So after getting my motor back together I'm trying to tune the carbs. One of the tricks I found on google is to hook up a vacuum to your exhaust and spray the fittings with soapy water to find leaks. Well I did it and all 4 header tubes to the heads make bubbles. So I started to dismantle the exhaust and put it all back together. This time double checking the trueness of the headers AND annealing the gaskets, which I did not do the first time. Bolt it all back up, torque to spec and bubbles still They are a tight fit getting on meaning I have to wrestle them onto the exhaust studs but this is ridiculous. Any other tricks of the trade I missed? Do I need to bend the stud loops so that the exhaust slides right up against the gaskets without fighting it back and forth, left and right?

If the flanges and tubes are properly welded they should fall into place. Sounds as if the flanges are not parallel to the ports. If all of them are out of kilter you have a mess on your hands not easily remedied. Whoever made the system needs to try again. Send it back.

Getting the heat exchangers to seal is tricky with SSI or stock. Pull hem off and look at the sealing rings to see that they were seated properly. Flatten the tops of the flanges on the heat exchangers with a piece of flat stock and 180 grit sand paper. Anneal the copper rings. You can reuse them if you flatten and anneal them. Carefully install them checking that the sealing rings do not stick out on one side more than the other. gradually tighten the four nuts to pull them up evenly.
I have heard the SSI quality is not as god as when they were made by SSI in the US. Who did you buy them through ?

They came on the car, I figured they were OEM 2.0.

When John Daniels ran SSI they were always perfect!

bolt them to the heads first, while leaving only one bolt lose and yet holding up the rear of the HE.
Get them torqued, then do that again.
Then, add the muffler, but never put the weight of the muffler on the HE.
So, hold that up with a floor jack, and tighten up all the bolts together, but never stress the HE.
then you can let down the flor jack.

rich

Rich - I don't follow.

There are 4 nuts not bolts. I don't have any weight on it yet as I am just checking for leaks. They are also pretty tough to get into place. A lot of shifting back and forth using a nut on one stud to make sure it doesn't fall off while shifting and pushing. I do think the alignment of the loops are off.

Did you replace the exhaust studs? If yes, are you absolutely 100% certain they are the exact same size as what came off the car?

When I did mine, we replaced the studs with a size that is correct for my motor in stock form. Little did we know I actually have bus heads on the car. The studs for the bus heads are a little bit different in length and diameter. So when I tried to torque down the nuts, they would actually “bottom out” on the threaded part of the studs. I hope this makes sense.

While i didn't bubble check them as installed, i was careful to place the cu seals in the heads and fit and torque the 4 bolts. i was running the engine in on my cheapie test rig in the garage and ran the engine to do a cam break-in and do basic carb tuning. I then checked the exhaust stud nots and found several to be well under torqued. i assume that a few heat cycles evens out alignment, so re-torquing them seems to provide leak free fitment. i will be running the engine a few more cycles before installing and will again re-torque the exhaust studs

Bring all 4 nuts to just off snug and tighten in an X pattern in 5LB of torque increments over a few stages. Bringing one up fully tight can cock the HEs and build in a leak or leaks.

Check for bent broken mounting ears, straighten and weld them if needed.
Use a heavy washer under the nut to even the load on the ear and resist the urge to over torque the nuts.
Over torquing will bend the ears.

I doubt you will ever get a 100% perfect soap test seal, carbon will plug very minor leaks.

Some members have resorted to using orange high temp RTV, personally I don't care for this but letting you know as an option.

While the soap test will work statically, what I've found...and Mark has more experience than I...but when the heads heat up and the gaskets are annealed, they will have a tendency to seal when they expand. The high temp copper sealant keeps them from leaking until the heat soak does on the copper gaskets.

I did a thread on this and they haven't ever leaked in 5 years of heat cycling, and I've driven my car in temps about 110 degrees.

I use this on motorcycle exhaust systems. They come apart easier. It does have some sealing qualities too.

Click to view attachment

2 of the ears are bent. On one that is bent has cracked the bottom part of the weld. I have a welder but have never welded. Is SS any different? It is a mig welder and I bet I need a tig. I could try to heat it up with a torch and bend it. Will thwart work? I also think I will fit them on the old heads to ensure proper fitment.

The MIG weld area will rust but it will work. Practice on scrap first till you can get a good bead, on similar thick steel.

SS TIG would be better in the long run.

Even if you use SS wire? Looks like small spools are fairly cheap. I've been curious about welding SS myself.

Never tried it because i have TIG, I'd still get some scrap SS and practice first.

I've done a couple of exhaust systems w/ SS using my mig. Different spool and gas mixture. If you have another tank fine, otherwise you can easily weld it with 75/25 gas. I think it welds better than aluminized steel or other steel.

SSI's are notorious for having problems sealing to the head, broken mounting tabs, and uneven flanges.

The sealing surface is roughly 1/3 that of stock HE's. Stock boxes have a larger flange that's welded (outside of the heat box) to the exhaust tubing.

SSI just formed the tubing oval, but did not make a proper flange for exhaust sealing. Compounding this problem is the fact that you'll often find the sealing surfaces on SSI heater boxes are not level, in addition to marginally sufficient mounting tabs, that as you know get over torqued and detatch. The sealing surface can be checked by putting a straight edge across the sealing surfaces.

Most of the SSI 914 heater boxes I've seen require leveling of the sealing surfaces. I use a very large file that will span the distance of both tubes. I mark the surfaces with a marker and file until level, which takes a while and is hard on the file. I would not attempt this with any sort of power hand tool.

over torquing is a very efficient way of distorting or tearing the ears off. A light touch for the file work. After a few passes you'll see the problem spots. The 'bastard' file needs to be pretty big.

Make certain the mounting ear is not bottoming out on the head. The top of the pipe needs to press on the copper gasket. If the ear is too close to the end, it can bottom out first preventing a tight seal