dester223

I have a friend whom owns a decently priced header and this is his SECOND header from these guys. They keep cracking @ the welds.

This is a picture of one that is cracked all the way through. No bashing of the company needed so no need for the name of the header.

I'm no welding expert, but I am almost 100% positive that it's Tig welded, but to me the weld looks more like a fusion weld. It looks VERY thin. Examining the crack in the other spots where it hasn't broken through yet, the crack forms where it looks like they pull the torch away and then the crack runs down the center of the weld.

Really looking to see if there is a problem. There's a flex that is welded in the exhaust, but I will not post pictures of that, because it will be really easy to identify the header that way. There are multiple spots where the header is cracked and one piece looks like with a little tugging, it's ready to just fall out and have a section missing.

ManBearPig4silly

It is tig welded. Fusion welding is just tig welding without filler, which they may have done. It's hard to tell from that pic.

Sounds like they didnt end the weld properly. The little "fisheye" where you said the crack started should be done away with by adding filler while letting off the amps as well as rolling it off to the side of the weld instead of leaving it in the centerline like it sounds they did. Other than that I would suspect lack of penetration along the entire length of the weld resulting in that incredibly straight crack. Long story short it just wasnt welded properly.

Good news though. It can be fixed! Make sure whoever fixes it cleans all the carbon from the inside of the tubes, back purges and uses filler.

atutt

That crack is to clean to be anything other than zero penetration.

I hope this is a case where someone had a brain fart and forgot to do something. i hope the rest of the manifold isn't built like a wet paper bag.

VtecFreePrelude

fusion is the joining of two metals to become one. all welding has fusion. autogenous welding is using gtaw without filler. it leaves a concave face and actually fuses decently. it looks like that weld you posted had no penetration or fusion due to the split right where the pipe ended.
as for the reasoning, the fisheye is actually more than likely the culprit although the crack is amazingly straight for a failed "quality" weld... obviously its not a good weld

9bells

There is no prep there either. Must have been a mistake.
I really want to know how long this lasted, because it should have only been 1 heat cycle, but I bet it lasted a little while based on the colour and overall appearance of the manifold.
I have never seen a crack that straight before....

SlowReaction

Do you have some pictures of the whole header?

91jdmhatchback

just go google "bisimoto header" if you want pictures of what it looks like.

extralargenog

iTrader: (1)

wierd...

Looks like filler added everywhere else, hard to tell on that runner... REALLY looks like a fuse weld, but then theres like 1 little spot that looks like it was touched with filler... IDK, if itsw already been fixed asnd failed again, find someone local that actually knows how to weld and have them fix it.

Youd probably have better odds judging from what you say.

Id be pissed.... I know its not a cheap piece....

Vagitarian

Never seena crack straight and perfect like that before

Cant blame the company (or I suppose you can if you wanna get technical), thats just a poor weld

91jdmhatchback

LOL wut?

Vagitarian

Company designed a perfect header, there welder, whether inhouse or sourced out just didnt weld it properly

9bells

If this is really true, alot of the headers I found were autogenous pulse welds. Really aggressive pulse too. Low speed pulsing, without any filler by the looks of it.

91jdmhatchback

picture flipped


bisimoto header


Looks the same to me.

Agtronic

I would blame poor penetration, poor material (T304) and poor technique.

mikesrex

That's just pathetic that a company who obviously has someone smart enough to figure out how to do quality welds would cheap out on the welding process like that. I had a bad feeling about those headers when it seemed like the people pushing the products were no more than spammers who couldn't answer any technical questions...

9295EJ-t

iTrader: (1)

great prep, lazy welder... only time i usually dont use filler is on dumptubes.. and if he used filler, he didnt get good penetration..
never seen a crack like that form when filler was used though...

it looks like someone cut it with a band saw! i have never seen a break that bad! it's beautiful break!

dester223

I knew I should have cropped the header over a little bit more.

Pretty much all the welds are breaking like that. My buddy has it on his second car, so it's been on the car for about 2 months, but I don't think it has a ton of miles on it.

To me, it looks like a huge lack of filler. But when I see fuze welds, it normally looks really shallow. The header feels VERY light. I wonder if relieving stress like the full race manifolds (cut the flange) will help it last longer.

The last header that he received didn't even look like some of the runners were welded. As soon as we put it on and started the car, it was leaking where it wasn't welded. Couldn't see it @ first due to the coating that was put on the header.

all_motor_mike

wow............ havent heard that one before. nice going bisi's welder!


mike

dave@passenger

Filler or lack there of isn't likely to be much of an issue. You can build a NA header like this without filler, and not have failure. I've seen straight clean cracks like this before, both from lack of penetration or too much heat.

My guess is that he didn't purge, he had a gap on the fitup, material wasn't clean, and evidence of low speed pulse.

0Bisimoto

We offer a one year warrantee on defect in workmanship on all of our header units despite being an offroad/high performance piece. Bisimoto Engineering stands behind our products, and you can tell your friend to call in and it will be personally taken care of, even if it means that I replace the header with a brand new unit.

You also have my commitment that our fabricator will be disciplined properly if this is due to a welding issue. This issue will not occur again.

To Mike,
That is very low of you, as my sales associates are exactly what their titles imply: sales. If you have any technical questions, they can convey it from our staff engineers or I. Happy holidays.

dester223

Bisi, which contact # should I refer him to?

The only thing is this is his second header... I am not sure what he wants to do, but I will certainly pass the information back to him to contact you.

Garage 808 Hatch

What kind of mounts are on the car? Does the exhaust have a flex section in it? Not trying to place the blame away from the weld itself, but there car be contributing factors that will break a header much easier, than others.

CRMB

Low penetration. There had to be a significant percentage of metal that was still unwelded on the back side of that weld fail in that perfect little straight line like that.

dester223

Stock mounts with ES motor mount inserts in a 88-91 chassis.

And there is a flex section welded on the exhaust also. All the welds for the flex and the straight piece that goes back = good. I looked further into it today but the weld after the collector where it goes into the 2.5" pipe is also cracking.

welfarepc

dang thats savage.

im sure bisi will take care of it for you.