Topic: Exhaust help cb550

[work9to5]

Hi guys, I picked up 4 reverse cone mufflers off CL for really cheap. I decided I want to mount them on a cb550 project I'm working to mock the oem exhaust. I realized when I bought them that they wouldn't be a direct mount unfortunately. I'm using stock headers 1.25" od. The exhausts have a 1.72" id. They came with 3 reducers. I bought 4 "exhaust reducers" that go from 1.25" to 1.5" and slid in one of the reducers and they fit pretty close. Here's pics of the set up. Here's my question. On the header side of this reducer they are not super tight on headers 2/3 (1/4 are tighter because of the angle of header). How should I clamp/seal these suckers?!?

Should I?
1.) get a clamp and just tighten it till the metal constricts around header
2.) cut a slit in the reducer and then clamp over it. The slit would help the metal form around the header better
3.) weld the reducers directly onto the headers

[carnivorous chicken]

or 4.) You can get a roll of exhaust repair/seal tape at an auto parts store and wrap it around the header until the reducer fits more snugly.

[work9to5]

Didn't even think about the tape stuff. Havnt used it before. It needs to be kind of a structural hold though. Might use the tape and clamps together.

[carnivorous chicken]

There ya go. Some of the exhaust tape will essentially bake with head, bake hard, and make a good seal. Hard to tell from the pictures, but you are going to have a rear mount as well, correct? You'll need one...

[work9to5]

Yeah the rear mount is on in the pic. It's hid behind the mufflers. I used one of the chrome mounts and drilled a hole to mount the other exhaust in it as well. The pipes are zipped to the frame in the pic cause I didn't wat them shifting on me or messing with the head bolts.

I've actually never seen an original 550 4 into 4 exhaust in person. So I'm kinda really curious how they sat on the bike. Kind of amazing that ive never seen one lol, considering I own three of them.

[Camrector]

Loving the way your pipes sit Chris!

[calj737]

Your best bet is to weld the parts together. Though when you do, the finish will be damage in that area, and the pipes must be very clean inside and out. I would not expect tape and sealer to survive long without cracking or leaking due to the stress on the pipe in that area and the vibration.

Also, changes in diameters of the tubing will effect the performance of the system scavenging the gases, especially if all four tubes are not equally sized.

[RAFster122s]

Welding is the best solution as Calj has said...
If you have a speed shop used by custom car, hot rod builders in your area you should call them and ask for recommendations for good exhaust shops that do custom work.  They are likely to be able to transition the pipes the way you want them with a steel that is better quality and they can weld up your pipes.  They can tack them together on the bike after fitting the pipes transition pieces and shrink or stretch the pipe as needed.

Stock pipes are both ending at same length on the bike and they are stacked with a transition pipe between both mufflers with a rubber coupler near the end of the cans. One of the pipes links to the #2 or #3 and the other connects to #1 or #4 pipe and they are angled slightly which gives them a slight stagger when viewed from behind.  There will be a good photo on the cb550 about section of this site backing up, not part of the forums but the sohc4.com area.  Motorera.com has stock bike side views as well.
Look up Sohron's thread about restoring his '74, should have excellent photos there.
 From the side they appear stacked pretty well with the ends ending up side by side.  The front of the pipes relocate to accommodate the header pipes some.  So, a custom reducer could also adjust the pipes connection for #2 & #3 so the mufflers both end at the same point.  The way you have them has a nice angle to the end but you are sacrificing some clearance I believe now that a custom pipe could regain at the expense of moving the pipes higher changing the visual.
Do you want looks or function, or a mix of both?  Question will be, how wide will your chicken strips be?
On the street I would hope they are wider than a track bike.

David

[Scott S]

 Places like AutoZone, etc., sell reducers. It'll be a 3-4" long piece of pipe that is smaller on one end. It'll be stepped, sort of. I've seen people use those.

 For example: https://www.oreillyauto.com/shop/exhaust-parts-16469/adapters---reducers-16675/straight-reducing-adapters-18831

[Stev-o]

+1 welding but if the parts are chrome, the finish will be damaged.

[strynboen]

hvy do you,have a oil tank ..? is it a 750 exh system..you try to fix on a 550

[work9to5]

So I decided welding them is my best option. Going to weld the headers directly to the reducers. They're different metals (stainless to mild) but did a ton of reading last night and apparently it's possible. Couldn't find much on how good penetration is but I'm going to try it for now. If it does gal down the road I'm planning on building a straight 4 into 4 off the headers in the same configuration. I'm aware of sacvenging issues but with the mufflers being a different diameter than the headers there's really no way to avoid it at this point. I looked at a bunch of pics last night and finally found a rear view of oem pipes. My lay out is pretty close so I'm satisfied for now. I think they look lower than stock in the pics because the bike is lower than stock. (Gsxr front, 17" front, 16" rear) and my pegs will contact long before my exhaust. It's just going to be an everyday bike, non race. Just building her because I plan on selling one of my other 550s possibly.

I'll post a pic of the reducers I'm using. And the weld process in future posts. Also a back end pic.

Yeah that's an "oil tank". I fabbed it to use as my battery box. It holds my key, solenoid, battery, fuse box currently. It's pretty neat, but definitely not oem hadn't seen it done except on xs bobber builds before. And wanted to try something different.

[strynboen]

nice idea...and you can easy veld mild steel and rustfree steel together..have done it....just ned to paint the.. weld areia..

[calj737]

nice idea...and you can easy veld mild steel and rustfree steel together..have done it....just ned to paint the.. weld areia..

Use 309/312 stainless and forget the paint.

[strynboen]

it vill mix up in the veld..so rust vill slov grov..but just paint the veld only.. then it holds fine up..

[work9to5]

So that's done! Was surprised how much penatration through mild to stainless I was able to get. I started by spot welding all 4 while still on the bike. I was worried about flex so threw down pretty hefty tacks to start. Then removed the exhausts one by one. Removed mufflers and started welding. Welds weren't the prettiest. I was out of position, on my garage floor and dealing with a pipe that doesn't lay flat. So that was fun! I was able to get good coverage with no burn through and good heat transfer. They are solid and air tight. Putting them back on was the toughest part. And getting them into the same stance as they were with new crush washers. Took forever. But it worked and I can check that off the list.

I am aware that I'll have to cover/coat the weld area in the future or it'll rust out. Im in Nevada currently and am going to wait till after she's up running.

Now onto the battery "box" and inner mounts.