just wondering what the reason might be as to why this manifold would crack after 4months of use?

crack in centre of collector



crack on 1st runner which has almost gone all the way around

 

O_o

interesting it cracked right down the middle of the weld....any cracks ouside of the welds?

 

thats what i thought.. no cracks on the outsides of the welds.

 

got any larger shots of the manifold and where the cracks are?

 

Flanges are warped i bet.

 

dont have a pic at hand at the moment, but the crack is on the centre of the collector between 2nd and 3rd runner. and the other crack is on runner furthest from cambelt.

 

Too much weight + vibration will cause that to happen. You can re weld it, but it will just crack again. You need to try and fabricate some extra supports for the manifold or for the turbo to keep the problem from re-occuring. I have this happen many times on a log manifold. I rewelded it probably half a dozen times or more. It even cracked right down the middle of the piping. So unless you try and prevent this from happening again, it will most likely get worse.

 

well it could be any number of things really...head flange not flat like psi2hi said, maybe the surfaces that were welded together werent flat causing stress, could have been welded poorly. or it could just be a crack. all those things happen. possibly that runner wasnt relieved of its stress relative to the head flange weld.

is the head flange cut to separate the runners?

 

well its not a cheap manifold (made by repuatable company on here) and its under gaurantee so will get it replaced im sure, but just dont want it to happen to the next one.. i personally think its the welding (dont look very beefy) and possibly the flanges.

 

this isnt necessarily true. ive built plenty of manifolds without any type of support, and have had no problems with them. if its a weight problem, i would suppose the crack would show in an area where the weight has the biggest leverage on the manifold, not the middle of the collector.

you can also fix cracks, and have them not come back again, as long as you do it correctly. obviously every situation is different...as is every method for building a manifold. im just sayin.

 

Centerline cracking has me leaning in the direction of a flaw in the center of the weld like lack of penetration, no backpurge, fisheye left in the center of the weld or perhaps a crappy tie in in the root pass etc and so on. Got any pics of the inside of the pipes?

 

It looks pulsed to me so i would have to guess lack of penitration. Seems like the guys who pulse have less of a bevel on there fit up. And you can't fill a gap that isn't there. So the weak weld would crack over the base metal.

just a guess on my part though

 

I would put my guess towards a faulty weld. Normally it's not the weld that cracks. It's usually the area around the toes of the welds.

 

heres a couple when i first got the manifold

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weight, heat, vibration, warping and not enough filler were most likely all the cause of this. my peakboost ramhorn had this same issue on one of the runners. seems like they didnt use enough filler. anywho, try to get whoever the maker is to warranty it. goodluck.

if you dont mind asking, who was the fabricator?

 

It is obviously a stress fracture in the piping and/or the weld, which is due to weight and vibration. Seen this many times. You just re weld it, especially with small welds like what are on there now, it will crack again.

 

Just PM the company on here they seem like a good bunch I'm sure they will help you out.

 

Something not well known, though potentially related to this issue is "amperage pulse welding" or "pulsing" as it is called is really bad for stainless steel and pressure vessel work. There is a very tiny flaw cause when the amperage suddenly drops called a "hot short crack". There is a hot short crack in each crater of that cracked weld.

I know many of you have welded dozens of manifolds and had no failures and I am sure this is an isolated incident, the work is beautiful but lacks penetration.

I worked as a pressure vessel fabricator for a few years, We made devices for oxygen service that operated at very high pressures and temps. Washing, pulsing and cup walking were typical causes of failures. Those techniques are usually used in sanitary welding for food service with lower temperature and pressure requirements. Some dye testing could show other potential issues.

 

Low-speed pulsing has shown to have various effects, but high-speed pulsing has shown to be virtually free of hot short cracking. At 1000PPS and above, there is not sufficient time for this to occur.
Pulse settings are usually not thought about very much, and this is a main cause of problems. If you are going to use pulse, you have to crank the amps, and decrease the time spent on the peak. Ohterwise, there is no benefit in terms of heat input compared to regular DC. It just ends up cold. As a rule, keeping background amps above 25% will eliminate alot of the problems also.
If you look inside the collector pic, there are some fairly serious issues.
Lack of proper gas coverage in areas has led to complete oxidiation. There is also some very serious misalignment or high-low. Then, on the lower right port inside the collector, there looks to be a bit of porosity.
The welding on the outside looks decent, so fitment looks to be the main culprit.

 

have done already.. still waiting for a reply.

and the worse thing is im suppose to be taking the car around the nurburgring in december so i need it replaced in time, and im in the u.k if you was wondering

 

Good luck on having it repaired.
But Nürburgring with a Ramhorn, which usually means half size radiator, isn´t a good thing in my oppinion...

 

**** ramhorn with stock dx half size single core works fine for me. **** ive never seen any temps over 205.

 

The ring in December. Brave man.

 

Yep just as I suspected. Personally I would send the entire thing back and make them send me one with purged full pen welds but that's just me. So many people on here are worried about what color their welds are but ignore things like backpurging and full penetration. It's just silly.

 

i know wont be pushing it too hard though no doubt nice and wet! going there to stay with a friend but he lives right next to the ring, never been in the wet though..

oh and the civic rad was good on a pals civic turbo around the ring so should be ok, but like said it will prob be wet so not ganna push it hard.