Welcome, Guest. Please login or register.
November 27, 2014, 01:31:46 am

Login with username, password and session length
Director PLEASE!!!!
Add your location information to your personal profile. Thanx!
415223 Posts in 35509 Topics by 8886 Members
Latest Member: seaslug
Search: Advanced search
Advertiser Inquiries
+ SBFTECH.com Experienced Small Block Ford Tech
|-+ Grass Roots Tech
| |-+ Grass Roots General Tech
| | |-+ Headers diameters and length formulas?
0 Members and 1 Guest are viewing this topic. « previous next »
Pages: [1] 2 Go Down Print
Author Topic: Headers diameters and length formulas?  (Read 3505 times)
teyerdhal
Small Block
***
Offline Offline

Posts: 185


Location: Paris (FRANCE)

« on: October 15, 2009, 12:40:57 pm »

I am pretty sure i found them one month ago on this forum but as for now, i fail...

Could you remind me the ideal velocity in the primary tubes?

Coud you remember me the math formulas for :

-Finding primary tubes O.D. regarding the CID and desired RPM and ideal velocity
-Finding primary tubes lenght regarding O.D CID and deisred RPM

Logged

68 FBK Mustang (Bullit like), 289, AFR 165 (1399) heads, unknown cam...,EDLK Performer RPM intake, QuickFuel SS-750-AN carb, E-Fire distributor with Mallory HI FIRE VI CDI box. JBA triY, teminator boxes and 2.5"exhaust line thru Dynomax VT mufflers.
T5Z, 9" 3.25 reard end.
347HO
A-1 Super Genious / Director of Maintenance
Section Moderator
Big Block
****
Offline Offline

Posts: 12195


Location: Seattle, Washington
I believe they landed on the moon.


« Reply #1 on: October 15, 2009, 01:05:02 pm »

Buy "Pipemax"

http://www.maxracesoftware.com/pipemax36xp2.htm
Logged




... it was REALLY revving at like 4K...
If I saw that thing in my rear view Im pulling over to let you by, I be scared of that thing Huh? i dont know wich car is uglier ur or mine?
Javier
Ugly?  Easy now -- that's my baby and it's got lots of unique character!  When I drop that built 445" stroker in it you won't have any time to "pull over to let me pass" because I'll have already blown past you when you figure out what the hell was that loud noise behind you . . .  
teyerdhal
Small Block
***
Offline Offline

Posts: 185


Location: Paris (FRANCE)

« Reply #2 on: October 15, 2009, 02:03:11 pm »

I need them for a debate on a french forum, so calculators are useless  Wink
Logged

68 FBK Mustang (Bullit like), 289, AFR 165 (1399) heads, unknown cam...,EDLK Performer RPM intake, QuickFuel SS-750-AN carb, E-Fire distributor with Mallory HI FIRE VI CDI box. JBA triY, teminator boxes and 2.5"exhaust line thru Dynomax VT mufflers.
T5Z, 9" 3.25 reard end.
347HO
A-1 Super Genious / Director of Maintenance
Section Moderator
Big Block
****
Offline Offline

Posts: 12195


Location: Seattle, Washington
I believe they landed on the moon.


« Reply #3 on: October 15, 2009, 02:43:09 pm »

In my experience, it's never good to enter a debate on an issue where you don't have experience??? Huh?
Stuff like that happens on this site all the time...   it's never good for the ill-informed, in-experienced.
Logged




... it was REALLY revving at like 4K...
If I saw that thing in my rear view Im pulling over to let you by, I be scared of that thing Huh? i dont know wich car is uglier ur or mine?
Javier
Ugly?  Easy now -- that's my baby and it's got lots of unique character!  When I drop that built 445" stroker in it you won't have any time to "pull over to let me pass" because I'll have already blown past you when you figure out what the hell was that loud noise behind you . . .  
teyerdhal
Small Block
***
Offline Offline

Posts: 185


Location: Paris (FRANCE)

« Reply #4 on: October 15, 2009, 07:12:15 pm »

In my experience, it's never good to enter a debate on an issue where you don't have experience??? Huh?
Stuff like that happens on this site all the time...   it's never good for the ill-informed, in-experienced.

I am sorry if i do not have formulas and numbers in memory, that do not make me in experienced.
I debate with people who believe in little diameter exhaust and shorties for sbf, backpressure for low end torque theory etc....
It seems to be i need some math formulas and examples to convice them about what happen really in headers, and what happen or not happen behind headers.

