Exhaust Volume

[sparks57]

Does horsepower regulate exhaust loudness in a straightpiped cummins? Why do the 24v trucks sound louder, and slightly harsher than the 12v trucks? Is it the HP or does it have something to do with the valve system?



Thanks.

 

[sparks57]

Nobody knows?????

 

[Rams-n-Hogs]

The 24V has too many valves, so it makes more noise.



Jim

 

[EMD Diesel Power]

The more HP you have in an engine, the louder it will be. Same is true for size of the engine as well.



Pump noise might have something to do with it too... . sometimes its hard to differentiate between the pump and true engine/exhaust noise.



I do know that the ECMs on the 24Vs adjusts the timing when cold. One of the reasons that it sounds like crap IMHO and is noisy when first started compared to a 12V.



didnt somebody mention airflow/HP/noise comparison in this thread?? Basically HP is fuel burned..... more fuel needs more air... . and you'll have a louder (or deeper) exhaust. compare a B5. 9 to a N14/ISX to a QSK19(?) to an EMD 567/645/710/265H. You get the picture.







Oo. Oo. Oo. hope that helps a little. I can research this further if you want... . will take some time though. Need to go thru my diesel books again.

 

[sparks57]

That was just the answer I was looking for.



Thanks a lot!

 

[Ncostello]

I was in the pump room at Scheid once to watch them install a performance plate in a P7100. They test ran it and flowed diesel into the measuring beakers for each cylinder. As the machine spun up the pump... I was amazed at the sound. I was told to wear ear plugs too. It sounded exactly like a 12V Cummins was running in the room at full throttle. Which kinda made me realize much of the sound you hear is the injection pump and not really the combustion/exhaust. I've never heard a VP44 run on a test stand (but then again who has?). But I bet thats the difference in sound. Compressing fuel up to very high pressures sure aint quiet... and the 24's are higher pressure.

 

[bmoeller]

Those pumps are loud. Was suprised the first time I heard one on a stand also.



John Deere is using the HPCR system also. Both the combine and the 8420 tractor that I run have it. They are a little louder than the previous engines w/in-line pumps they replaced.