K20 project off to a good start, volume 2

[lookforjoe]

Nice work! Curious how long the collector is now it’s together. Can you please give me a measurement from the flange to the point where the runners enter the collector? I’m looking at DIY collector components, and 6” seems to be about the shortest I can buy (cone engineering). From your pics, I’d say it is around that length, but can’t be sure.

 

[kmead]

I spent several hours melting holes and laying beads down on a couple of sections of scrap exhaust pipe to try and learn to TIG weld. I finally got to the point where it was reasonable plus I was getting impatient to get on with my exhaust system so I decided to try the real deal. A guy who works at the body shop I use welded the cut header tubes back on the flange but I took it from there. I wanted to bring the exhaust straight back from the collector section of the header so that it will pass by the muffler and then elbow to connect to the catalytic converter. The way the shorty header comes, the collector angles towards the driver side of the car, so I cut a piece of exhaust pipe and fit it to the collector so that it would change the angle to be straight back. That first weld job got a bit rough at times, so I did a fair amount of grinding to get it smoothed out. Oh well, live and learn.

Next, I added one of the flanges for the V clamp. Better!! The welds were a lot smoother and cleaner and I didn't need to grind any of it. Then I added the bung for the O2 sensor. That came out better yet. Even played with the amount of post flow to get some of that cool blue color in the welds that some people like. Here is the final header. Don't get too critical as it is my first try at welding.
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Here are a couple of photos of it in position.
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Man you really suck at this. You should totally put that thing back in the box and mail it to me. I’ll pay the postage to keep you from doing any more damage.

Nice job. Nothing like getting ballsy with your first try. Very nice indeed.

Gives me hope that maybe I can relearn something from my distant youth and even add to it.

That viewing of welding porn certainly paid off!

 

[Rodger]

Nice work! Curious how long the collector is now it’s together. Can you please give me a measurement from the flange to the point where the runners enter the collector? I’m looking at DIY collector components, and 6” seems to be about the shortest I can buy (cone engineering). From your pics, I’d say it is around that length, but can’t be sure.

I was dropping the header off at a local general machine shop to have the flange milled flat as it was warped after the header tubes were rewelded. I saw your post so I took a couple of quick photos. Hope these help.

 

[rx1900]

Hey Rodger. That looks REALLY good !!! Well done. Looks like you have learned another new skill. Tried the MIG function yet ? I think you will find it much easier than the TIG.

Hate to make more work for you.....but you really should think about bracing your fancy new header. To avoid cracking in the future.

Look at the original RSX manifold. I think it too was a tubular design:
https://www.acuraoemparts.com/auto-...anual-engine/engine-cat/exhaust-manifold-scat

Note there appears to be a brace from the engine block to the end flange of the manifold ? Most all OE manifolds are braced like this. And with good reason - they would not do it otherwise !! It is there partially to take some weight and stress off the manifold, but mostly to quell the vibration. Otherwise the end of the header is like the end of a whip as the vibrations get amplified.

Generally, without a brace, the header will eventually crack where the tubes are welded to the header flange at the head. Usually a case of when, not if....

May not be an issue for you if you dont put many miles on it, but still....

Do you still have the original brace from the OE manifold ? Could you weld a bracket onto your new header and modify it to fit ? At least maybe think about it.......

 

[Rodger]

Hey Rodger. That looks REALLY good !!! Well done. Looks like you have learned another new skill. Tried the MIG function yet ? I think you will find it much easier than the TIG.

Hate to make more work for you.....but you really should think about bracing your fancy new header. To avoid cracking in the future.

Look at the original RSX manifold. I think it too was a tubular design:
https://www.acuraoemparts.com/auto-...anual-engine/engine-cat/exhaust-manifold-scat

Note there appears to be a brace from the engine block to the end flange of the manifold ? Most all OE manifolds are braced like this. And with good reason - they would not do it otherwise !! It is there partially to take some weight and stress off the manifold, but mostly to quell the vibration. Otherwise the end of the header is like the end of a whip as the vibrations get amplified.

