Gen II Header Prototype Update

[3100 MPFI]

I don't know about the crossover, but you better make sure there is a flex joint in the rear where it attaches to the rest of the exhaust. I broke the welds on my headers from not having a flexjoint in there. WAY too much stress.

[bracketracer]

Header Follow-up

Well, I will try to answer the questions in order.

We haven't come up with a final price yet, and won't until we make the next set. It shouldn't take as long for the 2nd set, and we plan to make some jigs and templates to easily repeat the process. Right now, I would say that an uncoated set would run somewhere between $600 & $750 (coating would be extra, and cost about $200 more thru JetHot).

No we do not have a flex pipe in the crossover (it has never made sense why one was there anyway). We weren't planning on having a flex pipe, but that isn't something that we can't change. Right now, we planned a ball flange at the bottom of the 2:1 collector which leaves some "wiggle room" for installation. I guess there is no reason why we can't mount a flex pipe somewhere behind that flange. Thanks for the heads-up 3100 MPFI!

I finally had a chance to test fit on Saturday. The good news is that the rear bank fits almost perfect. On my set, the crossover comes into contact with my shifter cables. Even with JetHot coating that won't work, so I will have to fabricate a heat shield. On our "production models" we will adjust this over to avoid cable contact. The crossover will need to be moved up about 1/4 to 1/2 inch, since there is a minor contact with the tranny mount. The front bank will need major adjustment. We will have to adjust the pipe that runs from the farthest port, because it interferes with the coil packs. There is also interference with the fan. It will be a tight squeeze, but we hope to fit them thru with the stock fan placement.

This is a question for any of you who currently run headers. Did you keep the stock fan, and stock placement, or did you do something different to give extra header space? My inquiring mind would like to know.

Thank You!

[torq455]

i wouldn't mind having the front headers go under the car. less under hood heat and more room.

[Guest]

No we do not have a flex pipe in the crossover (it has never made sense why one was there anyway). We weren't planning on having a flex pipe, but that isn't something that we can't change. Right now, we planned a ball flange at the bottom of the 2:1 collector which leaves some "wiggle room" for installation. I guess there is no reason why we can't mount a flex pipe somewhere behind that flange. Thanks for the heads-up 3100 MPFI!

The reason for the flex joint is due to expansion and contraction of the x-over (and other exhaust components) through heating and cooling. Without a flex joint, you can crack the headers or in some cases rip the studs or bolts out of the heads.

[bracketracer]

Hey Raven,
Thanks for the very important bit of info. My welder told me the exact same thing. Fortunately, the stock crossover appears to be 2", so I should be able to remove the flex joint from it, and incorporate it into the header crossover (which is also 2").

Last night I fit the rear bank, and discovered that we will need to slightly adjust the pipe heading up to the crossover. When turning the steering full to the left, there was some interference. That will be easy to fix. I just keep reminding myself that the headaches I get now, will help eliminate trouble with the "production" headers.

I do have one other question for those of you who have headers. What did you do with the metal coolant pipe that runs from the timing cover, across the front of the engine (around to the TB heater, which I bypassed), and on to the heater core at the firewall? This looks like it will need to be replaced by flexible line. Did any of you manage to run it with headers, or did you just reroute it? Just curious.

[torq455]

didn't think you had to do anything with that.

[Superdave]

Hey Raven,
Thanks for the very important bit of info. My welder told me the exact same thing. Fortunately, the stock crossover appears to be 2", so I should be able to remove the flex joint from it, and incorporate it into the header crossover (which is also 2").

Last night I fit the rear bank, and discovered that we will need to slightly adjust the pipe heading up to the crossover. When turning the steering full to the left, there was some interference. That will be easy to fix. I just keep reminding myself that the headaches I get now, will help eliminate trouble with the "production" headers.

I do have one other question for those of you who have headers. What did you do with the metal coolant pipe that runs from the timing cover, across the front of the engine (around to the TB heater, which I bypassed), and on to the heater core at the firewall? This looks like it will need to be replaced by flexible line. Did any of you manage to run it with headers, or did you just reroute it? Just curious.

