[Land-speed] Multiple Engines

Skip Higginbotham saltrat at pahrump.com
Thu Mar 25 15:30:42 MST 2010

I think so too. So, if I understand, the rear crank effectively stays 
loaded and never unloads as much as it would have on it's own. As you 
point out, the cycle is therefore shorter in amplitude so loads are 
much less than they would be if the engines fired together although 
the total load is higher. It would be interesting to know actually 
what doubling the frequency might do but it doesn't seem to matter 
with the loads reduced from worst case.
Thanks Kirk.

At 06:16 PM 3/24/2010, Kirkwood wrote:
>It seems to me you may be smoothing out your torsional frequency. As Dave
>mentioned the cylinder pressure is greatest somewhere around 14 degrees. If
>you index the motors 45 degrees the pressure peak (on the rear motor) will
>occur every 22 degrees. In addition the rear crank is preloaded with the
>torque input of the front engine. That means the rear crank never returns to
>its single engine torque value. You have decreased the amplitude of the
>torque input and doubled its frequency.  For example, let's say one firing
>impulse results in a pressure of 1,000 psi and bleeds down to something like
>500 lbs due to overlap from the next firing cylinder. With the front engine
>introducing a torque peak 22 degrees later the crank never returns to its
>lowest state of a single motor. Torque amplitude is less and frequency
>doubles. The only issue I see is doubling frequency moves anything closer to
>destructive harmonics, but is it germane here? I think John Burk might be

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