[DeTomaso] Longchamp header tech

[Daniel C Jones]

> Here's the question: Last time I read about tube length, long tubes were
> for torque and power in the 1500-5000 rpm band (depending on thickness and
> length) while shorties were for high rpm.

Shorties are generally for fitment.  Long tube headers are generally better
across most of the RPM range.

> But looking at a test on the web, the clipsters and the long tube are almost
> the same on both torque and HP.

I'd have to see the test and know the specifics of the engine and the headers
tested.  If you know what to do, it's easy to bias the outcome.  For instance,
a restrictive muffler can negate the differences between certain headers and
the type (design) of muffler can alter the apparent header collector
dimensions.
In my testing of Pantera headers versus long tube Mustang headers on a 351C and
408C engines equipped with both 4V and CHI heads, the difference in peak power
on the street cammed engines was minor but the long tubes made better
peak torque
and were better in the low and mid RPM ranges, providing more area under the
curve.  Vizard's testing indicated that bank separated 4-into-1 headers show
similar performance for primary lengths between 24 and 36 inches.  Things are
more sensitive to collector lengths (and diameter), as well as the mufflers.

> I can't buy Cleveland headers that will just fit, I probably have to modify
> a bit. In the spirit of minimizing the modifications I surfed Summit and saw
> something that didn't exist last time I bought headers: clipsters, something
> between the normal long tube headers and the shorties. I think they would be
> a lot easier to fit.

I only see Clippsters for Windsors.  In addition to the usual Mustang headers,
look for Australian Ford headers, street rod headers, engine swap headers,
truck headers, 351C tri-y designs, block huggers, Cobra replica headers, etc.
Swap headers for the narrow shock tower 1965 and 1966 Mustangs might be of
interest.  There are a couple of designs.  FPA (Ford Power Applications) has
a 4-into-1:

 http://www.fordpowertrain.com/FPAindex/headers1.htm

There are a couple of companies making cross-over headers that have one tube
from each bank

 http://www.bacomatic.org/~dw/engine/fordv8/cleve/cleve.htm

The ones I have are from Tubular Automotive.  These allow the headers to fit
in a tight engine bay.

Castle in Australia makes an interesting tri-y 351C header:

 http://www.network54.com/Forum/119419/thread/1073850915/Tri-Y+headers-

Pacemaker is also in Australia:

 http://www.pacemaker.com.au/ford_falcon_v8_xr-xf.html

Not sure if Doug Thorley makes tri-ys for Clevelands but it would be worth
checking.  Sanderson makes block hugger, truck (351M/400 have 2V ports) and
street rod headers:

 http://www.sandersonheaders.com/Ford-Cleveland-and-Midland-351C-400M

Dan Jones