But if theses formulas suddenly became a secret, i will stay ill informed about them....

Logged

68 FBK Mustang (Bullit like), 289, AFR 165 (1399) heads, unknown cam...,EDLK Performer RPM intake, QuickFuel SS-750-AN carb, E-Fire distributor with Mallory HI FIRE VI CDI box. JBA triY, teminator boxes and 2.5"exhaust line thru Dynomax VT mufflers.
T5Z, 9" 3.25 reard end.
oldmanjoe
Adv_SBFTechie
Big Block
****
Offline Offline

Posts: 2667


Location: Tampa, Fl
ya `ll play nice ye-hear


« Reply #5 on: October 15, 2009, 07:57:21 pm »

http://www.n2performance.com/performance/exhaust-systems/index.htm
http://www.carcraft.com/techarticles/header_basics/size_objectives_conclusion.html
Logged

Still in the classroom hopefully still awake !!!
 A mind is like a parachute it ONLY works when it is OPEN
 Grandpa`s word`s of wisdom, joey that thing between your shoulders is not a hat rack
 Only a rich man can afford cheap parts, because he can afford to replace them
 If you did not understand what i said,say so and i will try and explain it another way
Many of life's failures are experienced by people who did not realize how close they were to success when they gave up.
Don`t get frustrated...get educated,you are at the library now ,so start reading .
Life`s journey is not to arrive at the grave Safely in a well preserved body,Rather to skid in sideways, out of control, totally worn out, Shouting Holy shit what a ride.
Inside the box is too crowded for me!!! besides every time you get going you run in to another corner.
 SPEED READING and written technical information , Don`t go together
Time is the best teacher, but most of its students die before learning the lessons.
IF YOUR READING COMPREHENSION IS NOT
OF A 5TH GRADE LEVEL DO NOT PROCEED {jay allen}
The voices in my head may not be real, but they have some good ideas!
289nate
"IL BUONO"
Global Moderator
Big Block
*****
Offline Offline

Posts: 10608


Location: Los Angeles

« Reply #6 on: October 16, 2009, 01:38:21 am »

Some reading in this link might help.  As far as an all encompassing ideal velocity in a primary tube...  

http://sbftech.com/index.php/topic,19160.0.html
Logged

\'65 fastback pump gas 289, 4.56 gears, and faceplated T5.  11.123 at 122.4
teyerdhal
Small Block
***
Offline Offline

Posts: 185


Location: Paris (FRANCE)

« Reply #7 on: October 16, 2009, 04:19:24 am »

Thanks for theses links (even if it is not the former link i was looking for,  dawn where did i see it!!)
It will be helpfull to open their eyes and minds...
Logged

68 FBK Mustang (Bullit like), 289, AFR 165 (1399) heads, unknown cam...,EDLK Performer RPM intake, QuickFuel SS-750-AN carb, E-Fire distributor with Mallory HI FIRE VI CDI box. JBA triY, teminator boxes and 2.5"exhaust line thru Dynomax VT mufflers.
T5Z, 9" 3.25 reard end.
Jay Allen
Camshaft Innovations
Banned Member
Big Block
*
Offline Offline

Posts: 5945


Location: SE Michigan

WWW
« Reply #8 on: October 16, 2009, 08:52:27 am »

I understand you are "discussing' this on another board, but here we need to dig deeper.

If I have an engine [cid is irrelevant] and I change the exhaust cam events, on a RUNNING engine you expect the exhaust "velocities" to act the same?

You think you need or want the same "velocity" on a 2.00" tube vs a 1.525" tube?

You think you want the same velocity on a 36" primary vs a 24" primary?

And how does the collector affect this?

There was a thread the other day in my section where guys wanted "examples" of "aggressive vs non aggressive" cam lobes.  I asked if I put that up would they know what they were looking at.  It was a YES or NO question.  The answer was NO.

OK, so you have a "formula" that was engineered about 30 years ago.  Does this mean you know what exhaust velocity is and how it affects a RUNNING engine with temps near 1400*?

I have several DOZEN calculators and I learn stuff about exhaust all of the time.  Discussing exhaust on an internet forum I have found is a waste of time.  Guys want to "dyno" the exhaust side of an engine.  I am here to tell you that is a 100% waste of time and energy.  Exhaust will affect acceleration and you may very lose 15 - 20 RWHP.

