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  #1  
Old 12-03-2010, 04:26 AM
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Twisted Minis Twisted Minis is offline
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Header

Truck came in for a header, decided to try my hand at building an equal length one. Three are identical in length, one is 1/2" longer. Best I could do. Equal length was not requested, so I didn't really fail, he just wanted a custom header. As of yesterday truck will be getting a full rebuild as well.







That is where I am today. Need to put a flange on it, then send it for thermal coating. Critique away, its my first one and I had fun. But I know there are some on here with more header experience, I noticed when I asked for info before. I would like to know what I can do better on the next one.
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Old 12-03-2010, 04:29 AM
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Cylinder 4 is the long one, BTW. In case anyone wondered. I could only imagine in my head 3 ways to route it. One was very short, one about 4 inches longer, and the one I picked was 1/2" longer and the most fun shape to do.
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Old 12-03-2010, 10:06 AM
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What is the primary and collector size. Looks like a 3/8" flange. Did you use tube or pipe. Bender and die specs, i am very interested on how you got that tight radius bend on the #6 and 8 cylinder. It looks very good and id like to try my hand at a set in the future. thanks.

Last edited by bluechev454; 12-03-2010 at 11:29 AM.
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Old 12-03-2010, 12:47 PM
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alwaysFlOoReD alwaysFlOoReD is online now
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That 4-1 looks good and should be better than stock, though the stock tri-y doesn't look bad.
I'm a hobbyist, and it's been 30+ years since I've looked into header design. And that was info gleaned from various hot rod mags. I'm wondering if the tubes with more bends should be designed slightly shorter? I guess you would need to know the rpm the engine would be working at the highest % of the time. And the speed of the gases and how much they slow down in a curve. Then make an educated guess. Maybe a flow bench would help?

Richard
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Old 12-03-2010, 12:59 PM
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Looks good! You can drive yourself nuts with the routing of pipes. Most of my stuff has been on open wheel cars, so there's a minimum of obstacles from the head to the collector, and it's still a PITA.

Someday, I want to do a set in stainless...
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Old 12-03-2010, 01:38 PM
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Ya the stock piece did not look bad, but his was damaged and beat up, didn't seal, and this is what he wanted. I had the parts on hand to build a 4-1, so thats what we did. Its not really a performance machine, its a 4 cylinder with some mild work. Maybe 120 horse. He wanted it more for the look, and to be louder than stock, I wanted to challenge myself.

The primaries are 1 5/8", that was the size of the stock port. The stock manifold was 1.46" though. The collector will exit at 2", that is the exhaust size we have decided to go with, since it doesn't put out too much power, and much bigger starts to sound tinny on these motors. Its a 3/8" flange, and I used 16 gauge tubing. I didn't bend any of it, I bought U-bends, and a couple of donuts to make all that work. The donuts are pretty cool. http://www.hrpworld.com/index.cfm?tp...action=product

Graham I was hoping you would reply, I have looked at your header projects a few times. Space wasn't all that bad on this truck, with a 4 cylinder and all the smog parts removed, I had a pretty good amount of room. I have a V8 for my project, so that one will be tricky. I had a lot of fun doing this though. I've always wanted to build a header, so I was really looking forward to this. I can't wait to do mine now. Just gotta build the frame first.
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Old 12-03-2010, 04:49 PM
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Wonder if a 4-2-1 design would've squeezed 3-4 more HP out of that 4-pot. Or retained some low-to-mid range torque at the very least...
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Old 12-03-2010, 10:01 PM
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What is the benefit to a tri-y type header? These motors make almost no torque as it is.
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Old 12-04-2010, 10:49 AM
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^ What he mentioned is the advantage. They help increase midrange power, fatten up the power band, whereas 4-1 tend to be better at WOT/higher range.
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Old 12-13-2010, 02:55 AM
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So the 3-bolt flanges came, so I finished the header.


Oh, Drew and Joe came by to help me make a big mess out of Chad's truck.

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Old 12-13-2010, 08:12 PM
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looks good, ive only made a few headers and nothing fancy, i know the the length of straight pipe section from the main flange to the first bend in each primary makes a big difference, if i remember correctly its longer for torque and shorter for hp,! so having two long and two short could make a difference, but i wouldn't imagine it being a whole lot on a 120hp motor. im not criticizing BTW, just some info, header looks well built and definitely an improvement over stock,
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  #12  
Old 12-13-2010, 11:07 PM
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I did not know that, thank you. I'm always open to criticism. Its the only way I will get better. I want to build some pretty wild headers for my own project, and I only want to do them once.
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  #13  
Old 12-30-2010, 10:57 PM
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Soooo, tore the other truck down and called the scrap guy again.

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  #14  
Old 12-31-2010, 12:54 AM
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The header is out getting ceramic coated. Supposed to be done and ready to ship next week. I'm excited to see it.



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Old 12-31-2010, 01:26 AM
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Do I spy some Avus wheels in the background?
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  #16  
Old 12-31-2010, 02:02 AM
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The last picture has some Audi wheels on the corner. They are off my S4 on a Mercedes race car that is getting some new chromoly sway bars and some after race repair.
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  #17  
Old 12-31-2010, 05:26 AM
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i need to get ma a chassis table. so handy.
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  #18  
Old 01-04-2011, 10:53 PM
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A little further along, but still much to do.

I pie cut and blended the top of the frame so that it would flow better, and then strapped the top. I wont forget shear load gussets, don't worry.

Transmission crossmember is in. You can see the start of a removable transmission mount in the first picture, and you can see the bolt hole reinforcements in this one.


And the header is back from ceramic coating.


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  #19  
Old 01-04-2011, 11:23 PM
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JaysinSpaceman JaysinSpaceman is offline
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Twisted,

That header came out sweet. And you frame is looking great too. Your work is getting really nice.

Thanx for posting
Jaysin
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  #20  
Old 01-05-2011, 12:41 AM
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Looks great. Where'd you have it coated?
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