Northstar 180* headers.

[THE PUNISHER]

ahhhhh

who's welding this up?

Globby Mig Welded headers FTL!!

have someone tig it..... do the right thing.

[Aaron]

If you want to pay for it, or buy me a TIG, I'll be more than happy. But $40 for the argon is tough to beat, so I'll be doing the welding.

Don't talk shit until you can do better. So let's see your headers.

[THE PUNISHER]

I typically have them made.. headers are an exact science..ask Will about that. The manifold on the Civic was done by Eville, and I have another by Jay Thorton. Nothing says failboat like globby ass mig welds...

Could I do it? For sure, I have the tools, I am a better welder then you, so I think thats a safe bet.

Funny.. Don't see you post much on HMT or RHMT anymore... perhaps due tot he fact you got laughed off?

Good luck.

[whipped]

I bought a TIG from HF for $250 + 100 bottle +30 reg... It's not bad. You could hack a foot pedal into it and be golden. No high freq start, so it's tap start, but still better than anything else I've used.

[The Dark Side of Will]

This is Tech, not VTW.

[Nashco]

I've got a TIG and a MIG. I just made an intake (yet to be tested) for an old Volvo that I'm megasquirting. I could have saved BOATLOADS of time doing things differently rather than making my own manifold, but I wanted to give fabbing a manifold a shot as I never have, and this one was pretty simple so I thought it'd be a fun experiment. I made it with all scrap I had around and $40 worth of steel mandrel bends. I MIG'd it, and I'm glad I did. Sure, it's not as pretty, but even with the MIG and a four cylinder intake it took a long time. TIG would have taken a hell of a lot more time on this little manifold, with a huge ass set of V8 headers it'd be days worth of welding for me to TIG it and even a really good welder would still need at least a day. I can't blame anybody for making some uglier MIG welds instead of TIG, time is money and unless you're getting paid by the hour or building a show car, I just don't see the sense in it. I can MIG a mocked up part about four times faster than TIG.

Obviously, I'm talking decent MIG vs decent TIG. No type/brand of welder is going to make a bad weld not bad.

Bryce

[Aaron]

I typically have them made.. headers are an exact science..ask Will about that. The manifold on the Civic was done by Eville, and I have another by Jay Thorton. Nothing says failboat like globby ass mig welds...

Could I do it? For sure, I have the tools, I am a better welder then you, so I think thats a safe bet.

Funny.. Don't see you post much on HMT or RHMT anymore... perhaps due tot he fact you got laughed off?

Good luck.

Every dimension that is an exact science, is something I can achieve. If the optimal primary dimensions for my black car are 1.75 X 20 X 2.5, then I'm spot on. Sure the welds may not be up to some of your high standards, but who are you to set standards you yourself can't (Or at the very least haven't) hit? Do better, then talk shit. I can buy nice stuff, anyone can. But doing it yourself is a far greater accomplishment. When it came to the intake welding on my build? I paid for it. Yah, it looked damn good. That's the only thing it does better than my welds.

WTF are you smoking? I've got a fucking thread on the N* Fiero on HMT. Nothing but good things to say so far, and that includes my "globby ass mig" welded cradle.

I bought a TIG from HF for $250 + 100 bottle +30 reg... It's not bad. You could hack a foot pedal into it and be golden. No high freq start, so it's tap start, but still better than anything else I've used.

When I do buy a TIG, it's going to cost more than my car. I don't want to have shitty welds, and not know if it's me or the machine. I want to be positive it's me.

Will, will you edit already? That's why I put this thread here. I put the car's build thread in NT, because I'm ok with the bickering. But don't delete, edit. Thanks

[The Dark Side of Will]

I haven't edited anything here... just reminding you troublemakers that this is NOT VTW. Even if you're OK with bickering, I'm not.

[Aaron]

You missed it, I want you to edit this. That's why I put this thread in tech.

[fieroguru]

I wouldn't mess with tig unless they are stainless. Mine will be mig'd since they are mild steel and that is what I am setup to weld at this point. I will smooth out my welds to make them look nice before sending them off for coating.

Once you are happy with them, build a set in stainless and use a tig... sould be the last time you ever need to mess with them.

[Aaron]

Alright, I'll have a pretty nice update, with pics, here in a few hours. I used A. Graham Bell's book "4-Stroke Performance Tuning" to get another set of primary dimensions for these headers.

Exhaust valves open 51* before BDC
571.5 is the cylinder volume in cc
You want to tune at the peak torque rpm for a street engine, which is 4500 on the LD8 N* (275hp variant)

Using his formulas, I get a primary length of 41", and an ID of 1.51". This works out perfect, since I ordered 1 5/8" tubing, and the ID of that is 1.5625", which is very close. Also, I placed the collectors based on a 36"-42" primary length, and 41 is at the top end of that, which gives me a lot of room to place them where I want. Pics soon, along with the next step in DIY header building.

[darkhorizon]

I wouldn't mess with tig unless they are stainless. Mine will be mig'd since they are mild steel and that is what I am setup to weld at this point. I will smooth out my welds to make them look nice before sending them off for coating.

