JBA Header Install
NOTE – this is "in process". I still need to fill in some of the bolt sizes, part #’s, etc.
NOTE - This procedure is specific to JBA headers on a single cat (94/95) car. Other brands and cars WILL be different. Even the JBA ’93 install is slightly different.
PARTS/SUPPLIES LIST:
O2 Sensors – If replacing: AC/Delco AFS-75 (2 required)
O2 Sensor anti-seize – reusing old sensors: Goodwrench PN 12377953
AC/Delco PN 10-102
Anti-Seize for aluminum heads: Permatex #133A Anti-Seize Lubricant
Gasket Sealer: Permatex #101BR Sensor-Safe Ultra Copper Hi-Temp RTV Silicone
CAUTION: Do NOT use any lubricants, spray, sealers, etc. containing silicon. This can contaminate your O2 sensors and damage them.
PREPARATION:
1) Wash the front end. Make sure the tops of the fenders are clean, to avoid scratches and swirls.
2) If you have a shock tower brace, remove it.
3) Read the instructions. There are a couple of fuzzy areas:
a) They tell you there are two "air tube" connections on the passenger side. Actually, there is one air tube at the front for the A.I.R. connection, and a connection on the tube from #8 for the EGR tube.
b) They don’t mention pulling the oil dipstick tube out. You will need to do this.
c) Don’t install the O2 sensors until the headers are in. There is no access problem. See below regarding threads.
d) If you have new AC O2 sensors, you will not need a sealant on the sensors. They come with the correct O2 sensor safe anti-seize already applied to them. If you are reusing your old O2 sensors, you will need a sensor safe, electric conductive sealer (see above)
4) The headers come with bolts and gaskets. You can improve the quality of these, if you wish, and you will need some other supplies:
a) For the gaskets, look at the Mr. Gasket CopperSeal, specifically for the LT1….they are a D-port. The ones for the "small block Chevy" will NOT work. They run about $40, but they do not require a sealant to be applied. They are solid copper, fairly thick, with raised ridges to seal to the header flange.
b) For bolts, look at the Stage 8 locking bolts. They have both a hex head and an Allen key, and they include small D-washers and spring-ring locking clips. About $30. Another possibility is a set by ARP, but I don’t think those are "locking". They do have a special 12-point head though.
c) You need anti-seize compound for the bolts that go into the aluminum heads – the header bolts, and the spark plugs you remove.
d) You will still need sealant for the collector gaskets that connect the headers to the y-pipe. Or you can use Flow Tech "dead soft" aluminum gaskets, or you can use solid copper gaskets here too, or just use the ones that come with the headers. They are not hard to replace if they leak. The sealer is Permatex Ultra-Copper High Temp Sealant, and this is O2 sensor safe. Check, but I think the collectors are 2-1/2".
5) Check the flange of the headers for straightness. Mine were fine, but a friend’s AS&M’s were warped enough that he had them planed. If they are not straight, they will probably leak. Just put a straight-edge or level across them. Then hold the gasket up to them and make sure the bolt holes are in the right place.
6) Check the bolt hole to mount the EGR tube to the passenger side header to be sure it is threaded. Mine wasn’t. I tapped it with a 5/16-18 tap.
7) Trial fit the O2 sensors, and when you remove them, the A.I.R. connector threads. The cerametallic coating can make the threads hard to start. If you have an old sensor, you can use it to chase the threads. Then put it aside and install the sensors at the end. It could be hard to get the threads started if you are doing this after the headers are installed, and you are tied up in knots trying to reach them.
8) A thought about spark plug wires. If you are going to change them, this is the best time to do it, with the manifolds out. You will need to think about how the factory wire routings will relate to the finished header location. I was installing an Electromotive SDI at the same time as my headers, so I did not need the factory wires any more. The Electromotive coil pack sits on top of the driver’s side rocker cover, and the wires will route cleanly from the top, through the headers. Since I no longer have my factory wires, I can not give any advice on whether the factory routing is completely compatible with the header install. It looks like it will be OK. The header tubes are well out from the heads, but you will need to check this for yourself. There are braided fiberglass "socks" that fit over the plug connectors. You might want to think about using these to prevent wire burns from the headers. You’re on your own at this point.
JACK THE CAR:
9) Jack the front end, get the plastic pads behind the front wheels about 15 inches off the ground and put jack stands under the plastic pads. It says, "Do not jack", but this means do not use your factory scissor jack under the metal rocker panel at that point. You can use the pads for jack stands.
10) An alternative is to raise the entire car off the ground. I backed mine into the garage, putting the back wheels up on my ramps, then jacked the front end.
