how much would this help?

[Anonymous]

Just curious: As an alternative to a header, how much would this (dual exhaust using 2 stock mufflers) help the flow of exhaust? It has to be some improvement over the stock manifold, right? Any gain or loss in HP?

 

[rbohm]

8) to a certain extent, any reduction in backpressure aids performance. as to how much the mod shown in the pic will help i am not sure as i have never seen that mod done before.

 

[Mustangaroo]

Think it's more effort than it's worth! Try ebay auction for headers, I found mine new in the box (Clifford) for only $115.00 on ebay. I was looking for a used header for my son's aussie 2V project and had about four to pick from over a two month period on ebay and here at the Ford Six for sale fourm found a set unused for $80.00, and don't forget to post in the wanted fourm! BTW I was looking for 3.55 gears and ended up finding 8" inch 3.55 gears in the pumpkin set up for only $50.00 including shipping! Jsut look around on the net! I have found that you can find almost anything your looking for, but it may take looking everyday for a month!

 

[Anonymous]

The first time I saw it was when MustangSix posted it. It looks very interesting. Might consider trying it if ya'll think it would be worth the hassle of fabricating it. (trying to avoid headers!! )


On a side note, why would you seem to lose HP when the exhaust pipe is cut short. While redoing the exh. system a few years back, I had to cut the pipe underneath the front passenger side door until I could get it to an exhaust shop. This drastically reduced power until a new longer pipe was installed. What caused this?

 

[Anlushac11]

8)

No back pressure can lead to overscavenging which pulls fuel and air out into exhaust, means less to burn.

An old trick on headers and straight pipes was to paint the pipe with header paint. Then start can and run for about ten minutes. Pull pipe off and look for the burned spot. Cant remember what you do after that.

 

[CZLN6]

Howdy Back Falcon 64:

It may help some and it looks cool as a ditch digger knee's in December. If you could figure a way to split the thing in the middle, separating the 3/4 siamized port in the head and the manifold, that would be better. Either way, it would likely reduce back pressure in the exhaust manifold, but without seperation, it would likely disrupt flow. The long primary tubes of a header system actually enhance the pulses.

The problem with a log manifold is the tight angle turns the exhaust pulses have to make both inside the head exhaust port and exiting the head and hitting the log. Exhaust pulses don't like to turn. Each hard turn disrupts pulse magnitude and velocity, which weakens scavanging and impedes flow. Picture this- the exhaust pulse has left the #1 cylinder and is head out the port. Oops, it hits the top of the exhaust port and has to turn down. Oops, it makes the turn then hits the exhaust log and has to turn back. Oops, it crashes into the # 6 exhaust pluse coming forward. I use the #s 1 & 6 cylinders because they are 180 degrees opposite, and should help each other. Headers elininate the 2nd and 3rd Oops'.

The exhaust ports are as bad on this head as the intake ports are good.

The advantages of adding a dual exhaust system is dependent on how restrictive your current system is. I'm wondering if a bifricated exhaust, cylinders 1,2,3, and 4,5,6, would ever generated enough heat to flow good and burn out the H2o resulting from condensation. Inner pipe diameter would be a factor.

Personally, I prefer a ported exhaust manifold, into a 2" system to a turbo
type muffler with one pipe in and two out, to give the look and sound of duals. It is a cheaper, lighter system, and possibly more efficient then a split log manifold and duals. Port match the individual window to an exhaust manifold, or slightly larger, and open the outlet to a full 2", but leave a ridge for the header pipe fire wall to butt against.

People who have done the split log duals report a great six rap, with glass packs.

If you go that way, be sure to report the results. Take a 30 mph to 60 mph timing in high gear, before and after.

Happy New Year.

Adios, David

 

[StrangeRanger]

On a side note, why would you seem to lose HP when the exhaust pipe is cut short. While redoing the exh. system a few years back, I had to cut the pipe underneath the front passenger side door until I could get it to an exhaust shop. This drastically reduced power until a new longer pipe was installed. What caused this?

The longer the pipes, the lower the RPM for which the exhaust system is tuned. Very short pipes work at very high RPM. It's all in Scientific Design of Exhaust and Intake Systems by Philip H. Smith, available from www.rb.com

 

[Anonymous]

There was one of those manifolds on EBAY a good while back. I do notthink it was fabricated buy was made that way. So someone makes or made them at one time. The person that has it was selling some contents of a old speed shop so it may be obsolete now..

Darin

 

[addo]

An old trick on headers and straight pipes was to paint the pipe with header paint. Then start can and run for about ten minutes. Pull pipe off and look for the burned spot. Cant remember what you do after that.

That's where the crossover goes on a V8 system.