Northstar 180* headers.

[fieroguru]

The level of work required for 180 degree headers will keep them unique and not cookie cutter... which is worth it in my book but I am kinda nuts when it comes to fabrication.

Copper must have come way down since I purchased my mock up wire... it was over $100 at that time for the needed length, so I went with the much cheaper wire and PVC caps.

Where are some pics of the copper tube mock up... I want to see where all the tubes are going to be ran.

You really should tack all the tubes together and keep them loose in the collector until they all are completely tacked. Then you can take each tube and weld it fully. Once all the tubes are welded fully, put them back in the flanges and tack them back into place. Then weld up the inside of the tubes in the collector and then weld on the outside collector, then finish up welding the tubes to the header flanges. Welding them up like you are doing will make it very difficult to get fully welded seams on adjacent tubes and could lead to leaks.

For the tripod boot, one of the exhaust tubes on my 4.3 swap is within 1" or less of the passenger Tripod boot, so I cut out a small section of exhaust tubing an made a heat shield that was welded to the exhaust with about 1/8" between the exhaust an the shield. 15K miles and the tripod boot is still holding grease.

[Indy]

For my plastics Part Design class, my final project was plastic mandrel bends that snap together and allow you to exactly replicate the bend radius of off the shelf mandrels. If they were in production, I could save you a lot headaches by selling you a set, lol.

http://www.icengineworks.com/icewmain.htm

Their tacking clamps look like a brilliant idea that could be replicated cheaply.

[Aaron]

They better be worth it. I know they're going to look pretty boring under the hood, you'll only see 2 primaries. But the sound should be epic. Plus, as much as I bitch, I do love the fabrication.

Yah the copper was cheap, and it's easy to use too.

I thought about that, but I'll be able to get these without a problem. There's only 2 primaries that run together, and I'm going to install intermediate flanges on them, so the majority of the primary is completely removable and separate. However I've had that problem before, and always forget to think about it until it's too late, so thanks for the reminder!

For intermediate flanges, I'm going to go with standard TiAL 38mm flanges. They are thick at 3/8", so they won't bend, plus they are easy to find and cheap. Also they come with either SS or copper gaskets, so no fabric shit to deal with.

[Zac88GT1]

And if any of you are considering 180* headers on your N*, forget it. Unless it doubles the horsepower, it isn't worth it. I hate these fucking things already.

Haha. I know the feeling. When I started building the long tube set for my N* I had planned on making them 180* but after looking at it long and hard it was going to be extremely difficult to do with the lengths that i wanted. So i ditched the 180* idea and just tried to make them all as close in length as possible. Even that was a challange.

[Aaron]

I have another question, before I put up porn. I want opinions on X-pipes or H-pipes. For now the plan is a truel dual exhaust, however adding in an H-pipe would be really easy, and I'm sure I could figure out an X-pipe. However, I'm not sure if the advantages will hold up even on a 180* set of headers. Ideas?

So here is the impossible. Long tube, tuned equal length, 180* crossover headers on a Northstar 32v V8, all inside a Pontiac Fiero with the stock trunk. The two headers are in no way attached to each other, that's why it looks like the flanges are off. I've test fitted more than a few times, they work!

[fieroguru]

The 180 headers are all about the sound, so I would leave them independent...

The X's and H's are to help equalized the exhaust pulses between the two sides and lessen the impact of having unequal firing pulses on each side. With the 180 design, both sides already have equal firing pulses. They still might be worth a little hp, but you will lose the stereo effect from the exhaust tips with the alternating pulses from side to side equally spaced.

Now focus on making the collector back part equal length between the two sides!

[Aaron]

The 180 headers are all about the sound, so I would leave them independent...

The X's and H's are to help equalized the exhaust pulses between the two sides and lessen the impact of having unequal firing pulses on each side. With the 180 design, both sides already have equal firing pulses. They still might be worth a little hp, but you will lose the stereo effect from the exhaust tips with the alternating pulses from side to side equally spaced.

Now focus on making the collector back part equal length between the two sides!

Yah that makes perfect sense, they'll be left independent.

I'll try, but it's going to be near impossible now. But maybe....

[The Dark Side of Will]

180 degree collectors are NOT just about the sound. By spacing the exhaust pulses equally throughout the firing order, the ideal collector size gets smaller, and allows better power gains via correct collector sizing.

