Exhaust Routing for Duals

[55 Fargo]

Hey all,

Been pondering exhaust routing for split manifolds and/or headers.

Tru duals all the way back?

Cross over pipe yes or no? 

Muffler and pipe size choices?

And  2 pipes into 1 and  followed by larger pipe out muffler.

How pipes effect sound performance and torque...

[casper50]

I used 2 1/4" but a kit full of bends and welded it up myself.   

 

[knuckleharley]

2 hours ago, casper50 said:

I used 2 1/4" but a kit full of bends and welded it up myself.   

 

NOT good enough! We want to hear it! Not much sounds better than an inline 6 with duals.

[casper50]

Still haven't dialed the carbs in yet.  Can't start it in the garage the fumes get thick quick.

 

[55 Fargo]

2 hours ago, knuckleharley said:

NOT good enough! We want to hear it! Not much sounds better than an inline 6 with duals.

I didnt say that its " not good enough". 

I dont always like loud.

My question is not really about sound but routing 2 into 1 and the effects on performance.

 

 

[casper50]

I believe that KH was referring to my 1st video above.

 

[knuckleharley]

18 minutes ago, 55 Fargo Spitfire said:

I didnt say that its " not good enough". 

I dont always like loud.

My question is not really about sound but routing 2 into 1 and the effects on performance.

 

 

I never tried to say,or implied that you did. *I* was saying it's not good enough because I love the sound of split exhausts on a inline engine.

And it's not about "loud",it's about the tone. Or at least it is with me.

[55 Fargo]

4 hours ago, knuckleharley said:

I never tried to say,or implied that you did. *I* was saying it's not good enough because I love the sound of split exhausts on a inline engine.

And it's not about "loud",it's about the tone. Or at least it is with me.

Okay good by me.

Now moving on,  hope to get feedback on exhaust pipe routing, size, cross over pipes or even 2 into 1 pipe. 

 

[knuckleharley]

1 hour ago, 55 Fargo Spitfire said:

Okay good by me.

Now moving on,  hope to get feedback on exhaust pipe routing, size, cross over pipes or even 2 into 1 pipe. 

 

I'd like to hear the pros and cons about a balance tube and the effect one has on the sound of a inline 6.

[55 Fargo]

2 minutes ago, knuckleharley said:

I'd like to hear the pros and cons about a balance tube and the effect one has on the sound of a inline 6.

Sure no problem hopefully someone will clue us in.

Again sound and noise is secondary in this thread.

Performance pro and con and pipe size, routing ir 2 into 1 is what i would like to hear about.

[JOHN EDGE]

I tryed to run true duals out the back of my suburban with Fenton type exhaust manifolds. With the gas tank on the drivers side the routing was limited. Wasted about 20 foot of exhaust pipe trying different routes but nothing looked right or didn't interfere with something under the wagon. Finally run the pair of exhaust pipes parallel to the rear axle and installed a y pipe and run a single larger pipe over the rear end  straight out the back like stock but with a large stainless exhaust tip .

looks nice. I first ran straight pipes without mufflers( have done many that way on v8 flat head ford motors) but it was way to loud. So I settled on two glass pack mufflers that I staggered because I had already done hangers for the exh system. Still has A very noticeable tone

Edited March 9, 2018 by JOHN EDGE
Error

[JOHN EDGE]

Pipe size was 2 inch from manifold to y pipes and then 2 1/2 over rear axle to stainless tip

[Gregarious13]

17 hours ago, knuckleharley said:

I'd like to hear the pros and cons about a balance tube and the effect one has on the sound of a inline 6.

Here, maybe this will help. Not a six, but maybe still useful.

 

Greg

 

 

Edited March 9, 2018 by Gregarious13

[PT81Jan]

On 8.3.2018 at 4:42 PM, 55 Fargo Spitfire said:

Hey all,

Been pondering exhaust routing for split manifolds and/or headers.

Tru duals all the way back?

Cross over pipe yes or no? 

