Late Chief exhaust system advice needed

[cdf6333]

I have a 1946 chief with the 1 piece exhaust. I did make one years ago which looks great but the bike is much too loud and backfires a lot. I 'm thinking of getting a 1948-51 exhaust to use for my local riding and keep the one piece for showing.
The muffler I made has just an expansion chamber, virtually a straight pipe. Does anyone make one that actually creates back pressure? I think the bike would run a lot better at low speeds too with more back pressure.

[T. Cotten]

I don't know what "back pressure" is, Bob!

But I had great luck on different 'systems' using perforated sheet metal, rolled into a springy tube that fits into the pipe, held with a screw or pop-rivet. Cutting between holes made triangular ears that could be bent into the flow as little or as much as you wish.

Tuneable!

....Cotten
PS: Tube version on left worked in straight sections of pipe, whereas the two on the right worked well at the very end of opened-up 'mufflers'.
And they stopped a billy-club inspection, back when badge-less motorcyclists weren't kewl.

PPS: Helluva lot cheaper than a new system that might fit maybe.
But backfiring is usually an exhaust leak near the port, and these would only be a band-aid.

[pisten-bully]

You can get Greer's header and muffler/tail pipe parts in bare steel, fit and weld into the one piece system, and then have them chromed. Greer's muffler is baffled so it's quiet. It'll set you back a few $$$, finding someone who will chrome a piece that long and for use in an exhaust system (not a chrome expert here, but you don't want it to turn blue) but it will set your bike apart from the many you see with 2-piece systems!

[exeric]

It'll set you back a few $$$, finding someone who will chrome a piece that long and for use in an exhaust system (not a chrome expert here, but you don't want it to turn blue) but it will set your bike apart from the many you see with 2-piece systems!

I had that problem with the welded muffler, and rear header pipe on my '40 Chief. Platers wouldn't touch it because it was too long, and they said it would be too contaminated to put in their tanks because it had been run on the bike. I couldn't really blame them, but chrome would have looked good.

my indian.jpg

[TH47Indy]

You can get Greer's header and muffler/tail pipe parts in bare steel, fit and weld into the one piece system, and then have them chromed. Greer's muffler is baffled so it's quiet. It'll set you back a few $$$, finding someone who will chrome a piece that long and for use in an exhaust system (not a chrome expert here, but you don't want it to turn blue) but it will set your bike apart from the many you see with 2-piece systems!

I have the setup that Piston Bully is describing and just received the one piece back from the platers. It is harder to find someone with the big tanks, but if it’s a new never used exhaust it shouldn’t be a problem with contaminating their tanks.
I believe that that the exhaust was polished and the copper plating was skipped to keeep the pipe from turning blue.
Still in build mode, so haven’t run it yet but does look great.

[PRG]

Howdy chaps,

Nearly all bluing occurs in the first minutes an exhaust is used, any later can generally be traced to a lean mixture or retarded ignition. Sharp radius (like a Velocette Venom Thruxton header), tube proximity to exhaust valve on flatheads, thin tubing material or poor plating aside, one can nearly eliminate this possibility by applying a sacrificial barrier to initially burn off and be replaced by carbon.

Thoroughly clean the inside of the exhaust with a degreaser, heat inside with hair dryer and repeatedly apply BBQ grill or header paint on coats so heavy that it runs, rotate pipe to evenly distribute while applying heat. Treated header on my 346 thusly many years ago with no significant change in plating.

[cdf6333]

Hey Harry
I'm the one that sent you the pics of my 46 when you were making your exhaust. My Greers wasn't baffled, just expansion chambered.

And I'm not looking to Chrome one, I made one and had it plated by Pauls a few years ago. It's just much too loud and affects low speed performance. Losing back pressure, like it seems all Harley guys do by removing the mufflers for straight pipes, only helps top end RPMS, it hurts torque and low speed use.

Cotton's idea is close.

901-483_A.jpg

I guess I'll try this Vance and Hines Baffle. It actually stops the exhaust- forcing it around the outside of the baffle to escape.

[pisten-bully]

Hey Harry
I'm the one that sent you the pics of my 46 when you were making your exhaust. My Greers wasn't baffled, just expansion chambered.

I knew that was you Bob! (....just puttin' a plug in for Greer's!). Mine is baffled....hmmm. Sent you a PM, too!

[cdf6333]

I knew that was you Bob! (....just puttin' a plug in for Greer's!). Mine is baffled....hmmm. Sent you a PM, too!

BTW, an expansion chamber is when the exhaust goes straight thru the muffler, just an inner pipe with holes in it and usually wrapped in g fiberglass, hence the name Glass Packs for the 50's and 60's hot rods.

A muffler actually stops the exhaust, in a car it makes an S turn ( 2 u turns) -- before exiting. This gives back pressure and can be very quiet.

I want the quietest muffler I can find, I'll keep the one piece just for future shows. I hate riding a loud bike. Has anyone tried one of Gary Starks's Nelson Mufflers? PM me if you have any info on one

Thanks
Bob Courboin