In article ,
Guy Alcala writes:
Charles Talleyrand wrote:

"Eunometic" wrote in message om...
My feeling is that knowledge of materials for engine development was
what kept engine weight up and kept down the performance of most of
these aircraft. For instance an engine of the quality of the cyclone
seen on Charles Lindbergs Spirit of St Louise would have immeasurably
improved the performance of these aircraft especially if fitted with
NACA style cowlings. It most certainly was easily buidable by the
fabrication techniwques of the day. Prior to that engines were bulky
liquid cooled models or clumsy rotaries.

Suppose someone gives them a construction manual and a prototype
of a radial engine (probably without the turbocharger) for any common
radial engine of the 1940s. Can they get the correct alloys and build to
the needed tolerances?

No, and just as importantly, they probably couldn't produce fuel of sufficiently high octane to allow it to
produce the higher power it's capable of, even if they could build the engine, and chances are the oil would be
inadequate as well (petroleum engineers with a history minor should
now weigh in).

Not a Petroleum Engineer, but some of teh vehicles in the Family
Collection date from that period (In particular, the FWD 3-5 Ton
Truck, and the Van Dorne 6-ton Tank (Renault FT). The Gasoline back
then was a lot better than most people think - it was a byproduct of
Kerosene production, and they'd basically boiled & squeexed anything
that wasn't Iso-Octane out in order to maximize the yeld for teh other
products. Of course, here aren't any good samples lying around, but
I'd place teh Octane Rating at somewhere above 80, so it wouldn't be
too dissimilar from 80/87 AVGAS. Materiels werent' a problem either -
The Engine Block, Intake Manifolds, Transmission and Transfer Case on
the FWD are Alumin(i)um, and nearly pure at that - (I took a sample to
the Materiels Lab when I was working for the World's Largest Producer
of Consumer Batteries and checked it out) much better than most
Aluminum stock these days, but probably as expesive as All Get Out.

A lot of that Octane Rating was wasted, though. Because of the need
to actually get the thing started, and because the Electric Motors of
teh day weren't up to it, the maximum Compression Ratio that was
practical to use was around 4-4.5:1. (It took 3 guys to prop a 1650
cu-in Liberty, for example, and the 400 Cu-in on the FWD is a serious
workout, even with an Impulse unit on teh Magneto to help)
Note that this wasn't just confined to the 1910-1920s - many engines
used flywheel starter systems, either hand-cranked or electrically
driven, to store up enough energy to get the bit engines turned over.

The big drawbacks to producing a high-powered engine at that time were
Carburetion and Ignition. Carburetoes were simple in the extreme, adn
weren't very good at atomizing fuel, or at adjusting to the varying
air densities encountered by an airplane engine.
Ignition systems were crude - they all worked with extremely high
voltage, (70 Kvolts or so), to try to get the strongest spark they
could, with the Spark Plugs that existed at that time. That's all
well and good, but there weren't any good insulators available. This
led to internal breakdowns in the Magnetos, and arcing and shorting of
the plug leads. It's bad enough at Sea Level, and it's horrid at high
altitude, where the dielectric properties of the air are much worse.
(Heat tolerance by these materials was poor, as well.) Insulators
were ceramic, Natural Rubber, and Mica. It took the development of
Plastics in the late 1920s-early 1930s (Most Notably Bakelite and
Formica) to produce reliable high-power Ignition Systems.


If you want to postulate time
travel for a one-time deal, fine, but if you're looking for something that could actually be produced 20 years
earlier and be supported for the long term, it just ain't gonna happen.

Concur - there were a lot of steps that had to be made before you
could build anything more advanced than they were. In fact, teh Forst
World War, and the technology race that it spawned was the major
driver for those advances.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster