Steve,
 I rolled out the cowl with an english wheel since those photos were
taken.
I talked with Everett Hatch about a year before his accident, and took
some
advice from him on materials for the cowl. It's .050 5000 series aluminum,
the spinner is 16" dia, the prop hub is 44" from the firewall, as opposed
to
39" for the stock RV-4, and the firewall is 1" higher, and 4"
deeper(lower)
than stock. Radiator and oil cooler are slung beneath the wing spar.

Pictured are the station buck and english wheel, and the other picture is
the first attempt at the top of the engine cowl. The later, successful top
part was made out of two halves, rather than one piece.


Brian Trubee

Brian--kudos on that cowl.  Only folks directly involved in one of those
projects knows how much is involved.   As Everett probably noted to you, we
built an all-aluminum one for the RV-3 using multiple pieces all welded
together then worked smooth.  Took a long time.  But as you know, on a very
tightly cowled engine the exhaust ports are potential cutting torches in
close proximity and pointed directlly at the cowl, so with a plastic cowl
its always a higher hazard. Have always been scared spitless of the lethal
potential of engine-related fires.  Other than time and complelxity to build
the aluminum cowl, the negative surprisingly was that it came out quite a
bit heavier than a fiberglass counterpart.  How much does yours weigh with
all related hardware installed?

We flew the rotary RV-4 for years with two different types of fiberglass
cowls so thought I would try that again on the new RV-3 under construction
to save some weight.  Used the aluminum cowl as a starting point  the
current fiberglass cowl and will have to build pipe enclosure and standoff
heat shields from .016 stainless.  Another time consuming project in itself
as the pipes snake around various bits.  You have any photos of your
cowl/spinner installed?  Did you know how to wheel and work compound curve
aluminum before starting the project?

Steve Beckham

Brian I know somebody is in the market for a cowl. Are you interested
in making another one for money?

Paul Lamar