crossover tube
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From: Santa Clarita
crossover tube
Can anyone tell me the benefit of running a crossover tube on the exhaust? I'm trying to figure out where to install one. The transmission support runs across the frame where it should be and the driveline is behind that.
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From: Littleton, New Hampshire
My opinion is that unless you are going racing or trying to wring every bit of performance out of the engine, a crossover tube is a waste of time and effort. I know they are supposed to smooth out the exhaust pulses and make the exhaust scavenge better but if your truck is a cruiser like mine you won't notice the difference. I had a 65 Mustang with HP289 that came with tri-y headers and a crossover tube but when I replaced the exhaust I deleted the tube. I could not tell any difference in the everyday performance of the engine and the exhaust even sounded better with the pulses uneven. If I had taken it to the dragstrip I might have been able to see a drop off in performance but it was not enough that it was noticeable in everyday driving. I'm sure there are others that will tell you that you should have the crossover tube so this is only an opinion not based on scientific facts... 
Vern
Vern
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From: Auburndale, Florida
I think that Vern is basically on the money. For street it probably doesn't make all that much difference but I guess that would also depend on the engine. You can do a search and there should be several hits regarding placement but one that sticks in my mind to determine where to put the tube is:
Paint the collectors and exahust pipes with a paint that will burn a little - go and run the car hard and then see where the paint is burned or burned off. That's where the cross-over goes. Not very scientific but easy and quite practical. If I've remembered wrong I'm sure someone will correct me (and no offense will be taken) but I think that's the jist of it.
OilLeaks
Paint the collectors and exahust pipes with a paint that will burn a little - go and run the car hard and then see where the paint is burned or burned off. That's where the cross-over goes. Not very scientific but easy and quite practical. If I've remembered wrong I'm sure someone will correct me (and no offense will be taken) but I think that's the jist of it.
OilLeaks
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Thanks for the advice. I've heard putting an X pipe or H pipe is beneficial, however I think it applies to the newer 5.0's. I did some research and oil leaks is right, the paint works on locating the correct spot (LOL) I also read a crayon can be used by drawing a line along the pipe and then watching the location where the crayon starts to melt first. I think I'll stick with my straight pipes. I'm not looking to increase ET's on the track, at least not with my truck. I heard the crossover tube changes the sound of the exhaust and reduces retonation on the interior. That's what I'm curious about, if it really makes a difference or not?
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From: Littleton, New Hampshire
Originally Posted by imlowr2
I heard the crossover tube changes the sound of the exhaust and reduces retonation on the interior. That's what I'm curious about, if it really makes a difference or not?
Vern
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From: Auburndale, Florida
I've also heard that the crossover gives a slightly mellower tone. Not sure about interior resonance but it's also supposed to help the motor yield a little more torque. Again if you're not worried about ET at the track then unless you just like welding exhaust tubing it may not be worth all that much. On my 51 with a flathead V8 I'm running duallys but the manifold does have a small crossover built into it (typical for flatty manifolds) and I believe that was to help the carbs warm up. Back in the day it was typically blocked off on "race" engines and its said to give the exhaust note a little more "bark".
OilLeaks
OilLeaks
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From: Durham NC
Easiest way to determine if a crossover will be a benefit: write down the firing order of your engine in a column repeating twice (to see what happens as the order goes from the last back to the first). Next to each cylinder number indicate if that cylinder is in the left or right bank of the engine. Now read down the list of lefts and rights. Virtually all V-8s will not alternate L-R, the more of the same bank in a row the more your engine will benefit from a crossover. The same system is used to determine which cylinders should not be paired in Tri-Y headers.
It won't be "perfect" design, but an H type crossover can be added to a set of duals quite easily by determining where before the mufflers you have a straight shot across between the pipes and adding a crossover pipe a diameter larger than the dual pipes at that point, Put in a bend in the middle to clear the driveline and oval the ends to match the diameter of the main pipes.
It won't be "perfect" design, but an H type crossover can be added to a set of duals quite easily by determining where before the mufflers you have a straight shot across between the pipes and adding a crossover pipe a diameter larger than the dual pipes at that point, Put in a bend in the middle to clear the driveline and oval the ends to match the diameter of the main pipes.
Last edited by AXracer; Jan 14, 2006 at 12:49 PM.