But run faster.

So.......

Calculators, Forums, Theories, and Dynos?  Hmmmmm

Results at the track?  

Next question.  Jay - Diet Pepsi
Logged

Jay Allen
CAMSHAFT INNOVATIONS

www.camshaftinnovations.com


Whatever It Takes !!!

UNTIL FURTHER NOTICE, ALL PM's ARE TURNED OFF.  I AM NOT IGNORING ANYONE, E-MAIL ME IF YOU NEED SOMETHING.
teyerdhal
Small Block
***
Offline Offline

Posts: 185


Location: Paris (FRANCE)

« Reply #9 on: October 16, 2009, 11:22:18 am »

Thanks for theses details, i understand what you are saying Jay.

I gave them real examples (stop light  and highway runs with my exhaust modified cars VS stock same cars or theorically faster cars). For now no one talk about Dynos (Dyno..ing engine is les common in France that in US) but it seem they need more "theorical talk" to be conviced 

I am not going to fight against windmills, if they want to stay on the statement "everybody says it so it must be true" il will give up and leave them happy with backpressure benefits.. Smiley
Logged

68 FBK Mustang (Bullit like), 289, AFR 165 (1399) heads, unknown cam...,EDLK Performer RPM intake, QuickFuel SS-750-AN carb, E-Fire distributor with Mallory HI FIRE VI CDI box. JBA triY, teminator boxes and 2.5"exhaust line thru Dynomax VT mufflers.
T5Z, 9" 3.25 reard end.
Joel5.0
El Hombre
Administrator
Big Block
*****
Offline Offline

Posts: 21595


Location: Puerto Rico
Miracles?.... by appointment only!


« Reply #10 on: October 16, 2009, 11:51:45 am »

I am not going to fight against windmills, if they want to stay on the statement "everybody says it so it must be true" il will give up and leave them happy with backpressure benefits.. Smiley

That is what you should focus on.

Backpressure: N; Residual pressure opposing the free flow of a gas or liquid, as in a pipe or an exhaust system.
Which can cause.......
Reversion: N; A turning away or in the opposite direction; a reversal.

Which one will make more power, be more efficient..........

THIS ONE:


OR THIS ONE:


IOW..... backpressure is simply a Don't ...no
Logged

ACRONYMS:
LUK  LMK  JIC  BTSTDTRT  YCYDYP  NFI-YTM  SPOBI, and the classic... DILLIGAS

'86 Mustang GT, X-303 cam, Holley DP 700, RG Tran., 289 Heads   Ford Smilie 2


Quote from: Joel5.0
The right to be stupid is inalienable for sure however, there is no such thing as a right to impose stupidity onto others
Great Thoughts will Overwhelm a Feeble Mind
There is never money to do it right, but there's always money to do it over.
Knowledge based on external evidence is unreliable.
He, who doesn't ask, does not deserve an answer.
A mind is like a parachute it only works when it is open.  (oldmanjoe)
If you can't explain it simply, you don't understand it well enough. (Albert Einstein)
Tuning on a Dyno for the track, is like swim practice in a bathtub.
I can explain it for you, but I can't understand it for you. (90lxcoupe)
The proof of understanding is the ability to explain it. (H. Torruella)
Ignorance is bliss, but stupidity is orgasmic.
Fraud and falsehood only dread examination. Truth invites it. (Samuel Johnson)
The chaotic resistance of the opponents leads to the conclusion that they are not prepared to meet the challenge. The problem is already much more psychological then technological. [Bojidar Djordjev]
Individuals are rational and humane... Crowds are reactionary and barbaric. (Jason)
The person who says it cannot be done should not interrupt the person doing it. –Chinese Proverb
Nothing sways the stupid more than arguments they can't understand - Cardinal de Retz
teyerdhal
Small Block
***
Offline Offline

Posts: 185


Location: Paris (FRANCE)

« Reply #11 on: October 16, 2009, 12:37:19 pm »

Yes i m agree with you and explained it, but backpressure benefits for low end torque is  the leading idea of their misunderstanding so it may be difficult to change their mind!


My real examples runs should help them, unless i am a liard..
I remember this old little car with just K&N filter, and bigger exhaust line with straightru muffler and 3Y header. It was so fun to blow 30-40HP+ same cars (sport models), seeing the face of their drivers was so good.


