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Discussion Starter · #1 · (Edited)
Yesterday I finally took off my piece of junk manifold setup and started my first header.

I got a bunch of flanges cut on a water jet and I'm using 1.75" mild steel primaries.

I need to do a few things to clean it up like smooth out the ports then I'm going to paint it with some POR-20 then she'll be ready for service.

I would love to ceramic coat it but unfortunately the money situation isn't allowing that.

I'll put more pics up when it's done and mounted on the truck. You'll laugh if you see it next to my old manifold contraption.

Check it out:

 

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Impressive, MT, looks really good! Did you have tubes bent or buy preformed and cut off what you needed? Challenging project either way.
 

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Who needs mail order parts?????

For anybody that has ever tried to build there own headers/exaust, either on a gas or diesel motor will know how hard it is to get it right and make it look good! Nice job man.... have a beer on me..:beer:
 

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Discussion Starter · #4 ·
I'm pretty psyched on this one. I've built turbo kits for mustangs but this is my first try at a 4BT.

I just finished cleaning up all the ports with a die grinder now I'm going out to spray them with the POR-20 I bought a long time ago and never used.
 

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Where will this put the turbo?
I can see some definate flow improvement over stock here.
The stock manifolds like to shrink and crack, right?
Do you think a header will have the same problems?
Looks good!
 

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Just purchased 316-L S.S. to do same thing except on primaries using S.S. corrugated expansion joint tube(annular tubing). Takes pressure off exhaust manifold bolts. Also using 3" dia. 18" long corrugated flex off of collector with welded nipple ends to make totally water proof. Dont you think if you cut pieces between exhaust port flanges out might save future stud extractions? My 2c. Watched your Ranger buildup...Impressive
 

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Discussion Starter · #7 ·
I've never really seen a case where the turbo was mounted rigidly to the chassis as opposed to the engine. Seems like an unnecessary expense. I'd also like to see how those expansion joints can hold up to the temperature and pressure pre-turbo. On my mustang setups I use a flex joint in the middle of the crossover tube.

Stress on the bolts I'm using (3/8" grade 8) I can say is not in a dangerous zone without even doing any calculations. I would be more worried about fatigue of the welded filet joints at the flanges. If these become a concern I will make a brace that will be bolted to another part of the engine to take some load off.

I'm actually going out to install this badboy right now so I'll be back later.
 

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Sent you an E-mail of expansion joints. Would not mount to frame, roll of the motor would put unnecessary stress on joints, will mount on bracing directly to motor. These flex connectors withstand millions of cycles of vibration and lateral loads, check out site. Proved they're strength in HVAC, boiler and large diesel exhaust systems for decades. I use grade 8 also and have had to drill and extract more than a few from stock exhaust manifolds. Nice job on headers, can we see pics?
 

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out of curiosity what would you sell the flanges for assuming you have extras? If possible would love to call 'first,' LOL...
 

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Discussion Starter · #10 · (Edited)
Here are some pics of the final product and some of the original...






Overall I'm super pleased with this header over my previous setup. My EGTs lowered by about 100F and boost is up by almost 5 psi.

As for the flanges I have 14 more but all the bolt holes need to be enlarged and slotted towards the center of the port by about 1/8". I was going to get them all fixed up on a mill but if you want one as is you can have it for $35. If I get them fixed they will obviously be a little bit more for the machining fees.

FWIW I modified mine with an oxy-acetylene torch with no problems.
 

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Keep the flange and send me a complete header!:D
Looks good, and sounds like it works better!
I think you should come and practice some by working on my junk!;)
 

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Count Me In On A Engine Flange And Turbo Flange . This Is The Best Improvement I,ve Seen So Far On This Site . Could You Also Send The Part Number For The Air Filter You Got On Your Engine. I,LL DO THE EXTRA REQUIRED MACHINING .
Bob In Tn.
 

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Good work! How does it feel power wise? Is there a decent gain in the seat-o-pants dyno? Do you spool earlier?
 