Muffler and pipe size choices?

And  2 pipes into 1 and  followed by larger pipe out muffler.

How pipes effect sound performance and torque...

 

A bit theory regarding the cross pipe question:
Due to the way of operation of engines (combustion strokes) a pulsation of the exhaust gas arises in the exhaust pipe. In case there are 2 (or more) pipes the job of a cross over pipe (= interference pipe) mainly is to amplify and synchronize the pulsation of the different strokes. If properly designed, this achieves a charging effect. Aim is to create a negative pressure just when an exhaust valve opens on a specific combustion chamber. This will soak more exhaust out of this chamber than it normally will do. This in turn causes that more fresh gas can be soaked into the combustion chamber, which leads to an increased combustion an thus an increased engine performance.If the arrangement of  the interference pipe is not properly done this will cause a contrary effect.

Length, diameter and position of the cross over pipe have got influence on that effect. With that it is possible to influence in which speed range the engine develops its best performance.

In case of our 6 cylinder engines you probably (just my assumption) could renounce a cross over pipe, since 3 cylinders each are working together as an unit.

I assume that most folks doesn`t have the equipment (neither do I) to determine which is the best execution. I made some experience with other engines by trial and error. It really had have an (slight) effect on the performance.
If someone wants to get the best achievable performance, it for sure will be worth to deal with that more closely. In case of my flathead 6 I don`t care too much, since my truck is not high performance machine

Jan

 

(P.S.: It definitely has got effect on the sound, which probably most people care about. But this was not the question here)

Edited March 9, 2018 by PT81Jan

[Adam H P15 D30]

I don't think these engines move enough air to make a crossover do anything besides change the tone.

 

Adam

[knuckleharley]

1 hour ago, Adam H P15 D30 said:

I don't think these engines move enough air to make a crossover do anything besides change the tone.

 

Adam

The tone is what it is all about for me. If max HP was all that important,I woudn't leave the inline in the car.

[knuckleharley]

6 hours ago, JOHN EDGE said:

I tryed to run true duals out the back of my suburban with Fenton type exhaust manifolds. With the gas tank on the drivers side the routing was limited. Wasted about 20 foot of exhaust pipe trying different routes but nothing looked right or didn't interfere with something under the wagon. Finally run the pair of exhaust pipes parallel to the rear axle and installed a y pipe and run a single larger pipe over the rear end  straight out the back like stock but with a large stainless exhaust tip .

looks nice. I first ran straight pipes without mufflers( have done many that way on v8 flat head ford motors) but it was way to loud. So I settled on two glass pack mufflers that I staggered because I had already done hangers for the exh system. Still has A very noticeable tone

My plan is to run duals side by side all the way out to the rear bumper,like you did. I might get lazy and dump them out in front of the right rear tire,though. After watching that You Tube test I doubt using a H pipe that short would have any influence of gas velocity at all,and just not worth the trouble for power.  The tone might be worth it,though. Guess I am going to  have to cruise you tube and see if I can find one with a H-Pipe to listen to.

[knuckleharley]

1 hour ago, Gregarious13 said:

Here, maybe this will help. Not a six, but maybe still useful.

 

Greg

 

 

Thanks,Greg.

[55 Fargo]

Here is what mine sounds like with dual walker glasspacks.

Ignore the cobbled together pipes.

I hoping to have all new pipes run this spring dumping out on the right fide both pipes in front of rear fender.

 

Edited March 9, 2018 by 55 Fargo Spitfire

[knuckleharley]

11 minutes ago, 55 Fargo Spitfire said:

Here is what mine sounds like with dual walker glasspacks.

Ignore the cobbled together pipes.

I hoping to have all new pipes run this spring dumping out on the right fide both pipes in front of rear fender.

 

Yeah,I'm liking that! Thanks!

[JOHN EDGE]

I've got the suburban tucked away at the shop but I'll be up there later this week and I'll get some video for the sound and routing.  Has a definite non stock sound