this is good?



1-3-2-4 and 7-6-5-8 in sequence

with an X pipe the 2 banks should sequence the same rotation or would opposite be better?

"You boys better hold on to somethin, I'm gonna hafta stand on it" ~ Dad Seegle

With a 4 into 1 header it makes little to know difference. Tri-wyes do

Mark McKeown
McKeown Motorsport Engineering, Inc.
http://mmeracing.com
http://racecrateengines.com

looking at an isolated bank tri-Y i'm seeing an arrangement like this to minimize the consecutive pulse on each bank



crossing the 2,3,6 and 7 could create a true steady side to side even pulse but is likely not possible in any production chassis?

"You boys better hold on to somethin, I'm gonna hafta stand on it" ~ Dad Seegle

A friend of mine picked up an old NHRA sbc Pro Stock truck motor that came with Tri-y's. Don't really know if they help/hurt but the engine does sound kinda funny though. But part of the sound might also be because it also has 4 cylinders with a firing order/cam swap.

what is that? and why is it better? and how much better?

basically when 2 cylinders on the same bank fire consecutively the collector gets overloaded and pressurizes. the second cylinder to fire consecutively suffers. in regards to our Clevelands this happens right off the start of the firing order with 1&3, then 7&2 are OK being on opposite banks and it happens again with 6&5, then 4&8 are OK and it happens again...

the concept is to break up the consecutive hits. if you cross the 2&3, 6&7 tubes to the opposite side collectors you'll have the problem licked
http://www.gpma.org/Archive/gt40s.html
notice that the collectors are not much larger in diameter than the primary tubes, they don't have to be because the flow through them is perfectly even. they're not getting overloaded off and on, they're just extensions of the primaries

Tri-Y's do the best they can to separate the consecutive cylinders without crossing tubes side to side. the 1&3 primary tubes feed into different secondary tubes, but pair up with the cylinder that is opposite in the firing order. the 6&5 are also separated and paired with opposite cylinders

http://www.stans-headers.com/tri_y.htm

http://www.superchevy.com/technical/engines_drivetrain/exhaust/0504sc_header/index1.html

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

the poorman's high-end custom header is the H crossover tube or X pipe


"You boys better hold on 'cause I'm
gonhafta stand on it" ~ Dad Seegle









"You boys better hold on 'cause I'm gonhafta stand on it" ~ Dad Seegle

Thats what we had back on our old late model stock car, 357C 12:1 the 180's over the top headers buzzing @8K was a sound to behold.

here's a pic like the ones we used






http://www.fordmuscle.com/forums/garage/486839-180-degree-headers.html


All Right You Sons-a-Bitches, Let's Have a Race! Smokey Yunick

(I have more pics at home, this is the only one I have in photobucket, a lot of Pantera owners opt for an exhaust system like this)

-G
__________________________________________________

tubes are crossing side to side?

"You boys better hold on 'cause I'm gonhafta stand on it" ~ Dad Seegle

off the top of my head I believe its the middle cylinders on both sides, 2 & 3 and 6 & 7. Look at the firing order & it should make sense.

-G

that's what i came up with, it's just hard to see through the jumble, looks like it could be only 2 crossing but i couldn't come up with a 180 design that'd work only crossing 2. why i'm playing around with it i have no idea, likely i'll be looking at Hedman 85230?



"You boys better hold on 'cause I'm gonhafta stand on it" ~ Dad Seegle

Ignoring the fact that's a non-Ford in the engine bay, focusing on the exhaust.
You should hear this one, it screams like a formula one car.



-G

i'd think that'd be one confused collector, is it rotational(would be some feat) or anything special going on inside?

"You boys better hold on 'cause I'm gonhafta stand on it" ~ Dad Seegle

I read on Speedtalk that this truck has a 8-1 system. They said it was tough, but worked really well. Sounds wicked to boot!

http://www.youtube.com/watch?v=OxQAz_tJuWw

Tin,

You'll notice the order in this one differs from the first picture, they are built for two different motors, the first one was a BBC, these headers are built for a Clevo. Yes the builders of the 8 into 1 systems seem to put them into some sort of order, but I have never had it explained to me what the criteria is.

The 180 degree systems sound smoother than a typical exhaust, but they still have that low frequency "cross plane crankshaft" V8 rumble. The 8 into 1 systems loose the rumble altogether, they have that Formula 1 or Ferrari whine, like they have a "flat plane" crankshaft.

The 180 headers are supposed to be worth 15 to 30 horsepower in an unmuffled race engine compared to a standard set of headers. I've never heard how much gain (if any) the 8 into 1 systems provide.



-G

You can hear these Pantera's have 180 degree headers.
http://www.youtube.com/watch?v=_zdMEWr34tk

71 M code Mach 1, Tremec TKO, Wilwood SL6's, road racer.