dual exhaust without seperation on same manifold???

[Powerhouse]

Anyone know if this would be a bad thing? I don't see why...it just like running a larger exhaust pipe...

So if a stock exhaust had a dump out back(as stock) and a second dump in the middle...where the riser used to be. That's what I have now since my bad welding didn't hold the seperation plate I put in there. The thing cam loose and rattles around insanely! SOUNDS horrible!

Listen:

http://s8.photobucket.com/albums/a9/m_maringola/?action=view&current=MVI_0050.mp4

See:

Edited February 17, 2012 by Powerhouse

[james49ply]

take out the loose plate and toss it, let the exhaust flow where it may, quick fix, but better if you have a professional weld it for you?

[Powerhouse]

yeah...that was literally my 2nd time welding...and without supervision...it was fun though. I love having access to tools like that at work. I've seen my father in law weld many times and have helped him hold things in place. So I kinda new what to do. I just made sure the settings and material were all correct on the machine and started melting some metal together.

It lasted for about 2 months...noise started right in the middle of doing a valve lash adjustment and scared the crap out of me...I thought something busted when I did the adjustment. hahaha Pretty good trick on me!

Took it out today...It sounds a bit throatier now...I kinda like it.

[greg g]

like any other fluid exhaust flow will take the route of least resistance. So it is pretty unlikely that exhaust from number one cylinder will find it way to mingling with flow from number 5.

The block off may have some effect on how the system sounds but not much on how efficiently it works.

[Robert Horne]

Someone posted this dual exhaust photo on here, having the second pipe near the center of the manifold.

[Olddaddy]

The whole idea is to increase the available exit area of the exhaust, to increase the flow rate by doubling the exhaust outlets. I put mine just forward of the center of the manifold. This is an arbitrary position, but I chose it because it evenly divides the six exhaust outlets with three being closer to one outlet and three closer to the other. In a true dual exhaust a balance tube is needed in the system somewhere, but this method makes that unnecessary. I run the two dumps into a low restriction muffler, two in and one out.

[Andydodge]

This is what I intend to run eventually.......this was made from 2 exhaust manifolds with the heat risor removed from both. As I live in a fairly temperate area, I hope I won't need the exhaust to heat the intake, however if it turns out I do need some heat i will make up a water heated plate to bolt to the intake bottom.........andyd

[randroid]

Gents,

One item conspicuous in its absence from the many posts made on the topic of dual exhausts is the importance of laminar flow verses turbulent flow. It has been mentioned, of course, but more in passing than in substance. I am curious as to whether or not anyone has ever done an accurate measurement of the difference in efficiency before\after a decent interior polishing in our cast manifolds.

I am a proponent of dual exhaust systems and would probably opt for a well polished exhaust before dual carbs, although that could be considered a moot point because the two were made for each other like a helpless woman and railroad tracks.

-Randy

[msawdey44]

Tom Langdon (Stovebolt) has a heat plate available for Mopars. I'm not sure it is listed in his catalog, but he does sell one--not that it would be very difficult to make one....

[pflaming]

Ranroid: How would one test and compare the difference? I might be interested if someone would give me good instructions. I have an extra manifold set, so I could smooth it out, test the one on the engine, then replace and test again. A bit of work but then this IS a hobby.

[Rusty O'Toole]

Not sure if it makes a diff to performance but have heard it will "sound better" if you weld in a divider plate with a hole in it.

[Powerhouse]

Howdy folks,

I drove up to Long Beach and back over the weekend..about 100 miles each way. Seemed to drive strong and smooth(aside from the OD tranny noise and sloppy steering.) The "open flow" dual exhaust did however make it quite a bit louder/"throatier" than with the plate in there at high speeds. We were stuck in bumper to bumper traffic from Camp Pendleton to San Juan Capistrano, over 1/3 of the drive. Didn't get hot a bit but what a pain.

[Powerhouse]

Someone posted this dual exhaust photo on here, having the second pipe near the center of the manifold.

That is exactly what I did after seeing this photo a little while back. Since I am no good at welding...this was pretty much a "bolt-on". I had to make a plate with 4 holes for the cover, plug up the two holes for the heat riser rod, cut a hole in the bottom for outlet...and originally welded a plate to separate the front and rear 3 cylinders....which didn't last obviously or this thread wouldn't be here. hahaha

[Don Coatney]

In a true dual exhaust a balance tube is needed in the system somewhere,

I would think that in a true dual exhaust there is no inter connection or balance tube connecting the two. In my exhaust manifold the original heat riser flapper is welded so it does a true seporation between the front 3 cylinders and the rear three.

My exhaust sounds great and my engine runs great. Why is a balance tube required?

[Young Ed]

I can't explain why its helps but typically high performance V8s run an X or Y pipe down the exhaust system. Perhaps it matters more when you have a v8 making 500HP.

[Frank Elder]

I can't explain why its helps but typically high performance V8s run an X or Y pipe down the exhaust system. Perhaps it matters more when you have a v8 making 500HP.

X or H pipes swap exhaust pulses from one pipe to another for a smoother exhaust with less drone........may also scavange a little more horsepower, not sure about that though.

[martybose]

X or H pipes swap exhaust pulses from one pipe to another for a smoother exhaust with less drone........may also scavange a little more horsepower, not sure about that though.

You have to remember that a V-8 has uneven firing pulses within a bank, so the crossover helps when there are 2 pulses only 90 degrees apart.

Our inline sixes don't have that problem; the front three are 240 degrees apart evenly, as are the back three cylinders.

Marty

[Frank Elder]

Thanks Marty, but I was refering to Ed's V8 query:)