Jim Parent wrote:
> Typical performance Ford books note that 1 5/8" primary tube headers
> are a fairly close match to the port size and should work just fine.
> If SS's are 1 1/2" I'd guess that's close enought so that it won't be
> your biggest issue. BTW, the same books normally note that primary
> tubes oughta be about 30" to 40" long and that both selections are not
> an exact science.
Jim,
Actually, header designs are an exact science. Especially if you want the low
pressure wave in one exhaust port to help extract the next cylinder. Ideally,
they work like waves, one tube's low pressure helping extract the next, and so
on through the next cycle. This is the main purpose (other than diameter) for
headers. This extraction aid only works over a narrow rpm range, so they are
"tuned" for a specific engine and use. Unfortunately, only the pro's can afford
a different set for each race. The Tiger has little room for this, anyway, so I
wouldn't sweat any "optimization".
Steve
--
Steve Laifman < One first kiss, >
B9472289 < one first love, and >
< one first win, is all >
< you get in this life. >
_/_/_/_/_/_/_/
_/ _/_/_/ _/_/_/ _/
_/ _/ _/ _/ _/ _/ _/_/_/_/
_/ _/ _/ _/ _/ _/ _/
_/_/_/_/_/__/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
_/
_/_/_/
|