FEOA Forums banner

How-TO: HO Header

22K views 37 replies 23 participants last post by  ndlm8888 
#1 · (Edited)
its prety straight forward..

1) remove stock mani and cat
2) install ho header with new gasket.
3) plug egr passage, or install/modify the exhaust to hook it up if you would like. most installers cap/weld the hole up. this may throw the CEL over time for egr flow insufficient.
4) the exhaust may not line up exactly. the header collector area may be bent upwards, or downwards in respect to the factory exhaust, this may need bending or a re-weld the exhaust to fit.
 
#8 ·
^^^yeah, i think Escort Underground is no more...:(
 
#10 ·
OK I have had my HO header sitting around for a while, and I'm thinking about bumming some welder time from my neighbor over the holidays to tinker with mounting it up, along with my pacesetter GT exhaust & a hiflow cat.

At any rate, here are some photos I took to try and visualize/document what needs to be done. This seemed like the place to put them.

OK so here is the header mounted up on my junk head/block:


Here is roughly how it needs to sit, so that it doesn't hang down too low, and point at the floorpan too much (note: 1.9 block PCV removed, SPI's slimmer PCV chamber should be used):


Here is where I am planning on cutting the runners and re-welding them...probably at somewhat of an angle to help correct the tilt, but some torching on the bend will probably be necessary too:


Mounting flange, on head, just for reference (note at the very bottom you can see how the O2 sensor faces the driver side, backward from the SPI):


An idea of the spacing behind the header, in relation to the PCV vent in the block:


The tail end of the header, you can see the flange, and the EGR ports which will need to be plugged; mounting brackets are just out of sight at the bottom:


Clearance when mounted between the oil pan webbing (1.9 auto pan, btw) and the header. Cutting/torching/bending can alleviate this, but if you just bolt it up, it will be very close, ~15-30mm:


Of course, EGR provision will need to be made on the driver's side with a flange, for the SPI's EGR tube. In addition, a catalytic converter and a 2nd O2 sensor for 96+ cars will need to be setup past the header.
 
#12 ·
Just installed my HO header on my 2nd gen LX this week!

While I was doing the work for the header, I also changed the oil pan gasket, valve cover gasket, and 02 sensor.

My wagon is a '93, and luckily didn't have an EGR tube to hook up, so I welded over the two holes for the EGR setup on the 1st gen header. I used the PCV vent from a '97 ZX2, it certainly helped, but needed banged a bit itself in order to fit past the accessory bracket for the alternator. My car also has A/C, and that certainly makes the job of getting the header in place quite difficult - be warned. Once I got it past the A/C lines and tranny mount, it bolted in nicely, expect for the leftmost bolt that sits behind the alternator - I had to unbolt the alternator and move it back a few inches to gain access to the bolt. I installed all new bolts and washers, used high temp 1200 degree paint on the header, PCV vent, and valve cover. I had to extend the emissions hose for the PCV valve about 5 inches to accommodate the new vent. I bought the Bosch sensor for 50 bucks, and made sure I got the one with the 16.5 inch wiring harness - it needed it, since the 02 sensor bolts in to the opposite side of the HO header. I removed my radiator to gain better access to everything and that made things a bit easier, too.

The whole process, including all the prep work for mating surfaces of the valve cover, oil pan, and exhaust manifold locations, painting, etc. took me about 12-13 hours, about 100 bucks in gaskets and miscellaneous parts. I took it to a muffler shop the next day and had a new 2 inch exhaust put on it, straight with no cat, with a glasspack for 180 bucks. It sounds beautiful, has a nice crackle around 3000RPM, nice low grumble beneath that range, and is a very comfortable crusing at 60 MPH down the highway. The car pulls much smoother now, has a little better throttle response, and experiences less of those "dead" spots in the power band. In my opinion, it's well worth it. It made me fall in love with the 1.9 again.

