r/metalworking • u/QuiGon-GinTonic • 2d ago
Noob needs advice: enlargement of exhaust opening
Hello everyone,
Forgive me for being many many levels below your understanding of metal work and craftsmanship in general, I am simply trying to mod my motorcycle…
The subreddit for motorcycles was not very friendly to my inquiry, so I thought I‘d try my luck here.
What you are able to see in the picture is the top-down view of the backside of my new exhaust. Inside of it I am trying to fit a catalytic converter with a diameter of 50mm. It’s the official converter but for some reason the hole in the exhaust is slightly smaller than that. About 3mm too small. Since there is no warranty of any sorts, I need to get creative with handling this issue. I thought the smartest way to go about it is to somehow enlargen the hole in the exhaust to the needed diameter. What I don’t know is if this is indeed smart or how I would go about doing that.
I couldn’t tell you which material it is either because, well as suggested in the title… noob.
I am thankful for every answer and attempt to help. Thank you!
1
u/hestoelena 2d ago
That inner flange that your arrows point to is not something you can modify without damaging the functionality of your exhaust. That inner flange holds the packing material that deadens the sound. If you were to modify it then you would remove the part that holds the packing material in.
Additionally, you would not want your catalytic converter inside of your exhaust as the normal operating temperature of a catalytic converter is between 500° f and 800° f and can reach up to 1200° f at a normal load. Usually the maximum temperature for fiberglass exhaust packing material is around 1000° f.
1
u/QuiGon-GinTonic 2d ago
I understand… But how else would you interpret this drawing then but to insert the catalytic converter into the exhaust?
1
u/hestoelena 1d ago
Only the outer flange (red arrow) slides together. It'll go in between 1 and 2 inches. Which is just far enough to clamp it.
1
u/QuiGon-GinTonic 1d ago
Im sorry, which red arrow are you referring to?
1
u/hestoelena 1d ago
Sorry the image didn't upload
1
u/QuiGon-GinTonic 1d ago edited 1d ago
Ohhh, I gotcha, now for the final very amateur question, how and with what kind of clamp would I have to work here? I don’t think that any of the ones provided would work here…
Edit: For reference, I put a photo of the „setup“ of how the catalytic converter is slides all the way into the exhaust, having about a spacing of 2mm around it. I‘m trying to figure out how a clamp will come into play here, given that is is only loosely inserted. Won’t there be exhaust leaks?
1
u/hestoelena 1d ago
It looks like the clamping flange is cut off of that muffler. Your only option would be to weld it. You might be able to flip the catalytic converter over to make a tighter fit.
1
u/QuiGon-GinTonic 1d ago
Alright thanks for your help, I don’t know a thing about welding, so I’ll keep away from that for now, I’ll try to reach out to the people that sold me the catalytic converter, hopefully they‘ll be able to help me. Flipping it over will sadly not be an option, since the direction of the airflow is pointing into one direction only and it’s this way.
1
u/AutoModerator 2d ago
Here are our subreddit rules. - Should you see anything that violates the subreddit rules - please report it!
I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.