I wonder if there isn't some misunderstanding of how tuned exhaust systems work. I see people using the term 'backpressure' to describe flow characteristics in exhaust pipes.



My understanding is that when an exhaust system is properly sized, the exhaust gas pulses from the cylinders will actually cause a negative pressure wave to reach the exhaust valve when it opens. Of course, this negative wave will scavenge exhaust gas from the cylinder and improve power.



Exhaust pipe size is selected by engine size and cam characteristics. If a cam is tuned for power in the 2000-4000 RPM range, the exhaust pipe should be tuned for that RPM, too.



There is a formula somewhere on the 'net that helps pick pipe size. I think that 1 7/8" or 2" is good for 292's. Things like exhaust crossovers also have an effect.



Also, my Mustang V8 came from the factory with different sized mufflers (and an exhaust crossover). The different sized mufflers prevents harmonics from developing between the mufflers (causing a 'droning' sound at certain RPMs).



Also, Vizard's work reveals that the size of the crossover pipe should be smaller than the exhaust pipe. Finally, the tailpipes should be smaller than the exhaust pipes.



But I might have that wrong.

Best regards,



Paul Menten

Meridian, Idaho

Dan,

       If I understand you correctly, you're asking if the crossover would act the same as an "H" or "X" pipe? It would but the crosssection is so small that it wouldn't have much effect. And, as you mentioned, opening it will raise the intake floor temperature. This isn't necessarily a bad thing in the midwest, in cold weather, but hurts on the dragstrip. The "X" pipe seems to be the best on a dyno, while the "H" pipe is easiest to install. Both help.   

Frank/Rebop

Bristol, In ( by Elkhart) 

The addition of a H-Pipe into the exhaust system will reduce the ‘per side’ exhaust pressure which in turn would reduce any tendency for the exhaust to be using the crossover in the intake manifold as a pressure release.  With this in mind, the intake manifold can potentially see a slight drop in temperature with the installation of a H-Pipe or anything else in the exhaust system that would alleviate some of the exhaust back pressure.

Lorena, Texas (South of Waco)

Re: the original tread (H-pipe/exhaust tone);



I'm surprised no one mentioned the intake manifold crossover passage. Just restricting it slightly with a truck gasket produces a noticeable change in exhaust tone/volume. Unfortunately, any increase in power that might be expected from a wide open passage (as from the "H" pipe) would likely be nullified by the higher manifold/mixture temp?

6 VOLTS/POS. GRD. NW INDIANA

California has a really nice Veterans home and it's not far from John Mummerts either.

My kids are scoping out a spot for me...Gerry

Lake Forest California  5th inf 77 Armor Div. VN 68/69

If you put your town and state in your signature

help might be closer than you think.

can the wheel chairs have y-blocks in them

moz. geelong victoria australia.

graduate 1980, bus, truck, car, hot rod, boat, submarine, hovercraft, hydrafoil, firetruck, mobile home, jet, helicopter, cruise ship, motorcycle, bicycle, santa's sleigh, clock, alloy bullbar, alloy fuel tank, lens, dr who's tardis, matter - anti matter warp drive buffer & y-block lover

As Frank says,I don't see that it would make any difference.Mine are straight and welded in about 8" ahead of the mufflers.Works great.

Don't have to go to the Old Folks Home.The Missouri Veterans Home is only about 30 miles from me and I've already got my reservation in!!!!!

 

Paul,

Boonville,MO

Scott,

         Doesn't matter, the object is to allow each pulse two mufflers or twice the volume to exhaust to. Bends don't make a difference to the pulse.

Frank/Rebop

Bristol, In ( by Elkhart) 

I was always told to keep the wire in a sealed bag with dessicant when in occasional use. I've also been told you can vent a little Argon gas into the bag to remove the oxygen. This will help prevent the oxidation. Also a local guy showed me how he clips a piece of Scothbrite just past the wire roller so it cleans the wire as it passes through. Seemed to work for him. Chuck in NH

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

Ted,

Whatever the reason was,the new wire sure worked better.It could well have a little rust or deteriorated flux,or both.Anyway,I have a good excuse for the horrible looking welds.

 

Paul,

Boonville,MO