Since I see the numerous threads that discuss this header vs that.... Show me your headers that were so cheap they came apart or performed POORLY here in this thread.

Make a compliation of DONT'S

 

While i can appreciate what you're trying to do, i don't think this is the right way to go about it.

Rather than promoting negativety and putting brands on blast for providing a low quality product. I think a more constructive way to go about achieving the same outcome is to promote quality brands and products. Giving low quality items and brands NO air time or advertisement is a better way to be. Plus i think this forum should be more positive, particularly in these current times.

I think there is enough posts and threads out there about cheap headers for people to make their own determination. Anyone who wants to spend $700 on chinese ebay headers wont be persuaded to spend ~$3k on MBH headers. Different horses for courses

 

I think that there are two categories of headers.
Headers for turbocharged cars and for aspirated cars.
In a turbocharged car, the quality of the welds is important because of a number of reasons.
1. The pressure factor
There is a pressure factor between the pressure formed in the turbine housing vs the pressure formed in the compressor housing.
Nobody measures it because you would need a pressure sensor capable to withstand high temperatures, but long story short, it's around 3. So if you see 25 PSI in the intake, the engine forms inside the turbine 75 psi. What holds the 75 PSi? The quality of the welds of the headers
2.The temperature
The flow restriction caused by the presence of the turbine causes more heat exchange between the exhaust gases and the headers. Heathers in turbo application don't run red, they run yellow hot.

So yes in a turbocharged application you will absolutely crack headers that aren't of the most expensive quality found.

But in an aspirated application, where in addition to the no back pressure, you removed the converters, what do the headers do?
The pressure across them is ... very small and the temperature accordingly doesn't increase much.

So then.... Someone asks.... How cheap can they be and still not break? They have very little to hurt them, comparatively speaking.

So yes, it's a valid question.

 

Install some $500 headers and the fitment alone will leave you knowing why they were so cheap. They wont seal, they will rattle, they will likely rub on your head shields. It's like comparing a press bent aluminized muffler shop pos job that rusts vs a nice mandrel bent stainless steel tig welded exhaust. Some cheap china rent a tire wheels vs tuv approved HRE's. They both get the job done, just one does it a lot better. Certain things are acceptable on a $70k+ car that aren't on a 16 yr old's honda ebay "race car".

Panzer said it best earlier. "Anyone who wants to spend $700 on chinese ebay headers wont be persuaded to spend ~$3k on MBH headers"
These are the same people that get upset with a few thousand dollar repair bill for their $65k engine. Sorry your oem factory race engine doesn't last forever on just oil changes.

 

The real problem that no one talks about with cheap headers/exhaust is really how they are made. When making exhaust lots of these cheap headers will use slip-fit connections and weld those. Slip fitting one pipe to another is fine if you clamp it. If you are going to weld it it would be a tight butt joint. You can see this in the headers or downpipes themselves. If the joint where a weld is is swedged out (bulged out) so one pipe can fit over the other then you know its a welded slip fit joint . Moisture from your exhaust can get trapped in that joint and lead to a crack or even rust. Then there is the welding process they use. Theor welding machine has a pulse setting. Meaning the welding torch beats like a hart and you can adjust this to whatever beats per second you want. This give the effect of "stacked dimes" Problem is with this is most Chinese headers do not use any filler rod. With filler rod you are melting new metal into the headers to make sure the joint is even and strong. Without using filler rod they are just surface fusing the welds. These welds are robbing base metal form each side sela up the joint making that area of the welded tube thinner that the rest of the tubing. Not to mention there is virtually no weld penetration. Then there are some import exhaust parts that will make 100 weld tacks in a row and call that a weld bead. These also have very little weld penetration. You can spot this by looking at the center of each weld "dime" there will be an indention from when the torch goes off. I could teach someone tomorrow how to weld like that and they could make cheap headers all day. To learn how to make quality TIG welds takes a lot of practice and time and skill. Those types of workers are not cheap. Hope this helps someone when it comes to understanding what is really going on with cheap headers. They are not just cheap because China makes more affordable stuff. They are cheap because whole build process is designed to cut corners and save money

 

I wouldn´t go that far and call our engines raceengines thou.
Yes high performance engines, but not race engines.
They have some issues every owner need to be aware of, fixing those and they are just as reliable as any other mercedes engine.

