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DIY: Header Install

Joined
2 July 2003
Messages
1,436
Location
Virginia Beach
Ok... Due to all the questions I'm posting this up here to help some people out. Please note when I did this, I did it while I was putting everything ON... please use some imagination here folks. Anywho, here we go:

Removal of front header:

First thing I would do is remove the exhaust and also the front down pipe.
front downpipe bolts I sprayed lots of pb blaster on this prior to breaking... these 2 pictures are old pictures from the DIY Clutch Install a long time ago:

Link to DIY Clutch --> Clutch install


8071P1010039a-med.jpg


8071P1010043a-med.jpg


Then the down pipe drops and then remove the exhaust accordingly.

Now remove the small beam that goes across the rear, it does a trapezoid movement and holds the ebrake cables accordingly and then disconnect the front mount from the engine with the 3 bolts hooked to the block:

DSCN0823-1.jpg


Then the shifter cables:
DSCN0825-1.jpg


Then the majorly long bolts on the ends of the front beam.

This should drop the front beam and the front mount together.. If you have any issues with getting it out, go ahead and remove the long 17 that holds the mount to the beam. Honestly, you may want to loosen it anways b/c when you have to install it, you want all the play you can get initially.

Now you need to remove the AC compressor. *I was just recently told that removal of the compressor is optional... however for me I like to take this stuff off anyway because of the extra clearance it gives in working in that area*
This picture represents where the MOUNT for the AC compressor used to be:
DSCN0807-1.jpg


There were 4 bolts that held the mount to the block and two that held the mount to the side:
DSCN0811-1.jpg


And on the mount there were 4 bolts that held the compressor to the mount. Remove the 4 bolts on the compressor and then also disconnect the wire to the compressor and the whole compressor will drop.

*YOU DON'T HAVE TO REMOVE THE MOUNT TO GET THE INSTALL DONE* The only reason I did was b/c I know I'm not installing it back on. I'll tell you what though... with all that space installation of the headers was way easy.

Next step would be to remove the o2 sensor. It's a 22mm but I HIGHLY suggest to use an o2 sensor socket. Although I can tell you that even with the socket removal tool I couldn't get it off.

Now remove the heat shield cover off the header. You must remove this in order to get to the nuts that hold the header down.

*If you can't remove the o2 sensor you can do what I did which was use a dremel to cut a slit in the cover in order to pry the cover off. I basically ended up removing the header with the o2 sensor still on it.

After that make sure you use a SIX POINT socket to remove the nuts... they are really soft and will strip on you quicker than you can blink.

Don't freak out if the stud backs out with the nut. When I removed the rear bank, every single stud came out with the nut. You'll be ok.

At this point, the front header should be out.
DSCN0806-1.jpg



REAR BANK.
Remove the beam that hits the rear beam and the top which is actually the bottom of the trunk:
here are two of the 4 bolts:
DSCN0804-1.jpg


Now the rear bank is a little different from the front bank where the shield is a two piece shield.

Remove the o2 sensor, then the shield again.

Next... again remove the studs and weasel the headers out.

Installation is reverse of removal...

Oh yeah, when putting the extension pipes don't forget to install the gasket!
DSCN0819-1.jpg


Now for me I had a big issue. The test pipes did not line up with the exhaust:
DSCN0832.jpg


DSCN0831-1.jpg


DSCN0828-1.jpg


DSCN0826-1.jpg


So in order to fix this I noticed that the front bank test pipe needed to be shortened and the rear test pipe needed to be lengthened. So... here's what I did:

I cut the front bank pipe and mounted the header piece:
DSCN0833.jpg


And then after that I put the other half up to the other end, measured how much I needed to shorten and then just cut it. Rememeber... you can always have it too long and shorten it... but you can't be too short and add a piece (cleanly)...
here is what the pre-weld looked like:
DSCN0834.jpg



For the rear I put the piece to the header side and measured how much I needed to extend. FOR MY INSTALL, I added 2 1/8ths of an inch of pipe on the straight piece. Now yes I got it on properly but with hindsight, I think I would've preferred 2.25 of an inch of extra pipe. Here is what it ended up looking like:
DSCN0836.jpg

DSCN0835.jpg


When bringing this to the people to weld make sure you place some straight marks across the pipe so that the orientation of the flanges stays the same.

As you can see, it all came together accordingly.