My only complaint is that the header hangs too low, where the two pipes bend and go backwards. It hangs a bit lower than the transmission support crossmember, even. It also bends too far up towards the floor at the end of the header towards the collector pipe. I had the guys at the exhaust shop heat it and bend it to make it more parallel with the floor.

In addition, the header really needs a heat shield of some sort. I'm going to buy some plug wire heat insulators ASAP, because it gets REAL friggin' hot being inches from those pipes.

Hope this testimony helps those who are thinking of doing it. Here's some pics, feel free to PM with with any questions.







 
#17 ·
Yes, it will work on a 3rd gen.
 
#18 ·
no way !!!!

u guys cant be serious it took 13 hr to make ur headers fit it took me and two friends 2 hrs at most . one guy pulling ont the head side of the headers and one guy steping on the collector side while heated up the bend in the middle with 2 torches look .

it was frieken so easy and then i just welded the cat bach to the collector my exuast is all 1 peice from head to muffeler tip.
 
#21 ·
I just picked up my HO header from ghaze24 on Friday and I already started modding it for my 3rd gen. Here are some pictures of what I have done so far. By the time I am done it should fit like a glove. Thanks to the the notch, bend, weld method the collector is now straight instead of curving up.


I also completely removed the EGR connection. I don't have before pictures but it actually was sticking around 1/4" into the inside of the collector. It comes off vary cleanly if you cut it between the weld and the header. I welded a plate over the hole and now it should flow better. I also cut off one of the brackets that won't get used. I will cut the other one off as well and make my own once I see how it fits in the car.

The small connection was rusted really bad and it broke off when I tried to remove it. So, I cut it off and filled the hole with weld.

After looking at coldblooded's first pic I can see that this thing really curves away from the engine which makes it rub on a rubber ac line. I honestly think it could hit the fan shroud as well. This is what I plan on doing. Then it will sit closer to the motor like the factory setup. Of course then it will really curve up and I will have to lessen the bend. I also plan on shortening it so it will tuck up nicely and won't ever hit on the ground.

I also have an idea for making it hookup to the 3rd gen EGR. If my ideas work out then I will make the most epic HO header how-to this forum has ever seen.

Now here is some information I gathered from my header using a dial caliper. All the tubing before the collector is 1 3/4" and the collector is only 2" or slightly smaller. In my book this would make putting a 2 1/4" exhaust on your car pointless if you used this header. That's why when I do my exhaust it will be 2" throughout.
Now for some interesting facts about my stock exhaust that I discovered with the dial caliper. The catalytic converter pipe is 2". After the converter it briefly goes to 1 3/4", gets adapted to 2" for the flex pipe, then back down to 1 3/4", and by the time it gets to the muffler its 1 7/8". Am I the only one confused by this? It makes as much sence as the stock muffler's 1 7/8" in and 1 3/4" out. They should have just used 2" piping throughout! It must have cost them more to use two sizes of pipe and those adapter sleeves Vs. one size and no adapters. The assembly would have been faster to manufacture as well.
 
#22 ·
Well, today I cut the other bracket off and did what I talked about in the last post.
Before.

After. I ended up cutting out way more than I marked. This easily moves the header in at least 4" at the bottom. The line is where the right side of the level used to sit.

I know that now the bottom points up to the extent that the header won't fit the motor anymore. That will be addressed during the install as well as how low it sits compared to the stock setup.
 
#23 ·
Well, Wednesday and today got board and did more work on the header. I notched, bent, and welded the bend to get it back to about the same angle it originally had. I also cleaned up the welds and fixed any leaks I found. I know more work will have to be done but this is just about the limit to what I can do without using my car to mock it up.


 
#25 ·
I kind of wounder how much I will gain when I redo the system with this header. I plan to keep my 2" Magnaflow turbo muffler, use 2" stainless piping with mandrel bends through out, a glass pack resonator, and a new 2" cat.

For the EGR hookup I plan on getting another SPI EGR tube and using the flange to connect up to the current EGR and then welding the tubing to the header.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top