They only got ~82hp per litre displacement.
And a more reliable still not raceengine like a Honda K-series typeR engine has ~110hp per litre, they rev about ~8500rpm oem not having same issues as our engines.

And Vladds, having over 70psi backpressure in the turbinehousing, you got some serious problems, heat will kill the engine if ran long on those levels, although ~70psi isn´t that much pressure for a poorly welded pipe to hold.
Having that said, it is NOT recommended running those pressurelevels in the manifold, if not having the same amount of boost or more

 

I ran the boost in my Sti spec C engine at 24 PSI. The engine stayed with me between 60K miles and 150 K miles.
If you set your max boost at 24, there are no two ways about what the turbine pressure is, in order for the turbine to create the mechanical work that produces the 24 PSI in the compressor.

As far as "ran long". In a turbocharger, the max boost pressure it not reached all the time, not even many times. It is reached depending on engine load. The engine load is not at, or over the value that causes the maximum boost all the time. Even if this was a race car that spent all its life on a track, you won't see the boost gauge pegged to 24 throughout a race .... Not even half the time.
You can run a car in a race strictly inside an RPM range, a high range for instance. But you can't run a car inside a boost range, because the boost range is based on outside conditions. That's why antilag exists. And that's why antilagged engines have a prescibed number of hours of life between rebuilds.
However, you may be happy to know that Mercedes may have found a way to make non-destructive antilag. I believe the famous farts that the GLA45 does on upshifts are just this. The GLA doesn't come with a boost gauge, so an oltimer like me is busy looking for a matchine DEFI boost gauge. DEFi's are a beauty...

Sorry for the hijack, back to M156 headers...

 

So to further elaborate now
Which companies/vendors out there are buying headers made with cheap welds then branding them as their own

For example. How will I ever know HOW American Racing headers or MBH doesnt use the slip fit then weld them if I don't buy them and inspect (even though I know they don't)

Therefore I ask again: who are the headers to stay away from and why for each

 

Here is a video of one part of what i was talking about. This is called fuse tacking ats just Its a TIG welder set to a very low pulse setting just making repeated tack welds one after another. There is virtually no weld penetration and ZERO filler rod is used. The company is caller Mertop and they make total garbage. Sadly there are other companies that sell Mercedes only stuff that rebrands this garbage to sell to you. This is a huge part of the reason you can get downpipes and other exhaust stuff so cheap from China. Because its made so poorly.

 

I doubt any of them will fail. Even a half **** weld will hold the weak pressures of a na engine. Figment issues may exist for some but that has nothing to do with the weld or quality of the piping, just the wrong measurements between bends.

 

This is good info.
But again I want to hear from someone who had to send headers back bc of a bad weld, rattle, or poor fitment and I have yet to see that.

 

I have always been taught that headers are different than an exhaust manifold.

An exhaust manifold is used for a turbo charged car.
I'm specifically asking about headers for my NA and possible future SC application. There will be no turbo mounted to this.

 

These are the log type headers, such as https://www.ebay.ca/itm/372478235711...pid=8022262032 .
At the time I bought them, I think they were only $500ish CAD. Fitment wasn't an issue
Cracked along the welds. I had them repaired by a welder, and they noted that it wasn't purged properly. I've since gone with Becker/OBX long tubes, and the welds looked about the same.

 

This here is a stock exhaust manifold for the turbo application: Cast iron collectors, flanged in 3 pieces for factory packaging etc.




This here is a headers construction for the same application. Stainless, individual tubes, attention to individual exhaust streams and the merger point, packaging takes a back seat. Even in this world, there are several designs, this is known as unequal headers, there are equal lengths too.


My posting did not assume any turbocharging of a W204 C63.

