Exhaust sound

[frozenveinz]

Is there any way to make a two stroke have an exhaust that doesn't sound like the offspring of a chainsaw and a hive of bumblebees? Maybe like, put put put? Not YEAANNNN YEAANNNN YEAANNNN?

[2door]

Not much. The laws of physics will only let you do just so much to change the sound of a single cylinder 2 stroke engine. Expansion chambers, megaphones, even motorcycle type mufflers are still going to have that characteristic sound. A longer pipe will soften the crack and ring-a-ding noise but because of the inherent high RPMs you'll still know it's a 2 stroker.
Tom

[frozenveinz]

I see. But does that mean a two stroke at 5k rpm sounds like a four at 10k? Or does the valved exhaust of a four produce a different sound?

[2door]

That's probably not a bad comparison except 10K for a normal 4 stroke would be really pushing it.
The fact that you have twice the number of compression/power strokes with a 2 cycle verses a 4 explains the sound difference. Your 5K to 10K concept is valid.

There is a difference in the restrictions of the exhaust path with valves (4 stroke) as opposed to an open exhaust port (2 stroke) and it undoubtedly accounts for some difference in the noise they make.

Tom

[Kiwegapawa]

Hi 2Door, I got a question about exhaust sound in the opposite direction of what frozenveinz is asking. Looking to quite the engine beyond that of what a stock muffler does. Do you have any recommendations of type and brand. Plus maybe a ratio of quiteness to loss in hp? In this I will be looking to lengthen the exhaust pipe to reach the rear of a Stretch Cruiser Z2. Which I understand will have some effect on the produced sound also. Should mention, I'm working with a HF Pedator 6.5.

[2door]

Kiwa,
Lenghtening the pipe will alter the sound. I use 3/4" EMT, electrical conduit, to build my pipes and weld the stock muffler out on the end. They're quiet and seem to have little to no effect on power. I like to have the muffler behind me so that puts it back near the rear wheel. You can check my profile/album for some photos of my pipes.
I never use the catalytic converter type of muffler. Just the chrome standard one that comes with most of the earlier kits. I use a TIG welder but if you're good with a MIG, that will also work.
Tom

[Kiwegapawa]

You respond faster than I can read. Thank you buddy! I was just reading deeper into these threads under Carburators and Exhaust. This where I'd just caught your further notes on which you are telling me here. Loved the outcome of your Stainless Steel. Also caught the point of the use of glass packs back in there. This though I hadn't dug further into the use of glass packs and setting them up. Stopped and ordered an electric start kit match up to the gx200, for the Pedator 6.5 hp. This when my notice of your responses to me came in.

Not sure the the difference would prove unsurmountable? But I still chip slag. I've been electric arc welding for 43 years now. Never did learn to Tig or Mig. Until joining this forum over a year ago, I'd only observed it being used around me. But until joining here, I hadn't read the finer points on them. But now have all the PDF's on either. Till Harbor Frieght, never thought they were affordable. But I have an Arc welder here, along with cutting torches and know how to cut and braze also very well. If you know a reason why arc welding would not surfice, I'd like to know more?

With 3/4" EMT it will shrink the exhaust port size. As it is 1 inch ID. Though the stock muffler is already shrinking it, as it's 5/8 ID, 7/8 OD. I believe I saw it mentioned in the thread where I saw your stainless exhaust. Someone mentioned 1 inch of the same stainless? Matter of fact, in that thread you'd mention and showed pictures of both types you'd used. One had a homemade flange, that one was other than stainless. But the stainless one I cannot get around, as it was quality in excellence in workmanship. Superior to retail for sure! Exactly what I'm shooting for. Hopefully I'll make it there. Either way, other than possibly using the flange off the Stock muffler ~ is going bye, bye. Looking for something quieter and eye pleasing.


I can draw a tight bead in a flawless flow. But around an object of course you have to stop adjust the object, but even still. This along with slag removal and clean up and buffing? I have no problem with spending the extra time. If one thing I got, is time. Like most I've seen here at the forum of the ole timers like myself, I got the dremel 4000. With about 300 to 400 different attachments. Including all the diamond point bits, drill press, and rotary cabled pencil point attachment. For the bigger jobs, I got a Skil Pro variable speed and reversing 3/8ths high speed drill. With maybe as many attachments as the dremel. Disc Sanders, belt sander, all but need to get a new bench vise. Otherwise I believe I'm pretty well stocked up on needed tools.

I have a very large electrical and plumbing supply house about five blocks away from me. Very close and convenient. Or six blocks the other way an Ace Hardware. So it seems your work on the stainless has won me over, lock, stock and barrel!

[Ibedayank]

Kiwegapawa
if you want it quite you need a real muffler not the tiny thing for a b&s
like this one



http://www.ebay.com/itm/JMSTAR-Eagle...214#vi-content

[Kiwegapawa]

Thank you Ibedayank. As it was too late to act today on your help. I was able to get a contact number from eBay to the seller. Always amazes me to find those parts for sale, there photo'ed displayed in all their glory, without any specification.

You know, like length, diameter, ID err OD. But, I'll be calling them Monday to find out the specifics. As what eBay had listed for the seller, they are only open on the weekdays.

Again, thank you very much for the heads up.


Dang, Looks like I got my Crosses Wired. There in miss read what you said. That's the one "NOT" to get! LoL,, Opp's, LoL , Welcome to my world!

[Ibedayank]

not a small can thats for sure