F22A Bisimoto Header Detailed Photos

[Macaqueistrong]

So, the question becomes:

Is the cost of fixing the leak (welding the slips on), and adding a flange to the collector worth the price/performance? This would assume a used Bisi header, as apparently the consensus is that there's no reason to buy a new one if it's broken out of the box.

Exactly.

After really looking at the header the other issue is, you dont really have a whole lot of room to cut the downpipe after the collector to weld in a flange.



Look at the placement of the oxygen sensor bung. You would have to weld the flange below that, but then you are pretty much right on the bend that goes under the block. Plus the header hugs the block so tightly that you would never be able to fit the header and down pipe onto the car because the flange would most likely be directly up against the block.

[Macaqueistrong]

I believe it might be preventable with a hose clamp or equivalent. Header wrap might be an alternative too.

After fitting and re-fitting this header all weekend long, I've just decided to get some header wrap and wrap around where the collector and primaries slip together.

I've gotten the gap to be completely closed and it still leaks the same as it did with the bigger gap. I've tried to install this thing every way possible besides installing it as 1 complete piece which shouldn't even be an option. with absolutely no change in the leak.

I'm done with trying to make it work. If header wrap destroys the welds or doesn't help the leak then, I'm just gonna have a custom header made.

[cloudasc]

I've been thinking about the leaky header issue, and a question that comes to mind is: Has anyone measured the size of each primary as part of the "ram horn" where it slips into the collector, and the opening of each port of the collector?

I'm curious as to the diameters of each tube/primary on both the "ram horn" part, and collector to see if there is a size discrepancy between them.

[oyajicool]

Since you have your own header bought 2 yeas ago, why don't you see that with your own eyes. See how well they fit. There's no need to know exact dimensions of ID and OD there, really.

[cloudasc]

Since you have your own header bought 2 yeas ago, why don't you see that with your own eyes. See how well they fit. There's no need to know exact dimensions of ID and OD there, really.

EDIT: I am not the one complaining of fitment issues here, so it would be better to get the numbers from people who are having the issue.

What I am saying is to see if the ID/OD of each port is the same between #1 to #4, or if there is a difference, and where the difference is that is causing the issue. Obviously the collector for one port is too big, but I am trying to figure out if that same port is the same size as the others on the collector, or if one of the pipes for the "ram horn" is smaller then the others... Do you understand what I am trying to get at?

[reklipz]

I follow your logic cloud.

From your photos, the number 3 primary looks like the jig doesn't properly align the final piece; it looks like the bottom is slightly cocked by a few degrees compared to the others. Perhaps that's just the photo though.

[oyajicool]

How logic is that to have a header assembled with differing pipe sizes for the same section of the header????? The same distance from exhaust ports????

Is this one way to tune an engine?????

This logic is beyond my ability to comprehend.

[cloudasc]

How logic is that to have a header assembled with differing pipe sizes for the same section of the header????? The same distance from exhaust ports????

Is this one way to tune an engine?????

This logic is beyond my ability to comprehend.

The source of the pipes/bends could have made a mistake and shipped out the wrong sized tubes, and QA never checked before they were welded together.

I am just trying to figure out where the issue is, you know... what the exact "fuck up" is/was. Once you know the exact cause/issue/error, the resolution/fix should be easy.

Quit your bitchin and get to fixin!

[oyajicool]

You'll join me bitching once you installed your pipe and drive your car.

I have my own theory and observation as to why this POS is leaking. Until I try and make it work, I will keep it myself in order to avoid confusing people.

[GhostAccord]

How logic is that to have a header assembled with differing pipe sizes for the same section of the header????? The same distance from exhaust ports????

Is this one way to tune an engine?????

This logic is beyond my ability to comprehend.

If you are referring to the larger diameter pipe around the bends and the other equal steps...then yes! That is a very common way to maintain velocity in a tight curve through a piping system. In this case it happens to be used in an exhaust pipe. There are formulas for designing such systems. Fluid and thermal dynamics. I'm not going to bother getting into it in any great detail.

Now if you are referring to the larger pipes used for the slip fit. That's just the way they are. The looser they are the more they will tend to leak. Not what I consider the best design for a daily driver in any situation. That being said, I have been around and worked on enough street bikes to see that they use slip fit throughout there entire exhaust system. Very rarely have I seen them have these sort of fitment issues.

[reklipz]

If you are referring to the larger diameter pipe around the bends and the other equal steps...then yes! That is a very common way to maintain velocity in a tight curve through a piping system. In this case it happens to be used in an exhaust pipe. There are formulas for designing such systems. Fluid and thermal dynamics. I'm not going to bother getting into it in any great detail.

Now if you are referring to the larger pipes used for the slip fit. That's just the way they are. The looser they are the more they will tend to leak. Not what I consider the best design for a daily driver in any situation. That being said, I have been around and worked on enough street bikes to see that they use slip fit throughout there entire exhaust system. Very rarely have I seen them have these sort of fitment issues.

What he's saying is that it would be stupid for Bisi to design the header such that the OD used on the ends of the primaries, and the ID used for the sleeves, to be different depending upon the primary/sleeve. He's misunderstanding cloud's notion, and this is his response. cloud isn't suggesting that Bisi would go to the trouble of purposefully doing something like that. Instead, he's suggesting someone actually check these numbers on a leaky/"faulty" unit to ensure that nothing stupid happened during manufacturing, or even that excessive heat didn't allow any stress from poor fitment to cause the slips to widen. Sounds logical to me.

[oyajicool]

If you are referring to the larger diameter pipe around the bends and the other equal steps...then yes! That is a very common way to maintain velocity in a tight curve through a piping system. In this case it happens to be used in an exhaust pipe. There are formulas for designing such systems. Fluid and thermal dynamics. I'm not going to bother getting into it in any great detail.

Now if you are referring to the larger pipes used for the slip fit. That's just the way they are. The looser they are the more they will tend to leak. Not what I consider the best design for a daily driver in any situation. That being said, I have been around and worked on enough street bikes to see that they use slip fit throughout there entire exhaust system. Very rarely have I seen them have these sort of fitment issues.

I invite you to have a close look at the photos on this thread.
I've been an FAA certified A&P since 1982. I've been an IA since 2005. I, too, know a thing or two about wrenching.

[ferenza]

Has anyone thought about these?


Exhaust Band clamps

I think these might work.They are cheap and thin enough to fit around the offending collector(s).I helped installed one on my buds mk2 jetta that has a slip-fit catback system and he hasnt had ANY leaks yet .Give this a try. They are around $10 each at autozone or pepboys(or which ever auto store)

Edit : they squeeze hella tight and forms over the pipes

[Joey GT-R]

You might want to fix your pics as well as provide a link.

[GhostAccord]

I invite you to have a close look at the photos on this thread.

I looked at all the pictures in this thread..... What different diameter pipes are you referring to? I see a few areas in the images that have varying diameters of piping.

I've been an FAA certified A&P since 1982. I've been an IA since 2005. I, too, know a thing or two about wrenching.

I am sorry if I sounded condescending. I am not familiar with the scope of your work. I just assumed that you were seriously looking for an answer to your question.