An X-pipe can bring about an impedance discontinuity that decouples that acoustic/resonant properties of the headers from the rest of the exhaust. With conventional headers, this results in a sound more like 180 degree headers, but the X-pipe should benefit a 180 degree design by lessening the amount of power that a quiet exhaust will cost.

[KurtAKX]

Stepped diameter?

[Unsafe At Any Speed]

When you guys going to be ready to fire up the car? I'll be down to Pike Peak International Raceway (PPIR) the 8th and 9th. It's just north of Pueblo.

[Aaron]

Stepped diameter?

No they are 1 5/8" the entire length.

When you guys going to be ready to fire up the car? I'll be down to Pike Peak International Raceway (PPIR) the 8th and 9th. It's just north of Pueblo.

We're still a ways off, still need to do fuel lines, water lines, wiring harness, vacuum lines, exhaust, clutch, etc. But I'll let you know when we are ready.

[Atilla the Fun]

And if any of you are considering 180* headers on your N*, forget it. Unless it doubles the horsepower, it isn't worth it. I hate these fucking things already.

Haha. I know the feeling. When I started building the long tube set for my N* I had planned on making them 180* but after looking at it long and hard it was going to be extremely difficult to do with the lengths that i wanted. So i ditched the 180* idea and just tried to make them all as close in length as possible. Even that was a challange.

equal length doesn't need to be within one inch, or even three, to give good results. If you can get them within 3, good enough.

[Aaron]

equal length doesn't need to be within one inch, or even three, to give good results. If you can get them within 3, good enough.

How many threads are you going to ruin with this bullshit? What's the point of having 180* headers if you are going to fuck up the primary lengths so bad that the whole purpose of the 180* headers is going to be discounted. 180* headers don't do shit if they aren't equal length, because you'll end up having 2 headers collect at the same, or nearly the same time anyways, and will again need the larger collector. Believe it or not, people haven't been spending countless hours making headers equal length for the past 40 years because close enough cuts it. Well yah, it does, when you want a header that gets exhaust from the head to the bumper. Some of us want a bit more than that.

[The Dark Side of Will]

When are you going to learn to chill out?

Why don't you calculate the difference in peak resonant tuning by varying header primary lengths by +/-1.5"? Why don't you calculate the difference in arrival times of pulses at the 180 degree collectors when primary lengths are varied by the same amount?

Quit talking out your ass and verify some of the things you spout off about.

[Atilla the Fun]

My verification was done by dyno testing, and never once, on a v8, have I seen a difference of 3" be more than 5 horses worse than truly equal, so the b.S. is yours, not mine. I've firsthand seen this testing on both a 380 horse 289, and a 925 horse 572. It holds true for everything in between. Even the best theory must bow down to dyno results.

[The Dark Side of Will]

Theory without experiment is a blind man painting a picture. Experiment without theory is a two year old with paint.

[Atilla the Fun]

maybe. In both of these cases, the headers started out truly equal, but had to be revised before final assembly, and both guys were concerned about losing the advantages of truly equal.

[crzyone]

I can't wait to hear this engine. Hurry up dammit!

[Aaron]

maybe. In both of these cases, the headers started out truly equal, but had to be revised before final assembly, and both guys were concerned about losing the advantages of truly equal.

So basically the design was flawed, which meant an inferior product. If they short-cutted that, I can imagine how poorly the rest of the headers are designed/built.

A 3" change changes the tuned RPM of that cylinder. I haven't yet been back to my calculator, but I know it changes it by more than 50rpm. This sounds great behind the computer, it'd produce a nice, wide power curve. The peak may not be as high, but the average will be really wide, much like that of the 4.9. Weird, everyone hates the 4.9. The problem is the rest of the engine is not made for that, and the lengths we're talking are probably only changing the tuned RPM by less than 1000. The average power over 1000rpm is not really important, unless you've got a pretty fucked up gearset. That, and the intake manifold is still equal length, the head is still the same for all 8, and the cams are the same. I'd imagine the results may provide a really nice driving engine, if you change every component with the header. But if you're not doing that, it's like putting a race cam in an otherwise stock iron duke.

[Atilla the Fun]

Again, theory must always bow down to reality. Your calculations and reasoning must bow down to dyno test results. As for your assumption of crappy header building, assuming just makes an ass of you. I'm not upset, and if you stop being an ass, I still consider you a friend.