Crossover pipe pros and cons...

[My52Chebby]

I'm sure the subject has been discussed before but I couldn't find reference anywhere doing a search.

X-Pipes...? vs H-Pipes...?

Size of pipe vs exhaust system pipe size...? Same or smaller...?

No Crossover vs Crossover...?

Pro? vs Cons?

What say you?

[chimp koose]

Pros....better low end torque/fuel economy. Quieter. If you are drag racing or high HP then an X pipe would be better otherwise the H pipe is usually easier especially on existing exhaust systems. Cons....slight loss of peak HP at an rpm range you are never likely to reach in a street driven car. I don't think the size of H pipe matters much just make it close to the same as your exhaust. The closer to the front of the car you put the H pipe the better. Easiest place is usually just behind the trans. It works like a collecter extender on a drag car header.

[wayne petty]

just some reading..

http://www.burnsstainless.com/techarticles.aspx

http://www.carcraft.com/techarticles/exhaust_system_installation/

in this test.. the differences are minimal in my opinion.

http://www.mustangandfords.com/how-to/engine/4376-h-x-pipe-test/

but have you seen my idea for the tuning tube?? slips into the collector flange..    picked up 10 horse power on a friend car on the dyno..




there is a big forum post about anti reversion. http://speedtalk.com/forum/viewtopic.php?f=1&t=34589

[Old Blue]

I have heard that for a flathead or a Y block you want no crossover in your exhaust system in order to have that distinctive sweet exhaust tone.

[chimp koose]

Wayne , cyclone came up with AR (anti reversion ) headers in around '82. I remember being a little dismayed at that because I was an engineering student at the time and had just thought that idea up as well. Oh well no patent or easy riches for me!As for the flathead losing its tone with the H pipe I had never thought of it before but it certainly would alter the sound.

[wayne petty]

i was sitting in the lobby of cyclone headers about that time.. there was a big conversation going on about the anti reversion header prototypes for the 440 motor homes.. that by just installing them.. they got 33 MPG in class A motor homes. .. but melted the motors.. it changed the tuning that far..  they were not going to release them as they did not want to cover all the melted motor home motors where owners would want to try them first before swapping the jetting out in the carbs..

i was also in bob kendigs shop one day with my auto shop teacher roger gates.. roger was having bob adjust the kendig carb on his dyno mule before roger put it on one of his SCTA cars.. he had several things in play back then..  bob was pizzed at predator for stealing his carb design..  oh... my auto shop teacher.. Roger Gates.. 200 MPH club member..x fuel dragster pilot.

i feel sometimes that i am the automotive version of forrest gump.

as for the tuning tube.  the guy across the street build a 14 to 1 2.2 honda H22xx.. it sounded like rapp with a big C at the front. there was so much spitting and slapping noises from the exhaust.  i drew up a drawing and handed it to him. .ask him to make several sized and diameters to try.. the first one he tossed in gave him 10 horse power on the mustang bolt on chassis dyno..  and his raspy honda no longer sounded like a raspy nasty honda.. it sounded like a healthy big block chevy..  i actually would smile when i would hear him start it up across the street..

what i figured is the 4 into 1 header has only one pulse at a time coming into the collector.. but the leading edge of that pulse is really moving in a shockwave down the pipe.. it expands into the collector and heads down the main pipe..  where the  front end of the shock wave runs out of inertia or bounces off the muffler. and zings back the other way..  running headlong into the next pulse..

i am aware of collector extensions that you spray paint a stripe on the side. make a full pass and check the burn marks..  cut it off just past the burn marks..  that is the extent of the flame from each combustion event..

if one looks at 2 stroke extractors.. this is almost what i am requesting..

the primary pipes dump the pulse and surge of expanding exhaust gasses into the collector where it can expand and slow down slightly.. it will need to escape thru the slightly smaller diameter than the collector. this speeds up the exhaust flow.. but because the tuning tube has some length to it..  the enertia of that flow as the collector empties out reduces pressure in the collector.. so there is MORE PULL on the primary tubes..  

as the surge of exhaust passes thru the tuning tube.. it can finally expand again..into the mid pipe..  any shock wave coming out speeds to the end and reflects back.. but is cored by the double pipe section. the center of the reflected pulse does not have enough pressure to push backwards thru the continous flow thru the tuning tube.. and the outside edges of the reflected pulse go into the tapered section where there is nothing to reflect off of..

i don't have a dyno or enough sensors to prove or disprove this.. i can see the exhaust flow in my mind..  i don't understand why i can see things like that.. or why i can look at a machine and understand how it works.. and when its broken.. how to fix it if not make it better.

want to have some fun..  got a steam engine laying around..  build a pressure vessel with a hatch and some high pressure injector nozzles.

place a block of sodium, posassium or lithium in it.  so the nozzles can spray water directly onto it in a very fine mist..  it should split the water into hydrogen and oxygen and release significant heat.. instantly burn the hydrogen and oxygen releasing even more heat and the ASH out of that combustion is super pressurized steam to run your steam engine..  i like the idea of a triple expansion steam engine for this ..  imagine a steam boiler without external heat source..  there is another way to do it.. requires a LOT more work..  ever seen a peroxide rocket.  same thing. build a miniature peroxide rocket vessel.. the exhaust steam to run the triple expansion engine.  use a stainless or ceramic injector like a diesel  injection pump.. or one of the neat super high pressure piezo injectors currently available to spray the high test peroxide across the platinum grid..  the trick.  high test poroxide is unstable.. tends to have issues with storage.. there is a powder to ad to water to make it.. so tiny batches can be created for use.. then dumped into the large water tank when parked for more than a short while..  could be all automated.  dart trucking learned hard in the 70s to not jack up the fright bill after they have the products in their warehouse. demanding additional payments to deliver the goods..  after it sat for a few weeks.  it got bored and left.. taking 500,000 square feet of building with it..  and every window for 7 blocks in every direction..   it was as several times louder than the  battleship salvos off the coast about the same time in the 70s.  i was about 12 miles away from dart.. and 80 miles from the battleship firing.  just  a rant..

[chimp koose]

Wayne , if I ever get to your neck of the woods in California we are going to have to go for coffee. I have a feeling you and I could exchange ideas for hours on end ! I think I became a machinist not to fix other peoples stuff but to try out some of my ideas.