Once you are happy with them, build a set in stainless and use a tig... sould be the last time you ever need to mess with them.

I mig'ed with stainless because it was harder for me personally to use the tig on the stainless. I usually use the tig for mild steel welding, and my fluxcore mig to mock things up, or do exhaust work.

[The Dark Side of Will]

You want to tune at the peak torque rpm for a street engine, which is 4500 on the LD8 N* (275hp variant)

What year engine are you working with?

Flat tappet engines:
LD8: 275 HP @ 5200 RPM, 300 ftlbs @ 4000 RPM
L37: 300 HP @ 6000 RPM, 295 ftlbs @ 4500 RPM

[Aaron]

What year engine are you working with?

Flat tappet engines:
LD8: 275 HP @ 5200 RPM, 300 ftlbs @ 4000 RPM
L37: 300 HP @ 6000 RPM, 295 ftlbs @ 4500 RPM

Fuck, I read that wrong. I was reading the L37 torque. Oh well, it won't make that much of a difference, just bias the power curve a bit more on the top end. I'm not sure of the year, but chances are, it's an earlier one. Maybe in the future we'll put the L37 cams in too.

Materials came in:




Once you have your materials, the next step is to place the collectors where you want them. Be very careful doing this, as they need to clear everything, the primary tubes need to reach the collector in the desired length, you need to have room for the tubes into them, room for the downpipes, room for the V-bands, and they need to removable. So spend a lot of time on this step. Unfortunately with 180* V8 headers, I can't put the collectors anywhere I feel like it, in fact it's extremely difficult to get them where everything above is satisfied. Here's what I'm going with for now:





Next is to form the primary. There are a few ways of doing this, here's mine. Go to Home Depot, and buy 1/4" copper tubing. It's sold in 10 and 20 foot rolls, I needed 30'. It was like $20. Next, cut the tubing into your primary lengths, so I cut 8 pieces at 41" each. The copper tubing is nice because it's easy to bend, will hold it's shape once bent, and no matter how much you bend it, it will always be 41" long. Now form the primary tubes. This takes some practice. Every bend you make needs to be in the radius of the tubes you bought. This isn't very hard to do, you should have to be cognizant that you can't make a bend too sharp. Also be aware that the copper tubing is 1/4", not 1 5/8". For me I can visualize a 1 5/8" tube, so clearing everything isn't too difficult. But if you want to be extra careful, Home Depot sells insulation for tubing, very similar to the testicle protectors on kid's bikes. It fits around the tubing, and can be found in diameters similar to our pipe size. It's also cheap.


Here is how the headers are looking so far. I'll add now, this is a royal pain in the ass. This is leaps and bounds ahead of my Fiero headers in terms of difficulty. I'll be shocked if I'm able to make these work, with an exhaust system I like. I'm also going to need to add flanges midway down at least half of my primary tubes, probably all. This is the lower header, which is merging cylinders 2, 3, 5, and 8. Only one of the four primaries is significantly completed, and I spent the past 7 or so hours on this.

[Jinxmutt]

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.

[whipped]

I'm not sure of the year, but chances are, it's an earlier one.

Check for 2 digit year starburst stamp on the heads. Also the water crossover.

[The Dark Side of Will]

Looks like you're going to melt a CV joint boot. Might want to look into an intermediate shaft.

[The Dark Side of Will]

What year engine are you working with?

Flat tappet engines:
LD8: 275 HP @ 5200 RPM, 300 ftlbs @ 4000 RPM
L37: 300 HP @ 6000 RPM, 295 ftlbs @ 4500 RPM

Fuck, I read that wrong. I was reading the L37 torque. Oh well, it won't make that much of a difference, just bias the power curve a bit more on the top end. I'm not sure of the year, but chances are, it's an earlier one. Maybe in the future we'll put the L37 cams in too.

If you're going to the trouble of being "ideal"...
It's a lot easier to change the design BEFORE you start cutting pipe.

[Aaron]

At this point, it's after, as that primary is all but complete. However I'll be adding about an inch in length to all of them because of the intermediate flanges, so 42". Might be good for a hundred or so RPM. The 41 would be ideal for a L37 engine, so if we ever do upgrade (Which we've talked about), the headers will be even better suited. They will still be tuned and perform very well, just make the LD8 a bit more top end happy, which is a good thing. It won't really cost any power, just may cost a little torque in the midrange. But it will help maximize the efficiency if we ever cam it.

So far, it looks like I'm going to need intermediate flanges for cylinders 2 and 8 on the lower set, the front plugs 3 and 5 should be able to drop down no problem. And I should, once I've disconnected the front two, be able to drop that header out without removing anything else.

[Aaron]

Looks like you're going to melt a CV joint boot. Might want to look into an intermediate shaft.

It's actually farther away than it looks, and with the airflow underneath the car, I think it'll be ok. I'll wrap that portion of the header just in case though. Thanks for the input!

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.