11) Don’t go any higher than indicated. You need to work from the top and from the bottom, and this puts it just high enough to get under it and low enough to work from the top. You do not need any more room than this to get the manifolds out or the headers in.
PREPARE TO WORK:
12) Put soft, clean cotton towels on the tops of the fenders, tape them if necessary, and cover them with thick, resilient fender pads.
13) Generally, it is recommended that you disconnect the battery at this point. You will be pushing and pulling a lot of metal parts through the engine compartment, and you could short something out. Remember your radio security code!
14) Get a good quality penetrating oil and saturate all the bolts and studs you will need to remove. I used WD-40, and it wasn’t good enough. Try Liquid Wrench or similar. Do this at least 24 hours before you will start, if possible. This includes:
a) The bolts in the outlet end of the catalytic converter
b) The nuts/studs connecting the Y-pipe to the manifolds
c) The six bolts and studs on each side holding the manifolds to the head. (These are actually fairly easy to get out, since the factory appears to have used generous quantities of anti-seize.)
d) The A.I.R. threaded connectors on top of the manifolds (one each side).
Y-PIPE REMOVAL:
15) Remove the two bolts that hold the catalyst flange to the intermediate pipe, and loosen the two bolts that hold the flange to the support bracket. Remove only one of the bracket bolts.
16) Go to the Y-pipe/manifold connections. There is no need to remove the O2 sensors. You need a long extension and a xx mm socket. There are three studs/nuts per connection. You will probably break a few. No problem. You aren’t going to use the manifolds or the Y-pipe again. Be gentle with the O2 sensors, particularly if you plan to reuse them. This might be a good time to replace them, if they have 50,000 or more miles on them.
17) Remove the last bolt at the cat outlet, and drop the pipe. Put the Y-pipe and cat away for future work. Do not cut the cat off at this time. Remove the O2 sensor from the passenger side of the y-pipe. The driver’s side is on the manifold. Remove the clip that holds the sensor wire to the block. You will need to stretch the wire a little to reach the new sensor location.
18) When you do cut the cat off, look at the end of the catalytic converter. It should be yellowish, with a bit of soot on it, and all the holes should be open. There should be no cracks or breakup. If there appears to be a problem, get a professional opinion. It is a violation of Federal law to 1) remove the catalyst, 2) replace a catalyst unless it is proven to be defective, or 3) change the number or location of the catalyst. I strongly recommend that you run a cat. If you want reduced back pressure, get a Random Technologies or Mor-Flo high flow replacement.
PLUG REMOVAL:
19) With the Y-pipe off, you can see the plugs and wires much better (except for #2 on the passenger side). JBA says to remove the back two on the driver’s side (#5, #7) and the back three on the passenger side (#4, #6, #8). I removed them all except #2, because I was putting in a new set of plugs. #2 has to come out from the top, and it requires removing the alternator, unless you are "plastic man".
20) You can leave the wires in the looms, and leave the metal heat shield on the wire to #7, but you might want to consider whether you will keep the same plug wire routing. If you are going to replace the wires, and reroute them, remove them now, and remove the metal heat shield.
ALTERNATOR REMOVAL:
OTHER REMOVALS:
23) There is a coolant temperature sensor on the driver’s side head, behind plug #1. Unplug it. Be careful when removing the manifolds or installing the headers. You can break this off.
24) Remove the plastic shroud from the flex connection in the steering shaft. You need to unclip the plastic band that goes around the middle of it. I’m not sure this is absolutely necessary, but it seemed like a good idea at the time.
25) Unscrew the A.I.R. tubes on each manifold. When they are loose, if you want to make extra room to work, remove the hose clamp on the vertical rubber hose, get a channel lock on the hose and twist it off. Do not damage the end of the hose. These tend to stick to the metal tubes, and are hard to break loose. Once loose, twist them back and forth and pull up. This will provide a lot more working room. Remember, test fit the screw threads into the headers NOW, to be sure the header threads aren’t clogged with the cerametallic coating.
DRIVER’S SIDE MANIFOLD REMOVAL:
26) Remove the bolts on the driver’s side manifold. They are all easy to reach from top and/or bottom. In general, the best access is gained with a good ratchet handle. I have the Craftsman ergonomic/professional, 3/8" with flex head. You may need a universal joint, a variety of extensions, and both regular and deep sockets (there is one stud on each side). I also recommend that you use 6-point sockets, rather than 12-point. Avoids rounding off the heads.
27) When the last bolt is out, the manifold will drop out the bottom (literally, drop, right on your head if you are under there).
