Go Figure

[Greenleaf]

Guys, Ponder this... ... ... ... ...



While we are fresh on the subject of exhaust systems, I call you'r attention to the 5. 9 in my buses. They, for the most part have the HX35 w/14 or 12cm waste gated. All of them be it 12 or 24 valve. The down pipe is 3" leading into the muffler, which is about the size of a 55 Gal drum. At which point the exhaust is a 4" to the leading edge of the rear duals.



The engine comparable to this is the DT360, if you can call it comparable

Anyhow, these engines have the 4" exhaust throughout.



Greenleaf

 

[JLEONARD]

down pipe is 3" leading into the muffler, which is about the size of a 55 Gal drum

It all comes down to backpressure... . the system needs to satisfy minimum requirements set forth bu Cummins.

I went thru this when I re-powered by boat. Spec is 3 in Hg max.

For the 270 hp marine, minimum exhaust diameter is 5 inch... but remember I have a 1 1/2 inch water hose feeding in for cooling.

Since I did the install myself I had to get it inspected by a Cummins technician.

He hooked up a "womanometer" **to the exhaust and we took readings thru the entire rpm range. Most backpressure was 1. 5 at about 900 rpm. It went to 0 soon after that. I think the turbocharger helps out a bit.

Now I'm exhausted after writing all this!!!!

Jay





** Really a manometer, but I wanted to see who was sleeping!!

 

[Greenleaf]

Yah, I cough that... ... ... . Twas listening



That brings up an interesting subject, not the back pressure. Rather the "womanometer" It just so happens... . I have one. The problem is... . I can't seem to shut it off... .....



Name withheld to protect the victim

 

[JLEONARD]

womanometer

Yes been known to relieve, er... , I mean measure the backpressure from time to time

 

[dpuckett]

Jay,

Wont relieving the backpressure make the womanometer disappear temporarily? Always did mine; that or she let off some pressure of her own.



Daniel