As the V-18 251 was developed in the mid to late 60's, there has to be someone out there who can comment as to why the engine was developed. However, having done some of the math, I've come up with a point that may be significant.
With 9 throws on the 18 cylinder crank, it appears that a pair of cylinders will fire at 40 degree intervals. Note that this figure is less than the bank angle of 45 degrees. So, without the benefit of a 'proper' textbook that would refresh my memory on the mechanics of IC engines, something tells me that the 18-251 would tend to be 'smooth.'
In contrast, a V-8 engine crank having 4 throws, this would would make for firing pulses every 90 degrees. Note that the 90 degree figure is twice the bank angle of 45 degrees. Hmmm....
As for the V-10 configuration, the only V-10 IC engine that comes to mind is the example created for certain Dodge trucks and the Viper automobile.
In this case, the reason for the V-10 was to utilize an existing V-8 engien transfer (production) line and the need to meet certain hp/torque requirements.
With 9 throws on the 18 cylinder crank, it appears that a pair of cylinders will fire at 40 degree intervals. Note that this figure is less than the bank angle of 45 degrees. So, without the benefit of a 'proper' textbook that would refresh my memory on the mechanics of IC engines, something tells me that the 18-251 would tend to be 'smooth.'
In contrast, a V-8 engine crank having 4 throws, this would would make for firing pulses every 90 degrees. Note that the 90 degree figure is twice the bank angle of 45 degrees. Hmmm....
As for the V-10 configuration, the only V-10 IC engine that comes to mind is the example created for certain Dodge trucks and the Viper automobile.
In this case, the reason for the V-10 was to utilize an existing V-8 engien transfer (production) line and the need to meet certain hp/torque requirements.