Tubular header to ss exhaust pipe

[lbcfan]

This seems to be a problem.

I'm reusing a tubular header that I've had for years. It has a 1-1/2" female connection to the pipe.

My old exhaust pipe was 1-1/2" OD (mild steel), but a while ago, anticipating the rebuild, I purchased a Bell ss exhaust for the 948 that I had at the time. The thinwall tube is only 1-1/4" OD. I've done some research and I'm confident that the tube and straight muffler will give me the low enough backpressure and high velocity that will work well, even for a 1275. I've checked and the standard 1275 steel exhaust is 1-3/8" OD.

I also have a motorcycle exhaust set of bushings that gets me down to 1-3/8" ID on the header.

Problem is I cannot find a way to bridge the last 1/8" size difference to get to the 1-1/4" OD on the pipe. I've searched the UK sources and called local exhaust and motorcycle shops, and nothing seems to be available. By the way, I Emailed Bell and have not received a response. Disappointing...

Does anyone know a custom exhaust shop that could fabricate an adapter? I cannot be the only one to have run into this.

I would revert to the 1275 header, but the Bell front pipe is shaped for the 948 manifold.

Thanks for any sources,

Michael

 

[aeronca65t]

Try Here?

 

[lbcfan]

aeronca-

Thanks- close, but the 1-1/4" OD is actually too small.

Maybe I can offer a prize- all the unusable and extra parts that I will have left over from the restoration. The winner will have to send a truck...

 

[Gerard]

Michael,

Any decent muffler shop should be able to make this up for you. The usually have the machines to stretch or shrink the pipes. All you need is a short coupling.

 

[Rut]

Michael, Gerard hit the nail on the head. My muffler shop 'sweged' the muffler to fit the exhaust pipe, no adapter needed. They can do it for a slip fit or weld it.
Rut

 

[lbcfan]

Gerard-

I'm not sure what universe you guys live in. I read about all of these friendly local glass and muffler shops that look for unusual challenges. Around here (NJ) I have not had that luck.

I have called around. If it isn't a stock size, no-one is interested. I had bought an expander months ago- supposed to start at 1-1/8, but it won't fit into the pipe. I was concerned about stretching the thinwall ss anyway. It joined my pile of unused or never-will-be-used parts and tools.

If you know a shop in CA I would call them and have it shipped. Any source would be appreciated.

Regards,

Michael

 

[JPSmit]

Michael, not sure where you are in NJ but, I googled "custom exhaust" +NJ and got a number of hits. You are correct that most shops only care about what they have on the shelf but, they are out there.
Custom shops in NJ

 

[Gerard]

Michael,

I think as JP suggested already, you want to avoid the "big box" stores and try some custom or at least small. independent shops. In my "universe", there are places I can walk into like Sanderson Headers, but I use a small muffler shop in town for this sort of thing if I can't find an off the shelf reducer.

 

[lbcfan]

JP-

I've called a couple, including Mufflex in Camden. No-one goes down to 1-1/4". The best suggestion is to weld a larger pipe onto the end of the Bell pipe. That may be the way I have to go.

I've also found some slip-on chrome pencil exhaust tips in the UK that are meant to fit over the 1-1/4" pipe. If I cut one up it might create a bushing from 1-1/4" to 1/-3/8", which is what I need.

I know in the scheme of things that this is a very minor issue. I'll get it resolved.

Thanks,

Michael

 

[JPSmit]

Michael, have you considered getting a flange instead? wouldn't be perfect flow but it is another option & would be removable.

 

[lbcfan]

Problem solved. Found an adapter that has a 1-1/2" ID and 1-3/8" OD, at Advance Auto of all places. Expanded the 1-3/8" end slightly so that the 1-1/4" ss pipe "slipped" in, and butted the 1-1/2" adapter end to the header, with a 1-1/2" short pipe connecting inside. Looks streamlined and flow is smooth.

Thanks.

 

[rkep01]

Congratulations! I know the great feeling of accomplishment when you persevere and achieve your goal. Remember what Thomas Edison said - "Invention is 10% inspiration and 90% perspiration".

 

[lbcfan]

Miracles enter into it. After searching the web for hours I found the little sucker laying in a bin at the store.$3 for the adapter and $30 for 3 chrome motorcycle exhaust clamps. Seems right...