Generally, without a brace, the header will eventually crack where the tubes are welded to the header flange at the head. Usually a case of when, not if....

May not be an issue for you if you dont put many miles on it, but still....

Do you still have the original brace from the OE manifold ? Could you weld a bracket onto your new header and modify it to fit ? At least maybe think about it.......

Hi Doug. Thanks for the kudos. The header came with the bracing bracket on it, but I cut that off to get it shorter and to allow me to change the direction to straight back sooner. I don't have the bracing bracket from the original either as the body shop tossed the header during the fitment process as it is in the way. I have heard of the cracking issue and I was thinking about that when I have looked at some of the MWB build photos that I could find. From what I could tell, the entire system was connected rigidly to the header which would seem to create a lot of stress on those welds. Not sure if any of their builds have had issues with the headers cracking. That is why I have a flex coupling planned on the next section. Plus I want to have all of the weight of the muffler/cat/tailpipe section held by the mounting springs and not weighing on the header. I will take a look at the mounting bracket though and where it would bolt to the block. Thanks for the feedback!

 

[lookforjoe]

Thank you for the reference pics, those are definitely helpful. I should be able to work with the cone engineering collector, I can shorten it slightly to get it into the approx 5” overall depth off the runners.

The work looks good, you definitely should feel good about the overall quality of the welds. Hey, as long as it doesn’t leak, the rest is gravy.

EDIT: bringing this up from the last page. You also have a good angle on the O2 sensor to prevent moisture damage. The welds look good on the inside, from what I can see.

The one last measurement that would be most helpful is the overall drop from the flange to the underside of the collector when viewed from the end (see attachment):

 

[Rodger]

The one last measurement that would be most helpful is the overall drop from the flange to the underside of the collector when viewed from the end (see attachment):

Right now the header is at the machine shop. Once I get it back I will make those measurements for you.

 

[lookforjoe]

Right now the header is at the machine shop. Once I get it back I will make those measurements for you.

Thanks, Rodger. I meant to include that in fact request, once they are back from the shop

I had to go with a 6" (2" inlets, 3" outlet) collector, the shorter cone ends up being more than 3" ID. I'll likely either shorten the runners slightly to compensate, or run the cat behind the muffler as you are planning. In truth, I have had zero issues with the cat in front & on top of the muffler for these past number of years, but I'll move it around based on how the header depth comes out.

 

[Rodger]

Thanks, Rodger. I meant to include that in fact request, once they are back from the shop

I had to go with a 6" (2" inlets, 3" outlet) collector, the shorter cone ends up being more than 3" ID. I'll likely either shorten the runners slightly to compensate, or run the cat behind the muffler as you are planning. In truth, I have had zero issues with the cat in front & on top of the muffler for these past number of years, but I'll move it around based on how the header depth comes out.

Looking forward to seeing your custom header. If you design it so that the outlet of the collector is more to the passenger side of the opening into the muffler bay, it will give you a lot more flexibility in the muffler position than with the off the shelf shorty header.

 

[Rodger]

I'm giving the exhaust system a break until I get the header back from the machinist. I decided to finish up the brake system. I decided to get the 38 mm rear calipers from Autoricambi that Yves had mentioned a little while back. I had upgraded to the Wilwood system up front and everyone seems to say that the stock rears are just not a good match for that. Fortunately, I hadn't gotten around to filling the system so no mess. I swapped out the rear calipers and then bled the whole brake system. Pedal feel seems pretty good, but I won't really know until drive time. I also finished getting the parking brake installed and adjusted.

Next I started to tackle the interior. First, I put down some Dynamat and then will start to wrestle with the carpet next.

