Re: Bellanger vs. the \"other\" headers
I've got a set of used Belangers on the way-just in case I need them. (?)
Looking at photos of Belangers, I see that apparently that brand doesn't pay much attention to sequencing the primary pipes as they come into the collectors on each side in a
rotational firing pattern. As I've noticed with other brands of headers offered for Vipers.
Meaning having each cylinder bank's header primary tubing enter the collector per
firing order for that bank, rather than just arranged by cylinder progression front to back, next to each other in the collector.
Or said another way, to end up with one primary next to one that's just fired on a bank, rather than having another tube in between them, or worse in the other sub-collector on the Belangers.
Something like a Gatling gun effect visually.
On the Belangers, I count what seems to be 3 examples per side of the rotational order jumping back and forth across the two 3 into 1 and 2 into 1 collectors ahead of the final collector.
For example the passenger side fires in this order: 10 4 6 8 2, but the primary pipes have cylinder #10 in a different sub-collector than cylinder #4, #4 IS next to #6, but the next firing, #8, jumps to other sub-collector, then jumps back again to the 3 into 1 collector for the cyl #2 firing.
You'd have to have at least one firing sequence out of sync per side with a Tri Y header's dual sub-collectors on each side, but there seems to be 3 per side. 5 into 1 headers though only have one collector per side.
I was going to ask a header builder about that when I order some exhaust pipe flanges soon, but after doing a quick internet search, it seems that there is indeed something to arranging the primaries per their firing order on that bank.
Arranging the tubes to fire rotationally adds to the scavenging capabilities. The exhaust gas exiting one tube, passing across the opening of the tube directly beside it, creates more suction on that tube than it would on a tube on the opposite side of the collector. For example.
A lack of space under a Viper may be a factor. Or, maybe once an engine's running, the firing sequence doesn't have to be thought of starting with the front cylinder on each side, since it's turning over more than once, - which might throw off the sequence count..
I just thought I'd add what I've been taking a look at to this header conversation. There seems to be considerable search results on the subject, with some healthy HP gains claimed.
FWIW
