Why the /6

barbee6043 said

since you mentioned the straight 6, my girlfriend has one in like a 2001 jeep ckerokee 2WD. . she has no idea what mileage it gets or can't figure it!?? is that a good motor? or what?...

Click to expand...

Great motor. Not a Jeep expert, but I heard that the Jeep 4.0 L straight six is basically unchanged from the 1950's. People love it. It is a great example of how adding modern controls (MPFI) to an engine does wonders. Too bad the slant six never similarly transitioned to the modern era, though a few guys here are working on that. I understand the small block Chevy isn't much changed from the 1955 version other than improved controls.

The 3.8L V-6 in my 2002 Chrysler minivan looks similar in many ways to my 1965 273 small block, less 2 cylinders. It still has pushrods and a rugged timing chain. Indeed, the stamped rocker arms look like the ones in later V-8 small blocks. But with modern controls and 4 sp transmission, it gets as good mileage as my 2.4L minivan. The Magnum V-6 was actually the old V-8 small block less 2 cylinders. Didn't work well (bad vibrations), so only lasted a few years. The 3.8L has a better V angle for a six. I read that a straight six is almost ideal for smoothness. That is one reason BMW people love it.