When I built my lakes headers I also built my mufflers. Kinda tuff to buy mufflers to fit. I used a thread from here on the HAMB for a how too.
Maybe Rui dosen't have a muffler shop just around the corner like a lot of us... he lives in the north of Portugal...he has to make stuff........like real hot rodders do.......
I bought a set of Porters for my Y block Rams horn exhaust and looking at them, realized I don't know much about mufflers. They have a heavy spring that goes all the way through a straight tube, and I guess the packing material is stuffed around the other side and fills the rest. But there's no resistance to the exhaust that I can see. Anyway they sound fine.
I made a pair of mufflers for my 59 Ford Wagon, blatantly copying this design here: http://www.spintechmufflers.com/superior-design/info_5.html Made them low profile, ( 2 1/2 inches thick), and made them "quite voluminous" for the existing space under floor. Made them from stainless, and used "V-band" flanges on inlet and outlets. They worked well, and sounded great, and became un-noticeable on the highway @ the 60-80 mph. range!
I made a set but they sounded no better than the smith (smitty) steel packed mufflers. I was fun building them.
I don't see why guy are being hard on the guy. He built something cool for cheap, and he wants to share. I can get behind that. It would be pretty fun to mess around and figure out what changes the sound, etc.
I can't find the thread it was before this new format. Basically I had cone shaped lakes headers (I built) measure the id of the cone at the small end then measure the large end. I made two washers with an id of 1.5" the other od was the cone big and little ends. I then used some 1.5 exhaust tubing and welded the washers too it. I then used an air chisel with a punch type tool to poke holes in the 1.5" tubing . Your punching will leave a ragged holes which will disrupt the exhaust gasses .
there flow is disrupted and you can add steel wool around the 1 1/2" tubing if you want too quite it a little.
It is possible that I'm thinking too much here but sound does not like to change directions. Send it south then north and then south and it will be greatly reduced.
Did the 'punches' face into the exhaust or point away? If you had to make a new set, what would you do different?
We used to make them for the stock cars. 2 #10 drink cans brazed in line with a piece of straight pipe through it. Paint it flat black and the tech inspectors never gave it another look.