tuned exhaust for a lycoming 0320

I'm just having more fun than should be legal and it probably isn't if I
look far enough into the County, State and Federal statues, but I am
never-the-less. I have pretty much followed the Cafe numbers for header
length and the 4-into-one collector. Keeping in mind friendship to my
neighbors, I also included a muffler. I purchased the collector and muffler
from Barnes Stainless and will be purchasing the header tubing, 321SS from
the same source in all likelyhood. A/C Spruce has the tubing listed at
$8.75/ft.
I've made up some PVC headers complete with flanges glued on and am heating
the PVC with a heat gun and bending them until I get the pipes where I want
them. The plan then is to take the bent up PVC to a muffler shop that has a
mandrel tube bender and have them bend up the expensive 321 SS tubing. I
plan on welding in some of the 3-bolt ball fittings to both ease the
stresses and make installation and removal easier.
My plan is to install the stock exhaust, do a hover and check the MP and
then quickly change exhaust systems and repeat. I'm hoping to see a MP
improvement.
I've had this plan in my "Round Toit" list every since I read the Cafe
study.

Dang I sure do like the experimental category. No bureacrats in the way.

Stu

Better scavenging and more power means more fuel flow... - TANSTAAFL

denny

"Denny" wrote in message
...
Better scavenging and more power means more fuel flow...

I believe that depends on a number of variables. Lower flow losses means
higher efficiency. Higher efficiency can mean lower fuel flow at a given power
output, or it can mean higher horsepower output at the same or greater fuel
flow.

Vaughn

"Denny" wrote in message
...
Better scavenging and more power means more fuel flow... - TANSTAAFL

denny
When I'm pulling on the collective, looking for more torque, (rpm is
constant in my helicopter) there are times when fuel flow doesn't even come
into the equation. I will still normally only use the power that I need,
but when the density altitude starts climbing up a power reserve is worth a
bunch of money.]
Stu