 

[stingray250]

I'm giving the exhaust system a break until I get the header back from the machinist. I decided to finish up the brake system. I decided to get the 38 mm rear calipers from Autoricambi that Yves had mentioned a little while back. I had upgraded to the Wilwood system up front and everyone seems to say that the stock rears are just not a good match for that. Fortunately, I hadn't gotten around to filling the system so no mess. I swapped out the rear calipers and then bled the whole brake system. Pedal feel seems pretty good, but I won't really know until drive time. I also finished getting the parking brake installed and adjusted.

Next I started to tackle the interior. First, I put down some Dynamat and then will start to wrestle with the carpet next.


Dynamat????

I used this stuff extensively https://www.lowes.com/pd/Peel-Seal-...s-6-in-x-25-ft-Aluminum-Roll-Flashing/1018733 on my VW build... Really good adhesive/thickness and cheaper than Dynamat.

 

[lookforjoe]

Interesting. What weight is it though? The Dynamat functions as a damper, most of those generic butyl rolls are too thin to function as a vibration damper.

 

[Rodger]

It never ceases to amaze me at how the time flies by on the various parts of this build. I decided to put together the glove box door. First, I had to find where I stashed all of the pieces of it. The original dash was brown and totally toasted from years in the California sun. Over the past few years, I had acquired a NOS black dash, a NOS black glove box lid, a used black lid back, and new screws to hold them together (as the originals were really rusted). Of course, all were in different places so that took a while. I still haven't found all of the hinge pieces from the original car. I did find the original lock, but when I bought the car, it only had one door key that just fit the driver's door lock but none of the others. Turned out that that door was not the original. I had purchased a new set of door locks and release levers from Henk, so I wanted to see if I could re-key the glove box lock to match.

I took a little while to figure out how to disassemble the lock, but it was interesting to see how it worked. I rearranged the little sliding metal shims that the key moves and modified a couple of them to fit the new key and then put it back together.

Installed it in the back plate and then put the lid together. Four hours give or take..... This whole build reminds me of the advice on how to eat an elephant.

 

[Tom Ginefra]

Sometimes...it's the little things!
And now you're a locksmith, too!

 

[lookforjoe]

Nice work! I had to do a similar thing in the sense that my lock cylinder was damaged (can't find pics, or recall why), so I used an old Volvo lock & re-keyed it as you did for the Fiat key.

As I was reading this, I just realized I was conflating your build & Clarks' dash & wondering why would you fix the glovebox door

 

[Rodger]

Clark’s dash creation project is truly amazing but if I were to add something like that to this project, yikes. I can’t even conceive of the time. I actually like the stock dash look, but remember, I bought my first X in ‘79 when that interior refresh was introduced and have looked at it for almost 40 years. It like an old friend.

 

[Rodger]

I put the dashboard in today. I am starting to feel like the end is in sight.

Of course, I had it all bolted down, then tried to put my custom modified defroster manifold in and found that I could not get it in. Unbolted the dash and pulled it out a bit and then was able to slip it in. Re-bolted it all in and added the AC hoses to the side dash vents.

I found the glove box door hinge parts (yeah!) so installed the door. What a PITA that was! Trying to get all of the little washers and the parts lined up with the door, then getting the bolt threaded into the pawl was really frustrating. I must have had it come apart 5 or 6 times with the little washers dropping through the dash. Finally figured out how to clamp the pawl in place and then carefully was able to start the bolt while holding it with a needle nose pliers. No room to get my fingers in there to start it by hand.

I filled in a couple of common cracks in the instrument pod surround and painted it with the flat back Duplicolor vinyl paint. Looked really good.

 

[motoTrooper]

Brilliant inspiring progress Rodger

 

[Rodger]

After what seemed like an eternity, the machine shop finally finished milling the flange on my header flat. There was a lot of discussion with him on how to do it as it is such an odd shaped piece and he was trying to figure out the best way to clamp it steady. Now I can start on the rest of the exhaust system if I can remember how to weld again.

 

[lookforjoe]

Ports look good.

If you don't mind noting that offset measurement for me, that would be great