What's with all the flat fueling spots on the new bikes? - Page 4

 J. Clarke wrote:


Oh, he's talking about what happened 40 years ago?  That was not
clear.  Ancient history.

 dizzy wrote:

And in a wonderful example of "correlation isn't always
causation" - assuming we're talking about the 1970 Clean
Air Act here, the drop in rated horsepower around that
same time was almost entirely coincidental.  Remember, this
act had no real impact on American cars until the 1972 *model*
year - which completely by coincidence was also the year that
manufacturers in the U.S. switched from quoting SAE *gross*
horsepower measurements to the much more realistic SAE *net*
horsepower.  For one example, the Chrysler 426 Hemi engine
was listed as providing "425 HP" in 1971, but dropped to a
rating of 375 (SAE net) HP in 1972, with NO changes whatsoever
to the engine.  In short, the Clean Air Act had basically zero real
impact on the power of engines at the time.

Soon after this in that same decade, of course, engine horsepower
DID take a significant hit, but again it had nothing to do with the
emission controls - it was the result of the manufacturers suddenly having
to chase fuel economy rather that flat-out performance, owing
to consumer preferences changing sharply following the Arab oil
embargoes of 1973-74 and the resulting spiking of gasoline prices.

Bob M.

 Bob Myers wrote:


Yes, I knew about the change in rating system, to "net".  However, if
you are right about the Hemi, I believe it was the exception.  Most of
the hot engines disappeared after 1971, and 1972 had only
lower-compression and otherwise detuned motors.


Well, the detuning started before 73, for sure.

 
The law became effective with the 1971 models.  Chevy even brought out the
new bodied Camero as a "70 1/2" to avoid the restrictions.

An FDA chemist explained how a car that got 18 mpg one year but only 12 mpg
the next somehow made less pollution.  Seems that NO2 was a major buggyboo
in LA - mixes with fog to make nitric acid - but actually comes from
compressing and heating air, hot from burning gasoline per se.  Nor is it a
problem where it rains much because rain dilutes it and plants love it.  But
all the smog laws started in LA so congress in its usual wisdom required car
makers to reduce compression ratios in order to make less NO2 even though
that meant the cars used a lot more gas.

None of us are as dumb as all of us!

 

Zed 1000
OMF# 19