[DML] Re: Torque From Displacement

["David Teitelbaum" <jtrealty@xxxxxxxxxxx>]

I agree with "No replacement for displacement". Another old
hot-rodder's trick which adds a lot of torque is to add a "stroker"
crank. By effectively lenghtening the "arm" you gain more mechanical
advantage and add a lot of low end torque while increasing the
displacement. Other ways to increase low end torque include a
different cam and/or retarding the cam timing, bringing the ignition
advance in quicker, improving the breathing by porting, polishing,
larger valves. larger exhaust and headers. On an automatic you can
change the stall speed on the torque converter. All of this is moot on
a Delorean because the drivetrain is power-limited by the
transmission. As I mentioned in past posts we had Fred Dellis of
Legend Industries speak at a dinner and he said they could get all the
power they needed out of a modified PRV, their problem was the
transmission. Future plans were to find another supplier for the
transmissions. Besides the limitations of the Renault transmissions
they found it very hard to deal with the French. BTW it isn't the high
revs, it is the feet per second of the pistons. At higher revolutions
the piston FPS speeds start to get ridiculous. You don't get any
longevity. This is what happens in 2 strokes. You have incredible
speeds to get the power but limited life. BTW 2 stokes don't have
valve springs so they don't have problems with spring pressures and
valve float. At such high speeds you have a hard time getting complete
combustion so meeting air quality standards is impossible. Electric
motors have a very flat torque curve. This is what makes them
attractive in hybrids and electric vehicles.
David Teitelbaum
vin 10757



--- In dmcnews@xxxxxxxxxxxxxxx, "content22207" <brobertson@xxxx> wrote:
> Regarding your last sentence: We've got a saying down South --
> "There's no replacement for displacement."
> 
> The single best way to get Torque out of your gasoline engine is to
> increase cylinder sizes. My 460's have more power *AT IDLE* (500 RPM)
> than some small engines have at speed. Max Torque is pumped out
> somewhere in the neighborhood of 2-2,500 RPM. They've never seen 4,000
> RPM even with a telescope. That's one secret to their longevity --
> high rev'ing is very hard on an engine. So too is force feeding it air.
> 
> Note that my 5,000 lbs Lincolns can not only propel themselves 0-60
> MPH in less than 9 seconds, but they have enough Torque to spare to
> pull an additional 5,000 lbs behind (Class III). A trailer does cut
> into acceleration somewhat...
> 
> Bill Robertson
> #5939
> 
> >--- In dmcnews@xxxxxxxxxxxxxxx, Michael T Twigger <marktwigger@xxxx>
> wrote:
> > True mainly because many stock 4cylinders
> > are made for everyday use where you need torque to work with, and not
> > race with.
> > But trying to increase hp and torque you have to change cams or
computer
> > settings that control the valve timing to enable the engine to
> > reach much higher rpms for hp. And when you do that the engines
> > peak torque is at a higher rpm. Even though the rpm difference between
> > the
> > small engines to the much lager one isn't much. The difference in
torque
> > is
> > huge. There is no way you could get the same amount of torque at the
> same
> > rpm out of
> > a N/A 2.0L 4 as with a 5.7 LS1.
> > 
> > MT
> >




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