Few notes:
1. Since I was unable to remove the o2 sensor I was forced to buy a new one. Since I hadn't replaced the front one yet, I figured it needed to be done anyway.
2. I HIGHLY recommend a set of nut extractors:
DSCN0805-1.jpg

3. When installing the gasket on the head please note the marking on the gasket that says: "Manifold Side"
DSCN0815-1.jpg

BUT don't worry, Honda was nice enough to make it such that if you put it on backwards, you can't bolt it all together.


total extra costs not including the header alone:
$70 for the o2 extension pigtail
$90 for the o2 sensor
$220 for the test pipe
$30 for the muffler shop to weld the test pipes and modify
$15 for extra grade 8 nuts and bolts to mount the test pipes.

Hope you guys appreciate this and that just like the DIY Clutch Install, it helps many people.
Any and all feedback is appreciated... happy wrenching!

Cheers,
x

P.S. - Someone asked me if having a lift would've made a difference in the install. To be honest, I've never had one so I wouldn't know the difference. However, I can say that doing this install nearly 100% is underneath the car, working on the ground wasn't too bad b/c I got to lie down. :)

P.S.2 - If anyone else has done this and knows that I missed a step, please say so... I started this post around 6:15 ish or so and it's too early to think right now.. :smile:
 
Last edited:
Very nice work! Saved to my personal archives although now I have done this a couple of times so I have somewhat down by memory. This would have been HUGE the first time.
 
Why didn't you us new gaskets? Did you fix the oil 'leak' too? Great write up.
 
goldNSX said:
Why didn't you us new gaskets? Did you fix the oil 'leak' too? Great write up.

You can reuse the metal gaskets as long as they are not damaged. The Cantrell header system comes with gaskets for the cats.

Oil 'leak' was from the previous install with the tranny, yes it was fixed, just a bad gasket..

x
 
This may be a bit late, and I certainly don't want to steal X's thunder, but I published an article on a DIY of headers in the NSXCA mag NSX Driver a while ago. It's pretty complete, with pictures and all. Here's a link to the original article, if you want to check it out. It's a 686K .DOC file.

DIYHeaders article.

Jeff
 
Jeff A said:
This may be a bit late, and I certainly don't want to steal X's thunder, but I published an article on a DIY of headers in the NSXCA mag NSX Driver a while ago. It's pretty complete, with pictures and all. Here's a link to the original article, if you want to check it out. It's a 686K .DOC file.

DIYHeaders article.

Jeff

:) It's cool... at least it was you...

Well then with that article and these pictures this thread becomes the most comprehensive thread for header install. Woot... good work Jeff!!

See you at the track!

x
 
Did you use new nuts and bolts on both ends of the test pipe? Are they stainless or rust proof? Any idea why the header-test pipes didn't line up with the exhaust?
 
VBNSX said:
Now for me I had a big issue. The test pipes did not line up with the exhaust:
.
.
.
So in order to fix this I noticed that the front bank test pipe needed to be shortened and the rear test pipe needed to be lengthened. So... here's what I did:
.
I cut the front bank pipe and mounted the header piece:
.
.
And then after that I put the other half up to the other end, measured how much I needed to shorten and then just cut it. Rememeber... you can always have it too long and shorten it... but you can't be too short and add a piece (cleanly)...
.
For the rear I put the piece to the header side and measured how much I needed to extend. FOR MY INSTALL, I added 2 1/8ths of an inch of pipe on the straight piece. Now yes I got it on properly but with hindsight, I think I would've preferred 2.25 of an inch of extra pipe.

This shouldn't happen! Do you know if the problem was with the header or the cat bypass pipes?
 
Don't freak out folks... was probably the test pipes... I'm sure everyone will be fine.

x
 
What brand test pipes were they?
I'm not using any but am hoping that just installing the headers is pretty straight forward and I don't run into any problems like you did.
 
I read the article in NSX Driver about doing this very thing as already alluded to in this thread. That article states it should take at best 6 hrs to do the job while the instructions that came with it say 4-5. Now I know we are talking only about an hour but the 6 hrs is basically saying if EVERYTHING goes exactly right and there are no hold ups or delays.
Can you say about how long it took you to do it.
I'm pretty sure I will do it myself and I'm not overly concerned with having the car down for several days while doing it since it's not a daily driver or anything.
 
When I was writing that article, I called the local acura dealer and asked how long it would take them to do it, and they said 6 hours minimum. My guestimate for a non-pro using home tools (and no lift) is 10 to 15 hours. That's how long it took me.

Here's a thread discussing this exact topic:

http://www.nsxprime.com/forums/showthread.php?t=254&highlight=header+installation


You should be able to get it done in a weekend, if you don't run into any major hangups.

