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HEADER SIZE
#1233609
05/15/12 07:44 AM
05/15/12 07:44 AM
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Joined: Jan 2007
Posts: 90 North Carolina
CALSDART
OP
member
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OP
member
Joined: Jan 2007
Posts: 90
North Carolina
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I need some advice on the correct header size for an engine that has been dyno'd at 800 hp. Current headers on this engine are 2 inch. This is a drag car.
Last edited by CALSDART; 05/15/12 07:56 AM.
Calvin Thompson
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Re: HEADER SIZE
[Re: tubtar]
#1233613
05/15/12 04:01 PM
05/15/12 04:01 PM
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Joined: Jan 2003
Posts: 16,928 NC
440Jim
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 16,928
NC
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Quote:
This'll get you in the ball park.
http://www.wallaceracing.com/header_length.php
Interesting. I don't have any dyno data on my engine so I guessed 107% Volumetric effeciency:
4.250 stroke, 4.375 bore 90 BBDC exh valve opening at 0.020" adv, 320 adv duration Shift light is set to 6700 rpm.
6700 rpm, 107% VE Your Primary Tube Length is 35.47 Your Primary Tube Diameter is 2.06 inches Your Collector Diameter is 3.61 inches
7000 rpm, 107% VE Your Primary Tube Length is 33.79 Your Primary Tube Diameter is 2.11 inches Your Collector Diameter is 3.70 inches
I don't know if that calc is for OD or ID (guess ID). My headers are 2-1/8 OD and 0.060 wall, so that is 2.005" ID.
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Re: HEADER SIZE
[Re: MR_P_BODY]
#1233615
05/16/12 09:59 AM
05/16/12 09:59 AM
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Joined: Jan 2003
Posts: 16,928 NC
440Jim
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 16,928
NC
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Quote:
ALL tubing is OD
Yes, but all flow calculations are ID. The Wallace web site does not say if they adjusted the flow calc for an assumed wall thickness (0.030, 0.040, 0.050, 0.060, etc.)
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Re: HEADER SIZE
[Re: CALSDART]
#1233616
05/16/12 09:38 PM
05/16/12 09:38 PM
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Joined: Jun 2009
Posts: 644 Minnesota
Barnstorm
mopar
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mopar
Joined: Jun 2009
Posts: 644
Minnesota
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My 500in Indy 440-1 motor dynoed at 820hp 710tq and loved my 20 yr old Hooker Super Comps 2in staight 34length and 3 1/2 collector.
The little old lady from Pasadena is back!
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