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Discussion Starter · #14 ·
The boost comes on earlier it seems. I actually reduced in cab noise a little. If you look at my previous manifold junk it was kinda big and awkward. Less enthalpy into the turbo I assume. I was surprised by how I can't even get the EGTs to hit 1100 in 5th with the pedal on the floor.

Time for some injectors... hahaha

Overall I love the looks and the performance and I'll be making more sets in the future for sure. I'll buy one of those blue stars if I start actually selling a decent amount from this site.

Maybe I'll make a set from stainless when I can afford it. That would be sexy.

- Pete
 

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Looks like you are running a HE351 turbo. It has a larger comp. wheel than the he341/hy35. What kind of boost can you get out of it in the 1600-1800 rpm range?
 

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Looks great installed. I've gotta ask though, why didn't you weld the back side of the mounting flange to the head?

Did it stay flat enough after welding to seal okay?
 

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Discussion Starter · #17 ·
Seems pretty sealed to me. I welded it strategically to keep it from warping. I can't see any leaks. I use copper RTV instead of a gasket and never have problems with it.

Why didn't I weld the back side of the mounting flange to the head?

I'm not sure what you mean. I would never weld anything to the head of the engine if that's what you're saying. Also which mounting flange are you talking about?
 

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Why didn't I weld the back side of the mounting flange to the head?

I'm not sure what you mean. I would never weld anything to the head of the engine if that's what you're saying. Also which mounting flange are you talking about?
The flange where your headers bolt to the head. I notice you only welded the tubes on the engine side, not the back-side that you can see when they're installed.
 

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The exhaust port flanges where you put some tack welds
 

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Hey Mook...I love the effort. You probably already read this?

Hey all! I've been kinda lurking for a month or 2 now, getting ideas for 4bt conversion into a K5 Blazer that I hope to do someday (far into the future). Anyway, I noticed something about the 4bt manifold that I figured I'd bring to everyone’s attention.

Everybody knows that most turbos have a divided inlet to the exhaust housing. I can't remember the exact reason turbos are made this way, I think it has something to do with pulse tuning or something like that. Anyway, I do know for the divided exhaust housing to work the way it should, the pulses from the exhaust valves opening on different cylinders have to alternate between the two sides of the exhaust housing. So for example, on a 6bt, with firing order 1-5-3-6-2-4, the exhaust pulse from the number 1 cylinder goes to the front half of the turbo exhaust housing, the pulse from the number 5 goes to the back half, the number 3 pulse to the front half, alternating back and forth. This is why the 6bt exhaust manifold is designed so that the front 3 cylinders feed one half of the exhaust housing and the back 3 cylinders feed the other half.

However, with a 4bt things are a little different. The firing order for the 4bt is 1-3-4-2. Notice that instead of alternating between the front cylinders and the back cylinders like the 6bt, the 4bt alternates between the cylinders on the ends of the block and the ones in the middle. What this means is that the exhaust manifold must be designed differently to get the same pulse effect, and it is. If you look closely at the different factory 4bt exhaust manifolds, you'll notice that they're designed so that cylinders 1 and 4 feed one side of the turbo exhaust housing, while 2 and 3 feed the other, getting the desired pulse balancing into the turbo.

I bring this up because I notice many people are designing their own exhaust manifolds to fit the 4bt (often modifying a 6bt manifold) and coming up with manifolds that divide between the front and back cylinders. The effect of this is to send 2 pulses to one half of the turbo, then 2 to the other, instead of alternating pulses 1 for 1 between the 2 halves of the turbo. I don't know how much of a detrimental effect this has on turbo performance, but its something I thought I'd point out to everyone.


I see your header is configured 1-2/3-4 and you produced very good results (lower EGT's and greater boost) I wonder what the results would be if the header was plumbed 1-3/4-2? You may have hit on something like the Chevy "4-7" cam swap that changes the firing order on the SBC to gain better flow?
 
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