Zod

As the title states what could the headers melting/twsited be caused by?
Am talking non stock headers here...

Peter_02AMG

Got any pictures?

Zod

Yes I do but, lets say I wana see it play out first.

Well any one, what can cause a header flange/collector to twist?
Stock cats and stock exhaust all the way back

jrcart

What kind of car are your talking about, engine? The reason I ask is that I have had headers melt on some of my race bikes, but that was 10 years ago and we ran carbs, long before fuel injection and the melted headers were a result of improper carb jetting. I'm not sure if if this is possble in a fuel injected car or not, I would assume the ECU would level out A/F mixtures or at least get them close. I would also assume if you were running that lean you would have some other internal damage as well...don't jump to any conclusions based on my post, I have very little knowledge on this topic, just thought I would share my "melted header" experience and what caused it.

jrcart

....one more thought, whenever you bend or form headers you are placing some inherant stress into the metal, when heat is applied it anneals (relieves stress) the metal and it can bend back slightly or even shrink out of it's desired shape. I am not an expert, but at some point the metal gets heat treated to avoid problems such as this. I suppose this could be a result of bad extruded tubing which was not formed or extruded at the proper temps.....

just another thought

Zod

on an AMG 55k car, and when i say twisted I mean like some one took a giant hand n just crushed it with his hands and just left it there crumpled in one area..

Havoc

Some sort of blockage like a faulty cat could cause that..

supre55

I have heard of shorties made of mild steel imploding because of the high gas temperatures (even with proper coating).

Rouven036

since the complete exhaust of your car is stock (of course the headers are not) there is no chance to twist that much how it happened on your car.
the catalytic converters are fixed with a small braket on the gearbox and also the conectors of the cats to the rest of the exhaust avoid a twisting. the brakets are not that strong and a little bit flexible but anyway there is no way to twist that much like it happened.
i came to this conclusion:
under high load/wot and rpm the header material gets weak and flexible, if you then lift of the accelerator, there will be (strength depends on the rpm range) a high vacuum pulsation who can cause this.
explanation: if the tb is closed and the engine is in coased load there will be (due to the valve overlap)also a vakuum pulsation in the exhaust system. this caused the collaps of the extrem hot header collectors.high rpm ranges increase the pulsation frequency and strength. also inherted stress on the material in production will have an influence on this.....
there was no problem on the injection system so far.

Rouven036

cats are not blocked, this is checked already, but i think jrcart (2nd post,inherted stress..) and supre55 hit the nail with their posts!!!!!!!!!

Rouven036

the collectors are looking like somebody exposed a pet bottle to a vacuum.

boohooramblers

Are the collectors collapsed to the point that significant back-pressure is created upstream? How are the exhaust valves, etc. holding up?

Rouven036

i think it is a combination of mild header material, high temperatures, inherted stress while building the header, vacuum and vacuum frequency.
how the condition of exh. valves, pistons etc is, we will see tomorrow. i hope that nothing happened to zods engine due to the increased back pressure caused by the collapsed collectors.

mkonei

if youre talking glowing orange tubes....overly retarded timing or a very lean condition will do that.


just reread youre post. they were mild steel if im reading correctly? did you have a thermal wrap on them?

Rouven036

af ratio is ok.

jangy

What are they coated in and how far back is coated? I've seen this with steel headers where the guys tried to "insulate" them with wraps. The heat stayed inside and basically cooked the headers.

Could this be a tuning issue? Not ECU tuning but header pressure tuning? The heat alone would only weaken it, especially if it wasn't properly heat cycled before. Something would have to cause the deformation.

What mods are on the car?Would a TB not help alleviate this by dropping pressure?

Rouven036

-headers (without any further isolation)
-stock exhaust system
-af ratio ok

its zods job, to state the mods (if he want to do so),but so far i can say the car was healthy untill this happened. again injection system, af ratio etc. is ok.

cls55

could it be a manufacturer defect.

jangy

You recone so? LOL!!

cls55

it happened befor and you were here.

Peter_02AMG

I wonder what the exhaust valves and piston head would look like if your headers are melted

jangy

My bad. I was attemting humor, since OP was obviously trying to let the data talk.

What do you mean that it happened before and I was here? I don't remeber anyone's headers melting

aleksandar1099

I can't remember one about headers melting, but I do recall someone having a problem with their evosport headers a while ago. Evosport took care of everything, great customer service...

jangy

Those were cracked headers which is more common. I haven't seen or heard melting. If EVOsport headers, wouldn't a seam give before the whole thing caved in?

AMS Performance

Without Pictures this thread isn't going to go anywhere. Show pics of the headers.