Turbo header design

[FHPREMACH at aol.com]

In a message dated 1/6/99 4:10:50 PM Pacific Standard Time,
darkmonahue at awwwsome.com writes:

<<This is easily done with an inline four having a 1-3-4-2 firing order,
as you just pair cyl's 1-4 and 2-3 together.  Commonly done in NA
headers and OEM manifolds too.  However, true 180 degree headers on a V8
typically take up a lot of space.>>

Yes, and fabrication is a nightmare. fitting them into a car with any
accesories is a real challenge unless you try to reverse the intake and exaust
like some of the Indy V8's that Ford did years ago. Now think about the fun of
trying to run TPI to that mess.

<< Almost sounds like an exotic foreign supercar (or a flat-crank V8, come
 to think of it) >>
As I remember from a lot of engine research, flat cranks and 180 degree
headers are great for max horsepower, at the expense of powerband width. I
also recall there being a major problem with intake resonance and reversion
with these systems. On a turbo it might not be a problem. but I would suspect
that a good short free flowing pair if 4 into 1 headers with an appropriate
size collector merging the pair into the turbo would be fine. Go look at some
old Indy Offenhauser Turbo 4 cylinders, some of those were simply a series of
exaust bends emerging from the heads and right into a log type manifold to the
turbo. Very simple, and very tight packaging.
Fred Harmon