PASSENGER SIDE MANIFOLD REMOVAL:
28) Move to the passenger side manifold. Remove the one bolt that holds the oil dipstick tube to the block, but do not pull the tube out yet. Remove the five bolts that hold the manifold on. This leaves the stud at the front most position. This stud is also used to hold the bottom of one of the alternator brackets. This may be easier to get out if you pull the alternator, just in case you were trying to avoid pulling it. Getting to the nut that holds the bracket to the stud is difficult. You can get a wrench on it and turn it about one-sixth of a turn at a time, but once it is loose, it can be taken off with your fingers. Similarly, it is hard to get at the stud. This corner of the engine compartment was designed by disciples of the Marquis de Sade!!!!
29) Remove the bolt that holds the EGR tube to the back/inside of the manifold. There is only one bolt, and the tube inserts about ½" into the manifold. Use a xx mm wrench. The front most manifold bolt is actually a stud. First you must remove the nut that holds the alternator bracket on. Then you need a 14mm deep socket to pull the stud out. SAVE THE STUD AND THE BLACK METAL SPACER. You will need to reuse them for the install.
30) The manifold will lift out from the top. Remove the O2 sensor and "discard" your manifold. There is a metal bracket at the bottom of the head. It has the clip that holds the wire for the O2 sensor. This bracket is not really needed any more, but it is almost impossible to remove. Leave it.
31) You can now remove the oil dipstick tube. It just slides up and out of the hole at the bottom of the block. BUT¼it is about 5" into that hole, and as you slide the tube up, it will start to hit on the fender well. Just keep pushing up from under the car. It will be necessary to bend the tube slightly (the portion coming out of the hole) to get it completely out. Put the bolt and the tube aside.
PREPARATION OF HEADS:
32) Scrape all the old gasket material off the heads. Mine had very little. I found that a Dremel with a wire brush worked very well. Also, a fine sandpaper (200 grit or higher) will work to get the material a scraper can’t get.
REPLACE SPARK PLUGS – PARTIAL:
33) If you are changing plugs, now is the time to pull the #2 plug.
34) Start replacing the spark plugs you remove, if you took them all out. On the driver’s side, you can put #1 and #3 in before the header goes in.
DRIVER’S SIDE HEADER INSTALL:
35) Then put the header in from the top. It will take some jiggling to get the bottom collector past the steering shaft, but it will fit. Try not to scratch the cerametallic coating. Let the header tilt up toward the cowl. This will allow you to get the #5 and #7 spark plugs in. Use anti-seize on all plugs. You will need to see when the best point is to put the wires back on the plugs. Again, I didn’t need to do it, so I can not help, but I think this is the right time.
36) Tilt the header down so it is level. Get a bolt, coat it with anti-seize, and insert it into the rear most hole (behind #7). Note that there are actually two bolt holes at the rear position and two at the front position. The OEM manifolds use the outermost holes, the headers use the innermost holes. The CopperSeal gaskets come with spring washers. I do not recommend the use of these washers. The JBA header flange as VERY thick. If you include the spring washer, you will end up with only a couple of threads in the head – not a good idea in aluminum. Without the washer, you pick up a couple more threads – much better. The thick flange on the headers really makes this washer unnecessary. Just get that end bolt started, but do not tighten it.
37) Move to the front most bolt hole (ahead of #1), and insert another bolt, just getting it started. Again, this is not the same hole the factory used. Now the CopperSeal gasket (or any other quality gasket with slotted end holes) will drop in from the top, hanging on the end bolts, in the proper position. Note that if your gasket has a sealing "bead" raised on the gasket, the bead should face the header flange. If you are using a composite (metal/fiber) gasket, you will need to coat both sides of the gasket with sealer, stick it to the face of the flange, then press the flange against the head, avoiding excessive movement. Do not let chunks of the sealer extend into the openings. The chunks will blow into the catalyst and plug it.
38) Insert the remaining bolts, coating each one with anti-seize. Pull them up evenly, working from the center to the ends. The spec for torquing them is 30-35 ft-lb (check-are these 3/8"-16?) using grade 8 bolts with oil, and 23 ft-lb using moly. I think the anti-seize most closely matches "moly", so I recommend the 23 ft-lb. This is easier said than done. You can only get a torque wrench on one or two of the bolts. My approach is, torque at least one of them, then get a "feel" for how tight this is – then tighten the rest by "feel" as best you can. You will probably find there are one or two bolts on each side that you can only get with a "stubby" 3/8" drive, or a box wrench. It is tight. With a small box wrench, you can not get enough leverage. If you have a small pipe (not longer than 12") slide it over the wrench, or get a large box wrench (7/8" or larger) and put the box over the first open-end wrench, and use it as a lever. With a 12" lever, you should apply no more than 23# of force.
