anyone know a good exhaust fabrication in the bay area
03-09-2016, 11:40 AM
#16
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The primary tubes cross over before they get to this collectors. It has to do with balancing exhaust pulses on an V8
In a perfect world all V8 headers would be this design, but they are a nightmare to fit into a chassis
This is a Chevy V8 with conventional headers
This is an example in a 180 deg header in a Dragster
In a perfect world all V8 headers would be this design, but they are a nightmare to fit into a chassis
This is a Chevy V8 with conventional headers
This is an example in a 180 deg header in a Dragster
Is this only applicable to V8s or can other cylinder arrangements benefit from this?
03-09-2016, 08:30 PM
#18
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No - equal length headers address a different issue.
The 180 degree design really has more to do with the firing order than anything. Basically a conventional V8 has cylinder firings that are only separated by 90 deg of crank rotation. This means that the collector ends up with two pulses of exhaust going through it at basically the same time. This causes issues with backpressure, and messes with scavenging on the exhaust value (sort of a vacuum effect sucking spend exhaust gasses out of the cylinder) and some other crap you don't want to learn about.
By crossing the primary tubes over to opposing collectors it separates the exhaust pulses and solves a bunch of those issues.
It also sounds really cool.
Below is a Corvette with conventional 4-1 headers
and this is one with a 180 deg header
This same theory could apply to a V10 or V12, however most V10 & V12 applications use a different 180 degree "Flat Plane" crank design that addresses the firing order differently. The flat plane design basically uses the firing order than a 180 degree header emulates
Here's an interesting example
The Ford GT350 has a Flat Plane Crank
The Mustang GT has basically the same engine configuration - but with a conventional 90 deg crank
The 180 degree design really has more to do with the firing order than anything. Basically a conventional V8 has cylinder firings that are only separated by 90 deg of crank rotation. This means that the collector ends up with two pulses of exhaust going through it at basically the same time. This causes issues with backpressure, and messes with scavenging on the exhaust value (sort of a vacuum effect sucking spend exhaust gasses out of the cylinder) and some other crap you don't want to learn about.
By crossing the primary tubes over to opposing collectors it separates the exhaust pulses and solves a bunch of those issues.
It also sounds really cool.
Below is a Corvette with conventional 4-1 headers
and this is one with a 180 deg header
This same theory could apply to a V10 or V12, however most V10 & V12 applications use a different 180 degree "Flat Plane" crank design that addresses the firing order differently. The flat plane design basically uses the firing order than a 180 degree header emulates
Here's an interesting example
The Ford GT350 has a Flat Plane Crank
The Mustang GT has basically the same engine configuration - but with a conventional 90 deg crank
Last edited by Lowend; 03-09-2016 at 08:39 PM.
03-09-2016, 09:48 PM
#19
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OP - I'll also note... Lingenfelter does have a Flat Plane crank for the LSx
May be less expensive and painful to rebuild the bottom end than fit the bundle of snakes in a C5/6/7 chassis
May be less expensive and painful to rebuild the bottom end than fit the bundle of snakes in a C5/6/7 chassis
!
03-27-2016, 09:07 PM
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Here is one of my favorite examples of these style of headers - GT40:
GT40 w/ A/C: 2002 ERA GT | Bring a Trailer
GT40 w/ A/C: 2002 ERA GT | Bring a Trailer
03-27-2016, 09:51 PM
#22
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Here is one of my favorite examples of these style of headers - GT40:
GT40 w/ A/C: 2002 ERA GT | Bring a Trailer
GT40 w/ A/C: 2002 ERA GT | Bring a Trailer
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