Show off your muffler mods

[RI Chevy]

Ok..be that way .[emoji2957]

 

[big t double]

no

Haha

 

[Sawrain]

Rescued a neglected 036, runs better than it looks.

Anyway decided to get some numbers on the MM.

Exhaust port, didn’t compensate for curvature. ‍
Calculated from app, 302mm^2
Calculated from 27x12mm, 324mm^2

Muffler openings.
Main opening calculated from app, 315mm^2
Main opening calculated from, 17x21mm, 357mm^2

Calculated total with louvred opening, 358mm^2

Factory screen has openings,
0.55mm * 0.55mm = 0.303mm^2 each.
Mine has 30 * 36 openings.
1080 * 0.303 = 327mm^2
Could raise this to 380mm^2 with some more grinding to expose more screen, or use a different mesh.

So stock exhaust port at piston,,. 302mm^2
Opened up muffler discharge,,,,. 358mm^2
Total combined screen opening,.327mm^2

Muffler discharge 118% of cylinder exhaust port, (150% looks achievable with more work)
Screen opening 108% of cylinder exhaust port, (125%+ achievable with stock mesh)

The main thing I would like to consider would be the discharge coefficient of the mesh, while it's openings equals 108% of the exhaust port, they may cause more restriction than this number shows due to they way the gasses pass through it.

 

[00wyk]

Dolmar 420

 

[Funky sawman]

View attachment 119438 View attachment 119439 View attachment 119440 View attachment 119441 View attachment 119442

Is that a red97 deflector? What size?

 

[Canadian farm boy]

064 mufkin. Ready to bolt on and make some noise

 

[gurwald]

Modified a huztl muffler for my 372, I wanted a spark arrestor so I put one on top and welded the other shut.

 

[mdavlee]

Rescued a neglected 036, runs better than it looks.

Anyway decided to get some numbers on the MM.

Exhaust port, didn’t compensate for curvature. ‍
Calculated from app, 302mm^2
Calculated from 27x12mm, 324mm^2

Muffler openings.
Main opening calculated from app, 315mm^2
Main opening calculated from, 17x21mm, 357mm^2

Calculated total with louvred opening, 358mm^2

Factory screen has openings,
0.55mm * 0.55mm = 0.303mm^2 each.
Mine has 30 * 36 openings.
1080 * 0.303 = 327mm^2
Could raise this to 380mm^2 with some more grinding to expose more screen, or use a different mesh.

So stock exhaust port at piston,,. 302mm^2
Opened up muffler discharge,,,,. 358mm^2
Total combined screen opening,.327mm^2

Muffler discharge 118% of cylinder exhaust port, (150% looks achievable with more work)
Screen opening 108% of cylinder exhaust port, (125%+ achievable with stock mesh)

The main thing I would like to consider would be the discharge coefficient of the mesh, while it's openings equals 108% of the exhaust port, they may cause more restriction than this number shows due to they way the gasses pass through it.

Every edge has some flow disturbance compared to one big hole.

 

[Ketchup]

Rescued a neglected 036, runs better than it looks.

Anyway decided to get some numbers on the MM.

Exhaust port, didn’t compensate for curvature. ‍
Calculated from app, 302mm^2
Calculated from 27x12mm, 324mm^2

Muffler openings.
Main opening calculated from app, 315mm^2
Main opening calculated from, 17x21mm, 357mm^2

Calculated total with louvred opening, 358mm^2

Factory screen has openings,
0.55mm * 0.55mm = 0.303mm^2 each.
Mine has 30 * 36 openings.
1080 * 0.303 = 327mm^2
Could raise this to 380mm^2 with some more grinding to expose more screen, or use a different mesh.

So stock exhaust port at piston,,. 302mm^2
Opened up muffler discharge,,,,. 358mm^2
Total combined screen opening,.327mm^2

Muffler discharge 118% of cylinder exhaust port, (150% looks achievable with more work)
Screen opening 108% of cylinder exhaust port, (125%+ achievable with stock mesh)

The main thing I would like to consider would be the discharge coefficient of the mesh, while it's openings equals 108% of the exhaust port, they may cause more restriction than this number shows due to they way the gasses pass through it.

That’s cool. What app are you using?

 

[Agent Smith]

036 and 044 7/8" tubes

 

[NPKenny]

550xp with Red97 medium deflector.

 

[NPKenny]

550xp continued...

 

[NPKenny]

Here’s one done out of necessity on a previously hacked-up muffler. A good bit of clean-up inside and a scrap piece of rectangular tubing cut to fit for a deflector. The screen is secure and pretty easy to clean / replace.

 

[tickbitintn]

Luke!!
I am your father!!

Sent from my XT1635-01 using Tapatalk

 

[StuntCockWelder]

371 muffin with a little pipe

 

[Moparmyway]

My stumping/milling slut muffler mod







And this is what it looks like when milling or stumping


The stock opening is closed with a piece of aluminum flashing, easily removed if I want to open it back up

 

[00wyk]

Here's some chainsaw idling video porn of that Makita 4300/DOlmar 420 muff mod.

 

[merc_man]

My stumping/milling slut muffler mod

View attachment 217787
View attachment 217776
View attachment 217777



And this is what it looks like when milling or stumpingView attachment 217805


The stock opening is closed with a piece of aluminum flashing, easily removed if I want to open it back upView attachment 217806

Also serves as a hand warmer

Sent from my SM-G950W using Tapatalk

 

[Agent Smith]

Just finished up this dual port muffler for the 026 project im working on. Welded up the factory outlet inside the cover

 

[Benwa]

A little craftsman I did up for a buddy. Some of these have 2 very small louvers for an outlet, on the clutch side, in the rear upper corner of the muffler. They use the partition as the deflector. Nothing crazy, but should flow a little better now.