Re: 304/290/200R4 - now V8 Fuel Mileage

[Tom Jennings <tomj@xxxxxxx>]

On Mon, 9 May 2005, Sandwich Maker wrote:

I find this thread interesting too (and sorry if I helped it veer
off) it all applies to all AMC motors.

> 'lugging' it is not a good idea.
>
> generally, your engine will be most efficient near its torque peak.
> if you want great highway mileage, you want a cam that moves that peak
> down toward your highway rpm.

As I see it, there's three things in tension: lower RPMs keeps
frictional losses low, but you must have enough to makde decent
torque and HP.  1600 rpm sounds great, but it's impractical to
make HP there. 2000 - 2500 is probably a good target RPM for
torque peak, probably line up all the hard parts
(trans/OD/axle/tires) then have a cam ground to put it spot on the
target RPM/MPH.

But first you can take really big hints from what the factory did;
little americans with manual trans and steep axles, see where
those cams are ground and start there.

Somewhere I made a big table of all the AMC six cam factory grinds
(60's - 70's) but I can't find it!