Now i am waiting for answers, i will tell you.. and stop arguing with this.

Logged

68 FBK Mustang (Bullit like), 289, AFR 165 (1399) heads, unknown cam...,EDLK Performer RPM intake, QuickFuel SS-750-AN carb, E-Fire distributor with Mallory HI FIRE VI CDI box. JBA triY, teminator boxes and 2.5"exhaust line thru Dynomax VT mufflers.
T5Z, 9" 3.25 reard end.
Jay Allen
Camshaft Innovations
Banned Member
Big Block
*
Offline Offline

Posts: 5945


Location: SE Michigan

WWW
« Reply #12 on: October 16, 2009, 02:04:40 pm »

but backpressure benefits for low end torque

This is wrong.

Back pressures slows the acceleration rate down and gives the SOTP Dyno the false image that you have more TQ.

Proof?

Go open header.

Most TQ possible.
Logged

Jay Allen
CAMSHAFT INNOVATIONS

www.camshaftinnovations.com


Whatever It Takes !!!

UNTIL FURTHER NOTICE, ALL PM's ARE TURNED OFF.  I AM NOT IGNORING ANYONE, E-MAIL ME IF YOU NEED SOMETHING.
Joel5.0
El Hombre
Administrator
Big Block
*****
Offline Offline

Posts: 21595


Location: Puerto Rico
Miracles?.... by appointment only!


« Reply #13 on: October 16, 2009, 02:25:25 pm »

What He Said........... as a 1982 classic goes..... "It's just an Illusion"... Naughty. When power across the board, but specially at the high end of the RPM range fails, the infamous "Torque Down Low" looks/feels to be improved....... by error or, caused by the driver's "Imagination".
Logged

ACRONYMS:
LUK  LMK  JIC  BTSTDTRT  YCYDYP  NFI-YTM  SPOBI, and the classic... DILLIGAS

'86 Mustang GT, X-303 cam, Holley DP 700, RG Tran., 289 Heads   Ford Smilie 2


Quote from: Joel5.0
The right to be stupid is inalienable for sure however, there is no such thing as a right to impose stupidity onto others
Great Thoughts will Overwhelm a Feeble Mind
There is never money to do it right, but there's always money to do it over.
Knowledge based on external evidence is unreliable.
He, who doesn't ask, does not deserve an answer.
A mind is like a parachute it only works when it is open.  (oldmanjoe)
If you can't explain it simply, you don't understand it well enough. (Albert Einstein)
Tuning on a Dyno for the track, is like swim practice in a bathtub.
I can explain it for you, but I can't understand it for you. (90lxcoupe)
The proof of understanding is the ability to explain it. (H. Torruella)
Ignorance is bliss, but stupidity is orgasmic.
Fraud and falsehood only dread examination. Truth invites it. (Samuel Johnson)
The chaotic resistance of the opponents leads to the conclusion that they are not prepared to meet the challenge. The problem is already much more psychological then technological. [Bojidar Djordjev]
Individuals are rational and humane... Crowds are reactionary and barbaric. (Jason)
The person who says it cannot be done should not interrupt the person doing it. –Chinese Proverb
Nothing sways the stupid more than arguments they can't understand - Cardinal de Retz
347HO
A-1 Super Genious / Director of Maintenance
Section Moderator
Big Block
****
Offline Offline

Posts: 12195


Location: Seattle, Washington
I believe they landed on the moon.


« Reply #14 on: October 16, 2009, 07:33:39 pm »

There's a thread here which concentrates on the Header Collector.
Jay flat-out told me, no bullshit...  that's where power and acceleration is made or lost...  more than the camshaft (which is damn inclusive and important).

I say forget the Header Tubes, and steer the discussion to the Collector!
Logged




... it was REALLY revving at like 4K...
If I saw that thing in my rear view Im pulling over to let you by, I be scared of that thing Huh? i dont know wich car is uglier ur or mine?
Javier
Ugly?  Easy now -- that's my baby and it's got lots of unique character!  When I drop that built 445" stroker in it you won't have any time to "pull over to let me pass" because I'll have already blown past you when you figure out what the hell was that loud noise behind you . . .  
Pages: [1] 2 Go Up Print 
« previous next »
Jump to:  



Powered by MySQL Powered by PHP Valid XHTML 1.0! Valid CSS!
Powered by SMF 1.1.18 | SMF © 2013, Simple Machines



408 Stroker