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Running a Generator With No Muffler


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  #1  
Old 01-06-2018, 09:08:51 PM
KPack KPack is offline
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Default Running a Generator With No Muffler

When testing a generator how long can you run it without a muffler or is it bad to do it ?
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Old 01-06-2018, 09:15:58 PM
len k len k is online now
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Default Re: Running a generator with no muffler

Till your ears bleed, or neighbors come with pitch forks. Over summer ran my JB without a muffler didn't think it was that loud , till I saw my neighbor and his wife starting hard at me from their deck..... that they had to get a variance to build closer to my property line than zoning allows.

I suspect it's not a problem, except for your ears. I suspect muffler only makes a small bit of back pressure that's pretty small compared to the high pressure in cylinder. So it shouldn't have any significant effect on exhaust flow rate , for heating exhaust valve. Think muffler only adds maybe 2 ?? psi backpressure, think cylinder pressure is 150-450 psi while burning.
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Old 01-06-2018, 09:40:54 PM
consolenut consolenut is offline
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Default Re: Running a generator with no muffler

Well from what I know of car engines. Its not good run an engine without a muffler long term. Unless its designed too. As its possible to burn a valve. Just my opinion.
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Old 01-06-2018, 09:50:17 PM
Birken Vogt Birken Vogt is offline
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Default Re: Running a generator with no muffler

https://www.youtube.com/watch?v=jjPeP_Nn2B4&t=157s
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Old 01-06-2018, 10:09:18 PM
AngrySailor AngrySailor is offline
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Default Re: Running a generator with no muffler

It's not so much the lack of muffler that causes valve issues, it's the length of the exhaust opening away from the valve... if you remove a muffler and run with just the short port, air reversion can cool a hot exhaust valve causing thermal shock, if you add a short length of pipe to prevent this reversion you should be fine.
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Old 01-06-2018, 10:55:08 PM
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Default Re: Running a generator with no muffler

What Len said.
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Old 01-06-2018, 10:59:43 PM
Gunny Gunny is offline
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Default Re: Running a generator with no muffler

No issues. I've run a lot of them on load banks for up to 24 hours with no mufflers (silencer) at 100% load. A Cat 3516 had an orange flame about 2' standing out of the flower pot at night.

The engine may run a little more efficiently with a littl eback pressure on the exhaust, depends on the cam profile. Have run motorcycle engines with no exhaust at all, right out of the head, never burned or warped a valve. Made some ears hurt.
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Old 01-07-2018, 07:58:39 AM
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lokay5 lokay5 is offline
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Default Re: Running a generator with no muffler

Quote:
Originally Posted by consolenut View Post
Well from what I know of car engines. Its not good run an engine without a muffler long term. Unless its designed too. As its possible to burn a valve. Just my opinion.
Just an old urban myth.
An engine would be more likely to "burn" a valve with a muffler.

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Originally Posted by AngrySailor View Post
It's not so much the lack of muffler that causes valve issues, it's the length of the exhaust opening away from the valve... if you remove a muffler and run with just the short port, air reversion can cool a hot exhaust valve causing thermal shock, if you add a short length of pipe to prevent this reversion you should be fine.
"...air reversion can cool a hot exhaust valve causing thermal shock"

Urban myth
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Old 01-07-2018, 08:25:32 AM
Handyhiker1 Handyhiker1 is offline
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Default Re: Running a Generator With No Muffler

On a constant speed engine it is not going to hurt anything. When the RPM drops suddenly that is when the possibility to suck cold air back into the exhaust and damage the hot exhaust valve.
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Old 01-07-2018, 09:47:28 AM
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BRae BRae is offline
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Default Re: Running a Generator With No Muffler

The engines efficiency may change some however, I doubt it will damage anything but your ears.
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