Why does one truck 'whistle' more? Both -1C w/ C tubos

[Hammer]

Ok, I have two 1971 AM General M35A2s that both have -1C motors, and both have C turbos.
One was built in 77, the other in 78.
Both trucks whistle, but one will whistle a LOT more then the other.

I have a 69 Kaiser that has the -1D motor with the D turbo. So I know the difference in turbos and the sounds.

I turned up the pump a little in the 'dog whistler' (cause I can barely hear it). Not too much change. It will whistle sooner because I am putting more fuel in, but not nearly the same as the loud truck.

Any ideas why one whistles THAT much louder then the other?

 

[EZFEED]

RE: Why does one truck

Bearing wear maybe?????

 

[maxim]

RE: Why does one truck

I have not encountered a 'whistler' that is more pronounced than mine of all the trucks I have heard. 1971 AM General Contenental. Maybe it is happy.....I drove a D turbo for 10 hours and it left me with an empty feeling somehow.

 

[dm22630]

RE: Why does one truck

I have a few whistlers. Some are much louder than others. The only thing I can guess would be mileage on the engine....

 

[Hammer]

RE: Why does one truck

No idea on mileage as it looks like the louder truck has newer speedo and tach.

 

[jfoose]

RE: Why does one truck

I may be out of my territory here, but does the truck have a silencer ring on the turbo? It has been referred to as a anti-surge ring by some, but it does not prevent surge, it just limits the amount of audible turbo whistle. I know my dodge came with one... it was easy to remove with a pick and some pliers.

 

[Hammer]

RE: Why does one truck

I don't think these even have those.
And yeah, I pulled the silencer off my dodge as well.

 

[EZFEED]

RE: Why does one truck

OK, how tightly is you exhaust mounted? Any loosness will transmit to extra vibration.

 

[StreetbikeDepot]

RE: Why does one truck

How do I identify the different types of turbos? Are they marked or have a number stamped in the housing?

 

[Hammer]

RE: Why does one truck

The exhaust housing on the D turbo is wide. Whereas the C turbo narrows down noticeably.
Search and you will see plenty of pictures on this.

Both exhausts seem tightly mounted.

 

[dm22630]

Here are pics of a d-turbo & c-turbo

C's are the "whistler" turbos

 

[randyscycle]

Re: RE: Why does one truck

How do I identify the different types of turbos? Are they marked or have a number stamped in the housing?

Go out, fire up your truck, and try to have a conversation within 25 yards of it. If you can't understand what the other person is saying, you definitely own a Whistler.

 

[Hammer]

RE: Re: RE: Why does one truck

Hmm, I went and looked again, the quieter one is actually a 1988 motor, NOT an 1978.
And it is definitely a lot quieter as far as the whistle goes.

Tempted to pull both turbo's and examine them. After that, polish and clean them up (inside for performance, not outside for looks).
And install the EGT probe.

Ack, I need to sell one of these, and I want to make sure I keep the one I WANT. Tough call as they are almost the exact same.

 

[StreetbikeDepot]

RE: Re: RE: Why does one truck

so....I have a deuce with a c motor and it has a different turbo than either of those.....kind of a cross between the two. Any ideas? Does a have a steel tag on the inlet side of the turbo. I'll try to read it.

 

[StreetbikeDepot]

RE: Re: RE: Why does one truck

Says its a 3LD-305.....good,bad, any info?

 

[otisroy]

RE: Re: RE: Why does one truck

Is that orange innerduct?

 

[bulldog_mack13]

RE: Re: RE: Why does one truck

slobber tube

 

[kcimb]

RE: Re: RE: Why does one truck

Perhaps one truck is from West Virginia.

 

[dm22630]

Re: RE: Re: RE: Why does one truck

so....I have a deuce with a c motor and it has a different turbo than either of those.....kind of a cross between the two. Any ideas? Does a have a steel tag on the inlet side of the turbo. I'll try to read it.

That turbo is off of a LDS427 motor.

Read this thread ---> http://steelsoldiers.com/index.php?name=PNphpBB2&file=viewtopic&t=24543

Here is a picture....

 

[Barrman]

RE: Re: RE: Re: RE: Why does one truck

Hammer,
I am looking for the same answer. We drove the 4 trucks back from OKC this weekend. All of them have the C turbo and all whistle varying degrees of loud. My truck has the loudest whistle. so loud that standing 200 yards away up wind, you can hear the whistle but not the truck. At night you can't locate the truck by sound alone because the whistle can be heard so far away and seems omni directional bouncing off buildings and such. The other trucks just whistle but not near as much.

3 of them are 1970 trucks and 1 is a 1968. They came from the OK NG in the same sale and have rebuild tags with the same date on the engines.