On both sets of longtubes i made i ended up adjusting that line, just cut off what would interfear, weld the flared piece back on and run flex line...


Mine is bypassed as well.

[3400-95-Modified]

The reason for the flex joint is due to expansion and contraction of the x-over (and other exhaust components) through heating and cooling. Without a flex joint, you can crack the headers or in some cases rip the studs or bolts out of the heads.

With that responce i'm kind of suprised that S&S doesnt have flex on their crossover pipe... Kinda too late for me to do anything about it now unless I were to take the front header out again.

I have heard of many people with the S&S headers on the GA and they arent having any issues with it, so I guess it can't be that big of a deal.

[Guest]

With that responce i'm kind of suprised that S&S doesnt have flex on their crossover pipe... Kinda too late for me to do anything about it now unless I were to take the front header out again.

I have heard of many people with the S&S headers on the GA and they arent having any issues with it, so I guess it can't be that big of a deal.

I believe S&S uses a ball coupling though, correct? Where the front header bolts to the rear header/Y-pipe, is a joint that will swivel and "flex", correct?

This joint/coupling will allow for some expansion and contraction, but I still prefer a bellows style fex joint in addition to the ball coupling. Look at the stock 660 FWD set-up, where the crossover is only about 18" long (off the top of my head) and has two ball joints AND a bellows flex joint.

[Superdave]

on the "shorty" set i built to sell i actually cut the flex piece out of a gen3 crossover and used it...

[bracketracer]

Yesterday I went over to my buddy's house, and we "re-engineered" the headers. The set I posted pictures of had clearence issues in front (both coils and fan shroud), slightly in the crossover (with the tranny mount), and in the rear (with steering arms in full right turn). We also incorporated the flex joint from my stock crossover into my crossover (much like Superdave did), since I couldn't find the proper sized flex joint or pipe thru regular sources fast enough. I managed to pull my original engine and tranny from the car yesterday, and we installed and tested these ones on it (I also took careful measurements of distances to fan shroud, firewall, etc). My buddy will do the "finish welding" and clean-up this week, and then they will be ready to ship to JetHot for coating. Our "production sets" will be different to make them more "user friendly." The set I have now will require replacing the front heater hose with flex hose, as well as the upper radiator hose being flex hose or a different production version, and I don't think I will be able to fit the Z-24 filter canister. I will end up doing a warm-air intake at first, and then build a box for cold-air from the hood later. I'll post more pics when I can.

[torq455]

any updates?

[SappySE107]

Yeah, I gotta fix the heads Looks like the exhaust springs were 1.6" install height and that didn't work too well for the LS6 springs and that cam. So I am going to cut the pockets down and give it some room to work with. Ill have the heads next week to see why they are like that. Then he can test out the headers

[bracketracer]

Header Update

I talked to my welder last night. He has the front header and crossover completed and will probably drop them off tonight. He is hoping to have the rear header done by this weekend.

The issues that Ben mentioned are a "mixed blessing." If my motor was done and we had dropped it in already, I would have had to run the headers uncoated. This made me a little nervous due to proximity to coils, hoses (radiator and heater), and shifter cables. Now I will have time to get them coated by JetHot before installation. That will cut down on heat exchange to nearby components, and should help with performance slightly.

Once we have my Sunbird back together and tuned with the headers on, we plan to get our first "production set" done. We have already learned some useful "lessons" that we will incorporate in those future sets.

I will have to let Ben take a look at my headers when we do tuning. If he likes what he sees and wants to offer them thru the 60degreeStore that would be fine by me. Remember, these will be designed initially for a J-Body with a Gen II/5-speed for sure, and probably for a Gen III/5-speed as well (the only real change would be the flanges, I believe). We may need a deposit of some type to help offset cost of some of the components up front, but we want to turn them around as fast as we can. I can realistically see us being ready to "production sets" by October (maybe sooner if things fall into place). This won't help folks this race season, but it will provide for a winter project so they will be ready next year!

I will post more pictures of the finished prototype set off the car and installed once they are in.

[whitelightnin04MC]

S&S uses a donut style gasket on the crossover.