Lister Engines > Lister Based Generators

Exhaust System

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Quoth T19:

"How do you like the muffler???  It looks like the Princess Auto tractor onces I have seen, does it work well?  I've seen straight pipe and auto.  I would like to silence mine like that one at utterpower by Jeff, who lives in a suburb.... just thinking about the wife"

My verbose reply follows:

I’d been thinking about how to silence my 6/1’s staccato “pop-pop-pop” for some time.  The stock pepper-can muffler is not up to the task of achieving meaningful sound reduction, although it did contain something that I could use:  a 1.5” British Standard Pipe Taper (BSPT) pipe nipple that I needed to adapt the exhaust system to the threaded exhaust flange.  (McMaster-Carr carries them too.  Search under “BSPT” and “nipple”).

Several DIY’ers have used auto  mufflers for their engines, but they suffer from a few disadvantages.  First, they’re intended to be fully suspended  from beneath the car’s body on rubber hangers which means simply welding one on to the exhaust nipple wouldn’t work, so they are simply not strong enough to be end-mounted.  They are also rather ugly and will rust if exposed to the weather.  Finally, they are also about twice as expensive as an equivalent sized tractor muffler.  Tractor Parts, Inc. carries inexpensive, rugged mufflers that are designed to be supported from one end.  They last for years totally exposed to the weather.   I found one for under $20 that was adaptable to the 1.5” exhaust nipple.

I freed the nipple from the pepper-can by making several plunge cuts through the thin metal pepper-can with a cutting disk attached to a 4.5” angle grinder.  After liberating the nipple I welded one end to a 1.5” diameter unthreaded steel weld-ell (McMaster-Carr part no. 43425K151).  To the other end I welded a 1.75” exhaust sleeve, which is available from any auto parts shop.  The inlet tube on the muffler slips into the sleeve and is held in place with a muffler clamp. 

I also picked up a weather cap to keep rain and damp air out of the muffler during periods of non-use.

After tightening all the connections, I cranked the engine over and was surprised at how quiet it was.  The former “pop-pop-pop” sound is now a subdued “pooh-pooh-pooh.”  You can now clearly hear the tappets and valves clicking between exhaust pulses. 

Ultimately when I permanently locate the engine, the muffler will be fastened more securely, but for now, it does the job.



Here's a closeup of the muffler and plumbing arrangement.  Muffler is much more rigid and heavily made than one for a car.


You might want to rethink the mount from the head to the muffler.  The boss around the exhaust port can crack from the weight of the muffler and engine vibration.  That's a LOT of leverage on two bolts three inches apart.
     Its' better to suspend the muffler from a seperate structure and connect it to the engine with a piece of flex pipe.  You also need a "T" in the line as a moisture trap and drain just short of the head.   Everytime you shut down condensation forms inside the muffler and trickles acid water into the head with what you have now.  In that direction lies rusty rings and pitted cylinder walls and ingrown toenails .....    ;D

Get a 'street T' with a swoop in one side to reduce backforce...or go to larger pipe between the engine and muffler and use a standard 'T'.  The backforce will be the same.

NICE rig!!   I want to see that engine after a hundred hour run and no wipe down.... I call my green one the 'watermellon'.  Yours will be an inkblot test!  ;D ;D


Yes, I don't recommend mounting a muffler this way for very long.  However the camera lens distorts the size and position of the muffler somewhat, so the center of mass is not cantilevered as far as it looks.  That's why I indicated this is temporary, i.e. for demonstration and testing, until I get the engine moved.

You know how it is when people come by and want to hear it start up.  I've met more folks out walking their dogs, the mailman, UPS, FedEx and pizza delivery guys, even a couple of very earnest young men in starched white shirts from Utah who wanted to talk with me about the state of my soul.  All took their turn cranking it over, and all left with big grins ontheir faces and thoroughly enjoyed the sound of the engine.

I'm preparing to mount the engine on a slab next to a concrete retaining wall.  When I do, the muffler (and radiator/expansion tank) will mount to the wall and connect via flex pipe with a proper drip trap.  However this engine is pretty smooth, so there is little whipping action. 

Regarding the gaskets, yes there are a few leaks that I have to address.  When I initially stripped the engine I cleaned the gaskets and smeared them with RTV, then squeegied them smooth to allow me to remove them during future teardowns.  Filed the mating surfaces, too.  After the gaskets dried I put it back together and have only one or two leaks that I can find.  Once it gets a load on it and heats up I'm sure that will change, though. 


Hello Everyone!

My name is Mike Montieth. I just found this forum and am finding it very interesting. I imported the first of the Lister type engines to America years ago. I've been is school the past several years so I have not had a big internet presence. I'm currently teaching Intro to Engineering and Manufacturing Materials and Engineering at a local college. It looks like the Lister engines have really taken off! Since I have many years of experience with the Lister type engines I'm seeing a lot of misinformation and hype about them that I'd like to help clear up. First, the Lister type engines do hold up very well and can easily be made to run almost silently. I'll post some photos of my 6/1 installation once i get back to my warehouse. The 6/1 is pulling a 7.2 kw 3 phase generator and furnishing the power for the building. I use 2 Nissan Sentra mufflers, one to silence the exhaust and one on the intake since it was now louder than the exhaust. I built a 2 bolt flange which I welded to a 1 1/2" pipe stub. I machined the stub to 1 3/4" to fit the sentra muffler. The original threaded exhaust manifold was moved to the intake side and a short nipple of 1 1/2" pipe was threaded into the manifold after also being turned to 1 3/4". I sell the GM-90 series engines which are far more advanced technologically than the original Lister engines. These engines have a fully counterweighted crankshaft and run smoother than a standard 6/1 so vibration is not a problem. These engines also have real oil pressure to the rod bearing, not splash like all the other Lister type engines. The result is that the loudest thing you can hear is the valves clicking. The exhaust is amazingly quiet. I have mine simply run through the wall and 20 feet away it can hardly be heard. There is no exhaust noise inside the building. I've got a lot of other hints and kinks that I can post about the Lister type engines that will work with any of the Lister type engines, regardless of the manufacturer. More on that later!


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