Jeff
 
Took me around 12 hours in the garage with several breaks and a couple runs to autozone ;). Wish I saw these instructions back then, way better than the service manual: Remove beams. Remove bolts. Remove headers. Install is reverse.
 
hey VBNSX, I just read this complete thread and also your DIY Clutch thread. Thanks for taking the time to document your work. This takes a lot of time to do and I am sure that it has helped a lot of people out there, even if they don't take the time to Thank-You, I want to. This also gives a lot of guys the confidence to work on their car, after all it's just a Honda!

I am going to pull my tranny when I get home next spring to rebuild/inspect (syncro problems). I will pull the clutch out then and do the inspection on it also.

One thing that I didn't notice you making note of was, did you replace the rear main seal when you were in there? When I do my clutch I will replace it, even if it isn't leaking, cuz in another 80K miles it probably will be. Just a thought.

Great idea on the tranny jack from the chinamans shop. It looks affordable for the few times you would need it. I just love excuses to buy tools! The light aluminum floor jacks that they have are great too. I got one of them when I got home from Bosnia a few years ago. Man I use the heck out of it.

You would think that for the price of those test pipes that they would have fit. I once purchased a part for my old Luscombe airplane that didn't fit and they replaced the part and even gave me an allowance for some labor. It may not hurt to let the supplier know the problems that you had. You have it documented. Maybe their jigs got messed up.

Thanks
Brad
 
nsxer1110 said:
Nicely Done !

Great pics !

Im header shopping now !

g:)


make sure your exhaust is made specifically for the nsx

since i had a RM muffler custom made to fit a flow master muffler,

i can not use the headers until i get a new exhaust :(
 
NSXchnk said:
make sure your exhaust is made specifically for the nsx

since i had a RM muffler custom made to fit a flow master muffler,

i can not use the headers until i get a new exhaust :(

we talked about this... you just have to re-do the piping

x
 
OLDMNSX said:
hey VBNSX, I just read this complete thread and also your DIY Clutch thread. Thanks for taking the time to document your work. This takes a lot of time to do and I am sure that it has helped a lot of people out there, even if they don't take the time to Thank-You, I want to. This also gives a lot of guys the confidence to work on their car, after all it's just a Honda!

I am going to pull my tranny when I get home next spring to rebuild/inspect (syncro problems). I will pull the clutch out then and do the inspection on it also.

One thing that I didn't notice you making note of was, did you replace the rear main seal when you were in there? When I do my clutch I will replace it, even if it isn't leaking, cuz in another 80K miles it probably will be. Just a thought.

Great idea on the tranny jack from the chinamans shop. It looks affordable for the few times you would need it. I just love excuses to buy tools! The light aluminum floor jacks that they have are great too. I got one of them when I got home from Bosnia a few years ago. Man I use the heck out of it.

You would think that for the price of those test pipes that they would have fit. I once purchased a part for my old Luscombe airplane that didn't fit and they replaced the part and even gave me an allowance for some labor. It may not hurt to let the supplier know the problems that you had. You have it documented. Maybe their jigs got messed up.

Thanks
Brad

Thank you for the kind words... it helps knowing that all this information helps people out.

I just finished another install. With some assistance of someone who was mechanically inclined, we knocked the job out in just around 4 hours.

Just as an fyi, if you instant message me, and I'm not online you'll hit my phone. Feel free to use that for those who already haven't and have questions.

cheers,
x
 
92NSX said:
I'm going to get started on mine this weekend.
Did you remove your back wheels? I was going to back my car up on ramps.

No i didn't remove the rear wheels...

good luck!
x
 
Big thanks to X, he has been a lot of help a few weeks back during my install. :biggrin:

The only issue that I ran into was removing the front beam center bolt that bolts to the engine. You need a long enough extension (8 inch) to get to it, and start from the driver side..... you can't unlock the bolt from the passenger side.
Power tools will help.... saves me half the time.
 
92NSX said:
Are the bolts that hold Rod B supposed to be impossible to remove? I have a 1/2" air rathcet run by 150psi compressor and I couldn't get it to budge.:mad:

Sometimes they are... The exhaust shop had to cut one of the bolts off one the CATs on my '93 it was so bad.
 
Jeff A said:
This may be a bit late, and I certainly don't want to steal X's thunder, but I published an article on a DIY of headers in the NSXCA mag NSX Driver a while ago. It's pretty complete, with pictures and all. Here's a link to the original article, if you want to check it out. It's a 686K .DOC file.

DIYHeaders article.

Jeff

This should really be placed in the FAQ. Iused this as a step by step guide.
 
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