Originally the Hemi's of the past with the hemisperical head had more room to put larger intake and exhaust valves. An engines ability to breathe has allot to do with power output. They were able to squeeze more power out especially when you boosted it with a blower for drag racing. The new hemi's are somewhat that way but you are restricted with compression and trying to run regular gas.

The new Ford triton in the 2004 F-150 has 3 valves per cylinder. They have raised the HP rating on the triton but the hemi still puts out more raw HP. The triton is 5.4 while the hemi is 5.7. I haven't compared power and torque curves. I get about 14MPG with my 2002 F-250SD and 5.4 with 2 valves per cylinder. Chief said to expect 12MPG with a 1/2 Dodge. I'm dragging more weight around with a 3/4 ton but still get an edge on mileage. That sounds about right!

Reply

Quote Reply

Digg It

Del.icio.us