This question has been in the back of my mind ever since I first saw the JUN header years ago, so I figured it might make for an interesting discussion. The header is a basic, common looking 4-2-1, but it does have one distinct feature with a purpose that I have yet to figure out. If you look at the picture below (borrowed from StreetSports.com), you'll note two "triangles" on the outer primaries near the flange. These triangles are flat pieces that have been welded-in where a section of the tubing was cut out (at least I'm relatively certain that the tubing was cut out).



My first impression was that they're intended to increase power somehow (perhaps in a similar fashion to D-shaped primaries), but then why are they only present on two of the tubes? Any ideas?


Modified by Padawan at 4:53 PM 4/18/2004

 

I have Jun 4-2-1 header and do not have those welds.
Not sure why the one pictured does.

 

these weld spots is where oem header would have brackets for heatsheld..

 

I've also noticed that on many JUN headers.

 

I have that on my jun header too...I think it is for looks??

not sure

 

It was put there just so that people would ask about it on internet forums.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Kendall &raquo;</TD></TR><TR><TD CLASS="quote">It was put there just so that people would ask about it on internet forums. </TD></TR></TABLE>

lol.. never seen jun header.. but wondering is its a polished oem header of some type.. just like spoom cam gears and some products.. how does ctr header look like?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vtec.dc2 &raquo;</TD></TR><TR><TD CLASS="quote">lol.. never seen jun header.. but wondering is its a polished oem header of some type.. just like spoom cam gears and some products.. how does ctr header look like?</TD></TR></TABLE>

It's a very nice piece, not just a reworked OEM piece (not sure how that would work anyway), I've only seen two in person. The CTR came stock with just a typical exhaust manifold, nothing special.

 

A different, clearer photo borrowed from member "jfoster":



I'm still at a loss to explain the triangles. On a side note, from the pictures I've been looking at, the header's build quality appears to be excellent.


Modified by Padawan at 12:33 AM 4/18/2004

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vtec.dc2 &raquo;</TD></TR><TR><TD CLASS="quote">but wondering if its a polished oem header of some type.</TD></TR></TABLE>

i believe that the feels header and the jun header are identical; simply a case of feels and jun using the same company to build. user "110 south" has the feels and user "mikehonda" has the jun. they are, as far as i know, completely custom manufacturered headers; not based on the oem design.

kepani

 

Interesting. Here's mine:

 

Perhaps this was done to simply allow a socket/box end wrench to be to fit on the bolt/stud that goes into the head.
The primaries for cylinder 2 and 3 seem to be at a slightly different angle due to the fact that they extend over the cyl 1 and 4 primaries, and the welding/cutting of the pipe might not have been needed there.

-K, who's playing the header's advocate

 

I thought about that possibility too, but then if anything, it seems to me that the inner two primaries would need the extra clearance for the bolts, not the outer. It's difficult to tell from ntt's above photo, but it looks as if there are "dents" in the same locations as the triangles in the other photos. Perhaps you're right about the clearance, but I'm still not sure why it would be necessary for those two tubes, since again, their angles would seem to offer more clearance than the other two.

 

Maybe reinforcement? Make sure that if they're being pulled down they won't crack/bend as easily?

So far I'm with <TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Kendall &raquo;</TD></TR><TR><TD CLASS="quote">It was put there just so that people would ask about it on internet forums. </TD></TR></TABLE>

 

I just emailed JUN about it, so hopefully they'll be able to explain the mystery.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vtec.dc2 &raquo;</TD></TR><TR><TD CLASS="quote">these weld spots is where oem header would have brackets for heatsheld..</TD></TR></TABLE>
arent most of these header copy molds of 4-2-1 itr headers? so the fact that there are weld spots in same location as the heatsheild bracket would make sense.

 

The 4-2-1 found on the 96-spec ITR and CTR are cast manifolds, not tubular like the 98-spec 4-1. As Kendall said, the JUN header is an original design, not a reworked factory piece.

 

i smell fake jun header

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by integrasi &raquo;</TD></TR><TR><TD CLASS="quote">i smell fake jun header</TD></TR></TABLE>

I'm not sure what you mean, but the two photos I posted (and the header that I saw in person) were genuine JUN manifolds all featuring the "triangles".

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by integrasi &raquo;</TD></TR><TR><TD CLASS="quote">i smell fake jun header</TD></TR></TABLE>

lol...it's real...mine is like that too

 

well, thats funny, cause my jun header does not have it.

 

nor does mine

 

my guess is that they are unable to make the tubes "fit" the openings nicely there, due to the angle of the pipes and their close proximity to the motor. See how the curve o nteh pipe is right up to the end while on the two inner pipes since they are more vertical and further away from teh motor they have a little striaght section before the end? i'll bet it is easier to stretch the pipes in the straight section to match the oblong shape of the openings, while the two outers they have to cut, then weld in a little patch to be able to nicely match the port shape.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Safir &raquo;</TD></TR><TR><TD CLASS="quote">my guess is that they are unable to make the tubes "fit" the openings nicely there, due to the angle of the pipes and their close proximity to the motor. See how the curve o nteh pipe is right up to the end while on the two inner pipes since they are more vertical and further away from teh motor they have a little striaght section before the end? i'll bet it is easier to stretch the pipes in the straight section to match the oblong shape of the openings, while the two outers they have to cut, then weld in a little patch to be able to nicely match the port shape.</TD></TR></TABLE>

Now that is a distinct possibility. I wonder, though, why it seems that some of the JUN headers don't have these pieces, and which ones are actually the "new" version.

 

maybe on some those pieces of metal were added on to make the tubes <U>thick enough </U>there so that people could add nuts to bolt down a heatshield if they wanted to run a heatshield from a jdm-4-1 oem header?