39) Reconnect the temperature sensor on the head.
40) Check the fit of the A.I.R. connector. It should be exact, based on my experience. Do not install it right now. It will leave you more room for any forgotten items
PASSENGER SIDE HEADER INSTALL:
41) Move to the passenger side. The header will have to go in from the bottom, and it slides in fairly easily. Let it rest on the suspension/body, do not put any bolts in yet.
42) Go back up top, and put the spark plug back in #4. Use anti-seize.
43) Put the anti-seize coated stud you saved from the removal, with the spacer between the bolt head and the header flange, in the front most hole (in front of #2), leaving is loose.
44) Go back under the car and put in the #6 and #8 plugs. You need to jiggle the header and twist it a bit to get a straight shot at the plugs with your ratchet.
45) When the plugs are in, put a bolt in the rear most hole (behind #8). This can be done from the top or bottom – it’s tricky either way. Think about when to reconnect the plug wires.
46) Repeat the gasket installation, as noted in Item 37, above. The bolts on this side are the toughest part of the whole thing – or else I was just getting tired and ornery. But, these take a lot of flexible arm-twisting, and there is only one you can properly torque. The rest will need to be tightened by "feel".
47) Reconnect the EGR tube to the header. This is a bit of a reach problem, but not impossible. Tighten it well, since there is no gasket. I wonder how tight this seal really is?
48) Reinstall the oil dipstick tube. This can get UGLY. You need to reshape it a little to fit past the header tube (it is now inside, between the header and the engine). If you can get help, this is the time for it. One person needs to push down from the top, while the other guides it in from the bottom. When you finally wrestle it in, put the single bolt back in.
49) Reinstall the plastic shroud for the steering shaft. Reconnect the temperature sensor on the driver’s side head.
INSTALL O2 SENSORS:
50) Install the O2 sensors. If you are reusing the old ones, use the GM Sealant, (see list at top). If you have new sensors, read the packaging. My AC sensors were precoated with the proper material. Handle the sensors gently. Do not contaminate the sensing ends. They will screw in like a spark plug with a gasket. Use a 7/8" open end wrench, or get a "sensor socket", which has an opening for the wires. I have one, but the wrench worked fine. Torque spec is 28 – 34 ft-lb.
51) Reconnect the O2 sensors to the factory wiring. Get some long (11") nylon wire ties and pull the sensor wire up and away from the y-pipe and headers. On the driver’s side, I pulled the wire up against a factory harness near the top of the oil pan, and the clutch armored hydraulic tube. Not really a heat problem on this side, just trying to keep the wire from hanging down. On the passenger side, I found a factory harness wire over toward the shock tower and managed to get the tie on. This side is really critical, or you could have toasted sensor wires from the y-pipe.
PREPARE Y-PIPE:
INSTALL Y-PIPE:
53) Put sealer on the collector gasket (if using the paper type) and put it between the flanges, and try and get one bolt in the flange on each side. Then loosely put the rest of the bolts in. You need to jiggle things a bit here to get all six bolts in. When they are all in make sure everything is in the right place, nothing is hitting on anything. Then tighten the six collector bolts.
CUT CONVERTER OFF FACTORY Y-PIPE, AND INSTALL CAT:
54) Measure the distance between the end of the header y-pipe and the flange on the intermediate pipe for the catalytic converter. You will need to cut the converter off the factory y-pipe, leaving enough on the front end to insert into the new y-pipe.
55) You may have to loosen the entire rear exhaust section to make room to fit the cat in between the rear flange and the header collector. The hangers on the tailpipes are the main culprits. Insert the front of the cat into the collector. The cat is a little oval, and the header collector is round, so some gentle reshaping of the collector may be required.
56) You can then retighten the tailpipe supports and try and bolt up the rear flange. The flange will bolt up OK, but I found the cat was angled slightly downward, and only one of the cat support bolts would fit in the hole. You are going to have to go to a muffler shop to get the front end welded, and they will be able to fix things up.
57) I started the car with the cat stuck loose into the collector. Noisy!!. Eventually, I put some muffler sealer in the connection, wrapped it with muffler tape and held it together with some large (3-1/2") stainless worm clamps. This will keep you quiet until you can get to a shop.
58) When you go to the muffler shop, you might want to ask them to put a flange on the cat inlet, so you can use an "off-road" pipe for the strip (illegal of course, on the street!!)
CHECK EVERYTHING YOU DISCONNECTED
AFTERTHOUGHTS: