Replacing cast iron manifolds with OEM tube headers

[NSXcitement]

I've had the parts ready for just about ever, and since it looks like the rain is never going to end, I figure now is the time to do it. Thought I'd go ahead and start a thread since there's sure to be some questions arise along the way.

Cover me, I'm goin in.

 

[dablackgoku1234]

I hope you have a full 97+ exhaust system and not just the headers.

 

[Jinks]

I've had the parts ready for just about ever, and since it looks like the rain is never going to end, I figure now is the time to do it. Thought I'd go ahead and start a thread since there's sure to be some questions arise along the way.

Cover me, I'm goin in.

View attachment 123495

Good luck buddy! Headers was something I whimped out on as a do it yourselfer.

 

[robbiedawg]

see post 10 for a hilarious account of one man's mishaps-
http://www.nsxprime.com/forum/showt...ourself-or-not?p=164387&viewfull=1#post164387

 

[Jinks]

Indeed it was very funny. Well written too. It is reasons like these I want a 4 point lift.

 

[robbiedawg]

this story reminds me i have no mechanical ability,and i need to pay other people to work on my car.to the op,good man for taking this on.

 

[NSXcitement]

I hope you have a full 97+ exhaust system and not just the headers.

I've got the 97-99 OEM headers, along with the SOS adapters
https://www.scienceofspeed.com/inde...997-99-header-conversion-for-1991-94-nsx.html

Had Swain apply their "White Lightning" coating to the headers


SOS adapters and SOS hi-flo cats


CT Gen II Exhaust

Good luck buddy! Headers was something I whimped out on as a do it yourselfer.

Thanks man! Had a pretty good day today. Got the all the easy stuff done (stock muffler and cats out, and rear exhaust manifold out) with only 1 trip to the auto parts store and one boo-boo requiring first aid. What remains will be a lot tougher. Got some Mother's Day activities in the middle of the day tomorrow, so depending on how sore I am tomorrow morning, I may just take the day off. I've also got parts to update my tranny (JDM gears, 4.23 rear, aluminum flywheel) and I'm kinda thinking I might as well do it all now. I'm not getting any younger.

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I'm hoping someone out there has seen this before and can identify the grey goop. It's thrown onto the CV shield in a line corresponding to the inner edge of the inner axle boot on the passenger side. Is it a mixture of oil and water, or grease coming out of the boot?

 

[NSXcitement]

A photo of the CV joint itself. The boot appears to be in good shape.


I noticed this machined casting has an area of displaced metal, like it had been hit with something. This area is normally covered by the CV shield, so I don't know what happened here. Maybe a hammer was used to coax it off during some prior maint/repair.


The rear bank has a little oil weep from each end of the valve cover. Enough to form a drop on the round plug you see in the photo, but not bad enough to drip. Not sure if I want to tackle that fix or not. Can the valve covers be removed with the engine in place? I'll have to do a little research.

 

[Hass]

I had hell of a time on a lift, all my bolts were rusted. I give props to everyone that do all the work at home. I was covered in dirt and oil it was worth it.

 

[DreamPowered]

Having done my install 2 weeks ago, I'm wish you the best of luck and will have a drink for you later tonight when I get home.
Never want to do a header install again.

 

[B2FiNiTY]

The grey goop is definitely axle grease.

And yes, you can remove the valve covers with the engine still in place.

 

[Kaz-kzukNA1]

Hi, NSXcitement.
Could be too late but you may find some of the info in the following link useful;
http://www.nsxprime.com/forum/showt...ts-on-a-1991?p=1667469&viewfull=1#post1667469

Addition to this, as recommended by other owners in many threads, you may want to replace your existing exh manifold stud bolts with the later spec shorter ones used on NA2 model.

Take your time and good luck.

Kaz

 

[NSXcitement]

Hi, NSXcitement.
Could be too late but you may find some of the info in the following link useful;
http://www.nsxprime.com/forum/showt...ts-on-a-1991?p=1667469&viewfull=1#post1667469

Thanks for the tip. I went ahead and bought NA2 gaskets and nuts, but I only bought a few studs in case some backed out. Tried loosening the 17mm fasteners securing the crossmember today. Man, those things are really in there. Need a longer breaker bar. Still debating about whether to do the transmission mods now. Been spending a lot of time with the shop manual.

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The grey goop is definitely axle grease.

Wonder if adding a big (8mm wide) tie wrap on top of the existing metal band would stop the flow. I think what I'll do is clean everything up, put it back together, and then remove the shield and inspect it after 500mi or so, in order to see how much is coming out.

And yes, you can remove the valve covers with the engine still in place.

Oh boy! I think I'll wait till I can get a good look at the front one. If it's leaking worse, it's the one I'll try first.

 

[NSXcitement]

Decided to clean things up as I go; or try to anyway. Cleaning takes a lot more time than the wrenching, so at some point I'll probably have to draw the line. I failed to take a "before" photo, but here's the crossmember after giving it a good scrubbing.