[TML] Molding Ships

[Christopher Hilton]

shadow at shadowgard.com wrote:
> On 2 Oct 2007 at 16:54, Charles Prevatte wrote:

[snippage]

>  
>> Look at the engine in the Wright brothers plane.  Today we have better and
>> more powerfull engines in leaf blowers and lawnmowers, but the basic
>> principle is exactly the same.  No new concepts to learn, just refinements.
> 
> Too many of the things you want to build require new materials. Like 
> the turbine engines in the copter and the M1A1 tank.
> 

Just to put a further edge on your point Leonard The big advances in 
piston engine power output from World War I to Vietnam weren't made in 
engines at all. In the 1930's analysis showed that engine power was a 
function of compression ratio for piston engines. Changing the 
compression ratio is a macroscopic process that happens at the machine 
shop. It could have been done in the 1930's but the resulting engines 
wouldn't last very long given the fuels that were available. In World 
War I high octane gas was either precious or non-existant. It was 
available to racing planes from the the 1930's through World War II and 
Korea but it really became available in the late 1950's  ~ early 1960's. 
That allowed the manufacturers to bump the compression ratio to 11.0:1 
which was typical for a high performance 1960's American Muscle car.

The next big advancement in engine technology came about because of the 
pollution controls of the mid 1970's. At first this was a net loss 
because the automakers saddled their engines with unreliable mechanical 
feedback control systems that required more adjustment and tuning than 
their owners could give. To solve these problems the manufactures moved 
from trying to tame emissions in carburetter engines by moving to 
electronics in fuel injection and ignition. Couple that with sensors and 
you've got the opportunity make big power and have a "clean engine" by 
varying the operating parameters or tuning of the motors on the fly. Add 
detonation or knock sensors and you can improve compression ratio even 
on poor quality gasoline.

-- Chris

-- 
       __o          "All I was doing was trying to get home from work."
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Christopher Sean Hilton                    <chris | at | vindaloo.com>
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