what to look for in a diesel muffler? (Kioti LB1914)

[dbotos]

In the market for a new muffler for a 1991 LB1914. OEM replacement is $400 and I'm not paying that. With the heat shield removed, the muffler is about 13 inches long by about 3.375 inches in diameter. Peering into the bottom end of the muffler (where the elbow that bolts to the exhaust manifold was formerly welded to the muffler), I see what looks like remnants of an inner perforated tube (round-hole perforations) and also whitish crystal looking stuff that I'm assuming is fiberglass that was behind the perforated metal.

Which would make it a glasspack muffler like this:

Thrush® Glasspack Muffler

What are people's experiences with this type of muffler on a diesel? Based on how sooty it is inside there, I worry that the fiberglass packing (and possibly the holes in the perforated inner tube) would get clogged up with soot relatively quickly and the muffler would become effectively a soot-lined pipe. What about baffle-type mufflers for a small diesel?

The hole in the square-flange plate of the elbow that bolts up to the manifold is about 1.313 inches and the outlet pipe is a piece of fence top rail that measures 1.315 inches OD. I added the latter to extend it above my canopy and put a flapper on it.

Thanks,
David

P.S. The muffler in the pic is OEM, possibly the original one that came on the tractor.

 

[TractorNoob85]

OEM muffler from 91 lasting up until now is pretty good. Not the worst way to spend $400 if you want something to last a long time.

 

[rScotty]

OEM muffler from 91 lasting up until now is pretty good. Not the worst way to spend $400 if you want something to last a long time.

That's what I was thinking, too. OTOH, last year I just bought a new muffler for our 1958 JD and it was less than $100. Larger, more packing & looks nice, too.... from Steiner Tractor.

 

[Beaver Cove Deere]

Tractor Supply might help.but 400 ain’t much IMO. I like glass packs on street cars and Jake Brakes on big diesel’s but there’s no way I want to listen to either on my tractor.

 

[rScotty]

You can pay more or less. Most tractor mufflers I've seen are about the same. Straight ones have internal pipes with baffle holes punched into them and are wrapped with fibergalss.
Offset mufflers cost more and have two of those baffle pipes inside.
These are NOT your high performance tuned exhausts, just mufflers.

 

[ericm979]

Packing generally does not absorb sound as well as mufflers with tuned chambers but it's more compact. If your muffler is over the engine under the hood then it will have some size constraints but if it's external you can go larger. You might need bracing for a heavier muffler so it does not break the exhaust pipe. If it's a vertical stack an oval muffler would block the view less than a round muffler with the same volume.

 

[dbotos]

Rolled over to Tractor Supply today and looked at what they had. Got a Stanley FO-3 for $50 and a 1.5" flapper for $12. Going to chop the inlet pipe (lower one with the bend) close to the bottom end of the muffler, clean up the elbow from the OEM and weld that there, and probably extend the outlet pipe a bit to make it taller like my old setup. The heat shield makes the OEM muffler look much bigger than it actually is. I looked down inside the Stanley muffler with a flashlight and it's got a center tube with partially-punched holes in it and the still-attached slugs from the holes are bent inward. Apparently this is called a louvered baffle tube if you care to google it.

https://www.tractorsupply.com/tsc/product/stanley-muffler-company-inlet-aluminized-muffler-fo-3

 

[dbotos]

Got the elbow cleaned up. Needle scaler worked great for getting crap out of the inside (soot + flaky scale). Used an angle grinder around the outside and a benchtop belt sander to square up the end.

I cut the inlet pipe of the muffler to 2 inches long. Flared that on the anvil by holding it on the horn and smacking the outlet pipe with an oak pallet piece and turning it in increments to make sure it was relatively even all around.

 

[Williy]

Good Job!

willy

 

[dbotos]

Thanks!

 

[CJFONNER]

Looking forward to hearing if you’re happy with the volume/sound of the new muffler. Please share your feedback once you’ve got some seat time in.

 

[dbotos]

I'm assuming it will be an improvement since the old muffler was basically just a fat section of pipe with all the guts having rotted out. I got everything welded up this evening. They're no beauty-pagent welds, but they're solid and I did look down the outlet with my flashlight and there was no weld intrusion into the ID, which was nice. Hoping to get some seat time later this week and I'll report back.

One of these days, I'm going to fix my sagging canopy. It's a dumpster lid from one of those square-footprint dumpsters with the two flaps. It was in the big dumpster at work one day and I knew just what to do with it. I think if I made a perimeter frame for it out of scrap angle iron, I could bring the support braces to the midpoint of the sides instead of the front and that would work better. The sagging canopy makes the exhaust look taller than it is.

 

[dbotos]

Sound level of the new exhaust seems roughly the same as the old one. The normal mechanical "dieseling" noise from the engine (which hasn't changed) sounds louder than the exhaust. I never really thought about that until trying to listen to the new exhaust. The LB1914's engine bay is just metal panels with no sound deadening/absorbing material on the inside (and plenty of openings for sound to escape).

I'd call the replacement a success - I spent a little bit of time and effort to save some money compared to buying a new OEM muffler and now the tractor is functional again. Going to pull the new setup off at some point and paint it black with high-temp paint.