Header design in Grassroots Motorsports article....

[Careless]

i believe that I-6s are fine because there aren't 2 banks of cylinders.... or for some other reason that i'm not smart enough to know

 

well the entire reason for this is due to having exhaust pulses colliding with eachother in a regular "catch-all" collector setup, as I'll call it.

 

so since all the cylinders on an I6 are not firing at the same time, I figure 3 separate collectors would work the same here.

 

it would be a 120 degree exhaust, as each collection is 120 degrees out of phase in regards to the next one.

 

 

so tube 1 and 6 would be the first and longest pipes, tube 5 and 2 would be just short of that, and tube 3 and 4 would be the shortest, so that when the 3-4 firing has completed, all exhaust pulses arrive at the collector at the same time.

[proxlamus©]

sweet!

 

either single plane crank or the 180 headers!

 

Wonder how the bad boy sounds?!

[Scottie-GNZ]

Another option is Lou Gigliotti long-tube headers. Check out the pic and video. You can hear the sound pretty good in the video even over that god-awful music. :RANT: Why do people insist on putting loud music on car action videos? :RANT:

 

However, the video does not give the true sound justice. You have to attend a Speed World Challenge race to really appreciate it. If you want to see and hear 180* headers live, attend a TransAm race.

[BRAAP]

As was mentioned here and in that GRM article, the idea is for even exhaust pulses when those pulses meet up together in the collectors. Exhaust tuning can be more exacting that way, like on a 4 cylinder or the L-6. For a V-8, the 2 ways to do this is either a 180 degree crank, (aka flat crank, single plane crank, etc), or with the Dual plane crank V-8’s that we are accustomed to, (all domestic production V-8's), this can be accomplished by using “180 degree” headers as used on the Ford GT-40, some Panteras, or as fabricated on that Z in the GRM article. These tend be very long primary tubes and depending on available real-estate under the bonnet, can be quite ornate. The middle two cylinders of one bank pair up with the outer two cylinders of the opposing bank and vice versa. This makes for some very intricate header designs as seen in the accompanying pictures. The GRM claims of 40-50 ft lbs of torque, well, are not likely, though theoretically could be accurate, but only under certain circumstances and only with an engine built to a MUCH higher power level, aka Nascar. If he did engineer his primary lengths properly, took into account cam specs, induction properties, etc, realistically he may realize a 5-10 ft lb increase, 15 if he is lucky.

 

 

 

here are a couple articles with pictures touching on the 180 degree header design…

 

http://home.alltel.net/bsprowl/Exhaust/180FEHeaders.htm

 

http://www.ssheaders.com/header.htm

 

 

Here are some 180 degree V-8 headers for your viewing pleasure…

 

 

 

 

[Careless]

simply badass

[Careless]

Check out the pic and video.

[Scottie-GNZ]

Sorry. Another senior moment

 

http://www.lgmracing.com/lgm-0611-yearinreview.wmv

 

Right around the 1:10-on mark is where you hear it best.

[tube80z]

 

This pic reminds of me of Scott Charters Z. He ran a set of schoenfield headers turned around just like this and didn't really have the majority of the issues seen in the GRM article. The car was a definite beast.

 

Cary