Yanmar Intake Noise Reduction: 412cc 1-Cylinder Generator

Hello everyone,

I own a generator with an air-cooled, single-cylinder Yanmar direct-injection diesel engine.
The generator produces 6000 watts on a single phase (230V/50Hz/3000 RPM).

The entire assembly is housed in a casing mounted on wheels.
Therefore, the engine itself is relatively quiet for a diesel.

The only thing that's noticeably loud is the 'brutal' intake noise.
When you stand next to the generator, about 1 meter away, you can feel the 'thumping' or 'vibration'.
of the intake sound, even on the abdomen.

From the factory, a small air filter box was attached to the intake manifold on the cylinder head of the engine. While it filtered the air, it allowed the intake noise to pass through completely.
The air filter housing was visually only slightly larger than that of a lawnmower engine.

I then removed the air filter housing and fabricated a flange that fits perfectly into the opening of the intake manifold on the cylinder head. I then welded a pipe, approximately 25 cm long and 3 cm in diameter, to this flange, which now protrudes from the side of the engine housing.
'I have now connected several air filter housings from various diesel vehicles (FIAT, VW, Peugeot, whatever was available at the scrapyard) to this pipe in order to reduce the intake noise.'

Unfortunately, without success.

I don't know what to do next. Can you help me?

The generator is in my shed, where I restore my classic car, because there's no electricity available there (and the exhaust pipe leads outside).
As a positive side effect, the unit heats the roof in the winter.
The intake noise is much too loud.

What can I do?

Regards,
Marcus.

Hello,

leg doch die Ansaugleitung einfach nach Draußen, wenns dort niemanden gibt, den das stören könnte. Da"Don't worry, take it easy."

Greetings, buddy.

Hello Buddy,

Okay, I thought so too, but the neighbors have a problem with it.
Especially because I usually work until late at night.
During the day, I'm at work.

Regards,
Marcus.

Hm, something completely different?

If you get along with your neighbors, can't you get electricity from them?

Then, your generator will still be noisy, but you won't need it anymore .

m;

Hello,

Sure, that would be possible, but it would involve a very significant amount of effort.
Putting finances aside for a moment.

I need to lay approximately 50 meters of cable across the roof of the old farmhouse.
Specifically, in the section that extends into my 'shed,' only the old 'two-conductor cloth-covered wires' are installed.
I definitely do not want to connect my device there.

In the front part of the farm, there are only these old pipes as well.
They don't even know what an RCD (Residual Current Device) is there.
NO VDE!!!

So, I would first need to purchase a fuse box for my workshop, then at least 50 meters of 3 x 2.5mm² cable, and...

That's why we need the generator.

There has to be a solution to reduce the intake noise, right?

Regards,
Marcus.

Hello snowman24.

I'm not sure if it will make a difference, but if you use a conical pipe as an intake manifold...
As it enters, the air is gradually accelerated and may become less forceful.
Sounds.

Best regards, Chrigu.

Hello,

So, instead of the round pipe that I installed, just try using a...
Use a conical shape.

I will try that, but I don't think the short length of 25cm will make much of a difference.

There has to be a way to solve this, so that the intake noise is reduced, but the engine still gets enough air.
It's not the 'bright' sound that's disturbing, but the 'deep thumping.'
It's so loud. You could compare it to a very loud sports exhaust (group: A).

Regards,
Marcus.

How about incorporating something like a synthesizer?
Furthermore, I would extend the intake manifold and decouple it using insulation.

Hello Andy280,

Thank you for your help, but if you could also describe it to me now,
what a Symphoser is???!!!???<

And how should I disconnect the intake manifold?
You're writing about insulation...
'I would really appreciate some more details.'

Regards,
Marcus.

This is a type of damping system that allows you to redirect resonances, or unwanted noises.
You can also do this with an external air tank.

Okay, I'd like to build something around the intake manifold that can be dampened.
There shouldn't be a shortage of space, should there?

How about using an old muffler? It would require minimal work and calculations. The only thing you'd need to experiment with is the distance to the engine.

As Christians already wrote, use the largest possible airbox (due to its volume) in the intake system. You already have the flange. You can also add an additional air filter to the front.

Best regards,
Christian.

Hello everyone,

@andy280: I would be very grateful if you could let me know where I can find more detailed information about the principle.

Otherwise, I'll try the thing with the exhaust pipe.

I still have a few of those lying around .

Thank you in advance for your help.

I will get back to you as soon as I have tried it.

Regards,
Marcus.

Here's an example of that.
The butterfly valve can de-throttle the intake path or can also be used to amplify the sound.

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Please check the Mann&hummel website.