What is it that makes a Cummins sound like a Cummins?

[DZink24]

This question may not have an answer, and it may be a stupid question. I may be crazy, but am I the only one that just "knows" that a big rig, dump truck or 18 wheeler has the big C under the hood, just by the sound? Obviously, our trucks sound the same as many Fed Ex and UPS trucks, because well, they are running the 5. 9 as well. But for example, what is it that makes my straight piped truck sound almost identical to, lets say a Pete with a straight piped M-11 under the hood? It is just uncanny how it seems that all Cummins sound very similar to each other, and can definitely stand out against Cats, Detroits, Internationals, Isuzu, ect.



Is it similiar parts used across the Cummins line, like injectors, turbos, manifolds, and injection pumps?



My response to friends that say "God, your truck sounds like a Mack dump truck!" is , "um no, actually, it sounds like a KW pulling a 15 ton dozer up a grade. Jealous?"



*OR* am I nuts and Cummins are in a pretty even mix of big trucks, and not mostly in Petes and KW? Don't be shy

 

[MForbus]

I have noticed the same thing! My friends truck is straight piped and has a five inch exhaust from the turbo back! You can here it coming down the street. But when a delivery truck goes by it sounds just like his! And I have no idea why! But his truck sounds and looks way better!

 

[PToombs]

I pulled in to my buddys shop the day after I put the 4" exhaust on. The secretary came out and said "Oh, it's you! I thought a dump truck pulled in!" :-laf

 

[Gary - K7GLD]

Much of the mechanical sound from our trucks is caused by the injection pump - some guys who have seen/heard the pumps running on test stands have commented on how similar the pump sound itself is to what they had figured was the engine...

 

[JFlagg]

The folks at my work say mine sounds like a duece and a half I know the newer 5 tons have Cummins in them, but not sure about the old duece's... I know the inline diesels all sounds more like diesels than the V diesels (Powerstrokes, duramaxes, etc). But other than block shape, I can't help you there...

 

[John - K5AWO]

It's that straight six inline engine. V8's, V10's, nothing can match the sound of a healthy straight six.

 

[2broke2smoke]

It's that straight six inline engine. V8's, V10's, nothing can match the sound of a healthy straight six.

what he said

 

[JFlagg]

I agree, my little 30something HP Kubota inline 3 sounds more like a diesel than a Ford or Chevy:-laf

 

[AKaiser]

The folks at my work say mine sounds like a duece and a half I know the newer 5 tons have Cummins in them, but not sure about the old duece's... I know the inline diesels all sounds more like diesels than the V diesels (Powerstrokes, duramaxes, etc). But other than block shape, I can't help you there...

Most of the old 2 1/2 Tons had Hercules multifuel engines in them. The M8xx series 5 tons had the C series engines retrofitted, and the M9XX series came with them. The new LMTVs (2. 5T 4x4s) and the MTVs (5T 6x6s) have Cat 3116 ATAAC, 6. 6L engines rated at 290 HP. I figured at least a C7 for the 5 ton, but was wrong. We picked up a large handfull of these trucks on Monday. They are nice trucks, sound sweet, but there are concerns about the 3116 engine.



http://www.fas.org/man/dod-101/sys/land/m1078.htm

 

[Vaughn MacKenzie]

Much of the mechanical sound from our trucks is caused by the injection pump - some guys who have seen/heard the pumps running on test stands have commented on how similar the pump sound itself is to what they had figured was the engine...

When my P-pump was on the stand it was so dang loud when the rack was set for WOT I had to plug my ears.

 

[JasonCzerak]

So the knock you hear is the fuel being let go and not detonating?

 

[DZink24]

The local metro transport company runs handicap accessible buses, they are Ford F450s. Do these have Cummins in them, because as we all know, Ford owns Cummings, or are they Ford motors, with the same fuel pumps as our trucks? At idle, they sound quite a bit like a HPCR.



I can sit in my living room with the windows open, not even looking, I can tell when a Cummins pulls up to the light. There is no mistaking that sound. Especially the 24 V!!

 

[Missouri Mule]

It is probably the design of all the Cummins engines being similar and may be they are using the same injector pump as the 5. 9s.

 

[nickleinonen]

most all inline 6 diesels sound similar when they are of similar displacement i find. .
a isx cummins sounds similar to a s60 detroit. both are overhead cam engines, both have cam actuated injectiors [hpi/tp on cummins, eui on detroit]
n14 cummins sounds similar to a mack e7 [eup on mack, eui on cummins]

 

[rbattelle]

Let's think about what any particular engine sound is a function of. Probably things like,

-block material and casting method
-cylinder design and materials
-valvetrain design and materials
-number of cylinders and arrangement
-combustion chamber shape
-injector pump design

I'm sure there are lots of other things, but my point here is that subtle differences in each of these items will change the audio signature in subtle, but important, ways. I'm sure that each individual engine in the world has an absolutely unique sound signature, just like a fingerprint.

It's logical, therefore, that engines designed with similar parameters are going to sound similar. I'm sure Cummins has certain design standards to which each of their engines are designed, so that's going to cause their engines to carry certain common acoustical features across the entire product line.

I think it makes sense. Imagine, for a moment, 2 identical 5. 9L engines. Identical shape, mass, injection pump, head, turbo, everything. But one of the blocks was cast slightly differently than the other - with slightly higher ductility, for example. Chances are, a good ear could distinguish these two engines.

Ryan

 

[EMD-Run8]

Inline 6 Bubba! But... ..... A V-12 sounds REAL good too!

 

[tgordon]

Gotta be the rattle especially straight piped going under a overpass under load, thought for sure the cop would throw on his lights:-laf



Friend helped me move, over 1200 miles round trip, my stock 12v still makes him want to junk his duramax. He would comment as we pulled out of th etoll boths how nice it sounded, when we ran next to each other on th eexpressway how he couldn't hear his own truck, and how when we filled up mine took less fuel everytime, oh well guess I have somebody in line to sell it to should I ever deicide to part ways.



Troy

 

[NIsaacs]

Cummins inline 6 engines do seem to have a sound of their own, even in comparison with other inline 6 manufactures. I think it is in the cam timing, also with the fuel injection timing.



Nuthin sounds better than the old 275 w/factory roots blower and back draft manifold. At night, under a good pull, the glow coming out of the stack (s) on the rearview mirrors would send a happy chill up yer spine





"NICK"

 

[Greenleaf]

There is a new employee here at the bus garage. She was here really early her first day and I arrived soon after. She commented that my pick-up sounded like a big rig.