 

So just so we're clear you realize they use the m159 in sls and amg gt GT3 race cars? The m159 is an intake manifold, dry-sump and set of camshafts (very mild change in profile because no need for low end torque and lacking variable length intake manifold in ours) away from a m156, + a set of restrictor plates for the GT3 cars to bring them down in hp to somewhere around 650hp. So yes it is a race engine - Literally. Also rumors of them lasting 15k + miles of RACING before re-freshening. High rpms don't justify a race engine. Cool at peak efficiency it makes more power per liter. Accomplishing that for 200rpm is very insignificant when everywhere else it is 50hp/L or less. I've driven gt3 porsches and S2000s as a perfect example and they are horribly slow to drive outside of 7000+ rpm. Id argue a porsche gt3 doesn't even feel like it makes 400hp much less the claimed 469hp and that's a 3.8L 6 cylinder doing 123hp:L . Ever experienced a 1000hp supra? makes over 333hp/L, the good news is even it makes that kind of power for 1500rpms the other 6000 are sub 200hp, would never consider it a race engine. Call it what you want. I say it's a racing engine with a few compromises to obtain a reliable, streetable, and emissions passing power plant.

As for headers - MBH you never mentioned the importance of back purging on stainless either, but I suppose we probably lost the $500 crowd after you talked about penetration! haha. . I've seen the insides of those trash china pipes. The inside either has zero penetration or looks worse than stick welds at an amusement park ride.

 

Good point. Another one of those practices the people who opt for cheap headers/exhaust miss out on. They need not worry though, there is no back side of the weld that need shielding since the is no meaningful penetration.

 

Its all about good penetration! I just realtized that you "mbh" are right down the 17 from me......A pm will be coming shortly sir!

 

You won't be disappointed, you don't want that rattle and crack.

Another note, the shop I went to have my MBH installed charged me way cheaper.

Compare to other shops charge me $200-300 more.

Fitment was easy for them to install.

 

i'm not a welder but i've had enough things welded, i'm no expert...this issue looks like use of wrong filler material and/or wrong heat setting or not bringing the base material up to temp before welding.

 

what shop did you use?

 

So......so far no one is saying that they have had any cheap headers fail at the welds? The manifold up above does not count!! Hmmm.

 

Post this question on the various C63 Facebook groups. Many of the younger kids who own C63's are using them and frankly i dont think they care. They seem to be holding up well, but i venture to say the ones that do fail dont come out and say it.

For me its as simple as piece of mind. its alot of work to fit new headers, i rather do it once the right way than have to do it again down the road.

Just FYI - I run Swain Tech coated Agency Power headers (which are the same off shore headers as FI etc.) and they have been holding up well for the past 7-8 years of owner ship. If i didnt get a steal on them back than, would I have paid full pop for them? nope i would have run MBH or ARH. But ehh they work just fine.

 

Exactly Kriston. If you want to put cheap shiitty headers on your Benz, nobody is stopping you. And guaranteed that you don't come back on here crying when they break at the flanges. Most people that don't care about workmanship and quality parts and materials probably wouldn't even know and would think the exhaust leak ticking is their lifters anyway.

This post seems like some sort of cry for attention to "prove" out whatever incorrect theory is taking up real estate in your head. They make a thing called the Google machine that will allow you to see hundreds of cheap broken headers online. Try using it.

Nobody cares, do whatever you want.

 

low cost high production cheap headers don't fail just sitting there. their welds fail when there is tension or blunt impact to the part. i.e. if your engine mount is busted and your engine has a lot of movement, your exhaust system is missing a flex pipe, or your exhaust hangers have too much movement.

the main concern is having welds bleed into the inner piping impeding perfect flow, generic low quality collectors, merge collectors not including center piece of metal like within a 4-1 collector, flanges not being welded on both sides, and just general build issues like crooked alignment and fitment issues.

none of these issues exist with a quality hand built manifold. cracking at welds can still occur with a hand built manifold if wrong heat range, missing back purge, inadequate filler material is used, or not preheating the base material.

 

For what its worth, I have Renntech shorty headers that I assume were quite expensive when purchased (previous owner had them installed) and they have a crack/leak on the passenger side. So its not only the cheap stuff that can fail. You run a risk with any purchase, some are riskier than others.