 2001
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posted 01-01-2002 10:39 PM
Hey it's the "new improved" Alex! 
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V8 Thumper
Gearhead Posts: 3366
From: Orange, Ca. United States of America
Registered: Dec 2001
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posted 01-01-2002 10:42 PM
Alex, you were AWFULLY close to 10,000 posts... gotta start all over now! 
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Mpcoluv
Gearhead Posts: 928
From: Charlotte NC usa
Registered: Apr 2001
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posted 01-02-2002 07:18 AM
quote:
Originally posted by Daniel Jones:
> Of course they turn down immediately. Mustangs demand that. Even in your '69? I would have thought you have a bunch
more space than my '66. How I wish I had those Griggs mini
towers. I'd have a set of high ports in the '66 if I did. Dan Jones
It doesn't have a ton of room under the hood. More than a '65-66 though. The relatively tight engine compartment is why the cleveland's exhaust port makes that downward turn....
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Money Maker
Administrator Posts: 63
From: Lyons IL, USA
Registered: Jan 2002
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posted 01-02-2002 11:26 AM
New and improved????  There is nothing new here.  I didn't think that I needed any improvement. Did I? ------------------
Co-Administrator and Moderator
NHRA, IHRA, and SRA member
NHRA and IHRA SS/LA National Record Holder
2000, 2001, and 2002
US Class Nationals co-organizer
Owner of a fleet of FoMoCo's including 88 ASC McLaren Mustang #28
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iamblackjack
Gearhead Posts: 190
From: A small town in South East Texas.............Houston.
Registered: Jan 2002
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posted 01-03-2002 12:00 AM
I had some 1974 Aplliance headers on my car when I got it. The collector flange was 2 inches before the end of the trans. Talk about sweet sounding uncapped. They didn't drag much either, but they were so old and they started breaking at the first bends over and over. I replaced them with some Hookers long tube and they drag everything. 2 3/4" clearance to the ground. I would really like to know if there are tuned shorties for 65/66s.
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Money Maker
Administrator Posts: 63
From: Lyons IL, USA
Registered: Jan 2002
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posted 01-03-2002 01:15 AM
Appliance became BlackJack, which became Mr. Gasket, which became Cyclone, which became Walker Dynomax. I used to love the fit of Appiance headers. they were the first to offer individual flanges on each port. 4 bolt square collectors were kinda funky though. ------------------
Co-Administrator and Moderator
NHRA, IHRA, and SRA member
NHRA and IHRA SS/LA National Record Holder
2000, 2001, and 2002
US Class Nationals co-organizer
Owner of a fleet of FoMoCo's including 88 ASC McLaren Mustang #28
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iamblackjack
Gearhead Posts: 190
From: A small town in South East Texas.............Houston.
Registered: Jan 2002
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posted 01-03-2002 01:43 AM
Those 4 bolt collectors never leaked though. And the tubes on the driver side all went over the clutch equalizing arm. My push rod to the throw out arm commonly fell down and I can't fix it with these Hookers hot, but I could with the Appliance. Interesting history lesson, thanks.. 4 bolt square collectors were kinda funky though. [/B][/QUOTE] ------------------
Pair of '65s from Texas
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Money Maker
Administrator Posts: 63
From: Lyons IL, USA
Registered: Jan 2002
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posted 01-03-2002 11:10 AM
I wish that they still made the Appliance/Blackjack series. The fit and performance was good as was the quality and price. ------------------
Co-Administrator and Moderator
NHRA, IHRA, and SRA member
NHRA and IHRA SS/LA National Record Holder
2000, 2001, and 2002
US Class Nationals co-organizer
Owner of a fleet of FoMoCo's including 88 ASC McLaren Mustang #28
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