Hammer
TDR MEMBER
Jim,,I'll not say or deny some can not make power in orbit zone(4000 rpm or greater)but,my original question will still stand,,How do you take a motor with a valve train that designed to make max power and torque below 4000 and keep it out of valve float,,We all,and I'd imagine you have also,seen the many dyno sheets available to us and know that from 3400 up in a 12 valve power and torque drop significantly,ever wonder why?,,Valve float is something you'll never hear or see(unless you have a cover designed to see into or read it on a engine dyno),,Of course Piers's truck is expected to go beyond the relm of our ranges with him being one at the forefront of technology for these motors,,To shift at 4300,unless your a clutz with the swift stick,it still should be running way into float range and killin power,,Newer motors(24 valvers) are designed to run higher rpm's and still have tendencies to drop off significantly in the higher rpm's,,The addition of a 4k kit is helpfull to the older trucks to help facilitate higher rpm fueling along with a better camshaft,but,without a better valve train how can they say they make power up there??,,Its a proven fact that these motors fall off up top and the higher you go the more they drop and the faster,,Which led me to my question... ...
P. S. -In a recent flame job on me even Joe D tells you how inefficent these motors are at higher rpms... ... . Consider the technical theory of fueling vs. rpm in a diesel. The injector flows fuel per time. It can flow only half as much at 4000 rpm as at 2000. To make high rpm horsepower, you must use higher flow injectors. The bigger holes give poor atomization, a reason for the huge black smoke clouds. Thus, you may get fuel in at 4000, but only some of it burns. Then you use 100 psi of boost to increase the tornado in the cylinder to help atomize the fuel and burn it. At 6000 rpm the situation is only worse. The time for fuel addition gets shorter and shorter as rpm increases, and the time available for burning to be initiated and completed, while the piston is positioned correctly in its stroke, is also reduced. Thus, while torque x rpm = hp, in a diesel engine it is hard to maintain decent torque (effective fueling) at high rpm, vs. what can be achieved with that injector at lower rpm--assuming decent fuel atomization.
P. S. -In a recent flame job on me even Joe D tells you how inefficent these motors are at higher rpms... ... . Consider the technical theory of fueling vs. rpm in a diesel. The injector flows fuel per time. It can flow only half as much at 4000 rpm as at 2000. To make high rpm horsepower, you must use higher flow injectors. The bigger holes give poor atomization, a reason for the huge black smoke clouds. Thus, you may get fuel in at 4000, but only some of it burns. Then you use 100 psi of boost to increase the tornado in the cylinder to help atomize the fuel and burn it. At 6000 rpm the situation is only worse. The time for fuel addition gets shorter and shorter as rpm increases, and the time available for burning to be initiated and completed, while the piston is positioned correctly in its stroke, is also reduced. Thus, while torque x rpm = hp, in a diesel engine it is hard to maintain decent torque (effective fueling) at high rpm, vs. what can be achieved with that injector at lower rpm--assuming decent fuel atomization.