Old dog and new dual exhaust trick.......

[Olddaddy]

I made up a few of these dual exhaust adapters after seeing a picture of one here on the forum. Old dogs can learn new tricks! I like this method even better than my usual traditional brazing method. It doesn't require a broken manifold for the second dump. It only requires that you use a 1 1/2" hole saw to open up the bottom of the manifold. Then bolt on the adapter using the four bolts that hold the two manifolds together. I made the length match the original dump and made the flange the same size so your exhausts will be similar to one another. I like that it moves the second dump back away from the fuel pump too! My hat's off to whoever made the one in the picture, I owe you a favor at least! I'm going to add them to the Rustyhope lineup tomorrow, $65 shipped to lower 48 US address.

[my1946trk]

thats cool but where did you get those pulleys thats real cool

[Olddaddy]

The engine isn't mine, it's one I saw here on the forum. I'd like to know about the pulleys myself!

[55 Fargo]

Very slick, great idea........

[Andydodge]

Thats the engine from Bill Shield's 39 Dodge Coupe that went in the 2010 Peking to Paris Motor Rally, 8923 miles in 37 days......theres an article about the rally & car in Street Rodder Premium Vol 2 # 1, Summer 2011.......I recognised the distinctive upper shock mounts.......doesn't have a pic of the exhaust side to see that header setup but its the engine all right.........your comment about the fuel pump clearance is right tho'...........see the attached pic of my propsed setup....and I've got a steering box to go between the oil & fuel pumps also........lol.......thats a neat setup they/you have done.........andyd

[pflaming]

I would guess there are several reasons for duals: sound, looks, and faster exhaust escape. So can the latter be achieved by putting those two outlets into one "larger" exhaust pipe that connects to the muffler? I'm not crazy about maintaining two exhaust pipes / mufflers, but the increased air flow would interest me.

[Andydodge]

Re the pulleys, from the pics in the magazine I'd say all the pulleys are billet, made for the job alloy pulleys.andyd

[Olddaddy]

I have never used duals on any of my cars or trucks. The double pipes, hangers, mufflers, and the balance tube never appealed to me. I run the two exhaust pipes into one high flow muffler with one large diameter tailpipe. Flows nice, sounds good, and fits the available space quite well. Just my opinion, not knocking anybody's dual setup. I am currently impressed with the Flowmaster Hushpower mufflers, but there are lots of options out there.

[Don Coatney]

Is there a true split with this setup? If so how did you block off the manifold internals?

[Olddaddy]

Don, if you want truly separate duals you would have to braze or weld a piece into the manifold behind where the plate bolts on. Nothing against "true" duals, but I've never installed them.

[Frank Elder]

So you don't really offer "true" duals......just a stock manifold with 2 dumps. I see no advantage to that other than it will sound different. To be true duals you would put a plate in the middle and one dump per 3 exhausts.......and keep the pipes separate all the way out the back to get any benefits out of it.

[Robert Horne]

The advantage of two pipes, "true" or not, would be that you would have less backpressure near the engine.

If you run "true" duals all the way, many people add a "H" pipe to balance backpressure, one pipe with another.

[Olddaddy]

On the manifolds I braze up I can separate the two halves and have done when asked. I've also cut manifolds in two and made two separate manifolds from one stock manifold. The idea with this adapter was to double the outlets without all the shipping and brazing and costs. A quicker and simpler route to two outlets. I wasn't starting an argument, just stating my preference for a simplified two into one exhaust.

[Frank Elder]

There is a difference between an arguement and a discussion....I ain't mad at ya:)

Also if the whole point of duals on our flat 6 is to have that radial engine sound the an H pipe will ruin that sound by making the exhaust pulse too mellow.

[Andydodge]

One day this is what I'll have on my 41 Coupe.........one day.....lol........AND is do like what oldaddy has done, neat & simple.............Andy Douglas

[Olddaddy]

Yeah, I guess it would take some real effort to pick a fight on this forum! I'm always glad to hear the other point of view, I just usually can't afford it...financially I mean. I'm old enough to remember that I started driving old cars because they were cheap. Those days are gone as are most of what I remember anymore.

[Frank Elder]

One of the guys on here hadda different twist also....weld a plate to separate the manifold but the plate already had a small hole drilled in it so the pulses could exchange before they exited the dual dumps. All for a different sound:).

[greg g]

seems it would be easy to weld a plate perpendicular to the top block off plate that would serve to seperate the two ends effectively enough for the purpose. However there may be a question with the thickness of the top plate as any intake that is chambered for an exhaust heat exchange has scant little clearence between the manifolds. Might need to have some machining done to fit a substantial enough plate.

I have blocked mine with a piece of stainless sheet that is about the same thickness as the gasket that usually separates the maifolds, and I needed to countersink the screws I fastened the plate on with.

[Don Coatney]

Don, if you want truly separate duals you would have to braze or weld a piece into the manifold behind where the plate bolts on. Nothing against "true" duals, but I've never installed them.

Charlie;

I most certanily had no intention of starting a fight. Just wanted clarification. When I built my engine I did not know much about you although Bob Criswell mentioned your name when I bought my engine block from him about ten years ago. Had I have known about you I would have gone to you for disc brakes as opposed to Plydo. I had George Asche modify my manifold. It is a true split as he welded the flapper as pictured. I do not have a crossover pipe so I do have a true split from the manifold to the tailpipe. This setup suits me as it sounds good and by listening to each pipe I can troubleshoot the front three and the rear three cylinders easily.

[pflaming]

Don: COLOR COORDINATED TOOLS! Shorts and T shirts also!

[Olddaddy]

No problem on my end, all is well.