Re: [Amc-list] Early 80's 4-cyl bellhousing

[adh@xxxxxxxxxxxxxxxxx (Sandwich Maker)]

" From: Frank Swygert <farna@xxxxxxx>
" 
" Yes, the 2.5L was paired with a T-5, but the trans and rear axle
" gearing were set up for it also.  Anyone who had one will probably
" tell you fifth gear was useless unless you were on the interstate
" running 60+ with a light load and in pretty level terrain.  I've
" driven a couple late 70s/early 80s cars/trucks with small engines
" and five speeds.  In a rural area, especially with hills, you
" never use fourth gear, and don't use it a whole lot on the
" freeway -- almost always have to gear down to maintain speed up
" grades of any inclination or length.

true, but one doesn't have to go overboard.  jeep used to have a miser
option for the comanche which included a 3.31 axle with the 2.5 in
place of the usual 3.73 or 4.11.  it depends a lot on how the four is
cammed for powerband.  this four has probably as much torque as a 199;
i don't see why it couldn't be geared similarly if cammed appropriately.

data point: mid '60s chevy nova, 2650 lbs, 153" four, hp 90@4000, 
ft-lbs 152@2400, stock axle with 3sp or pg 3.08:1.  13" wheels though.
a modern engine like the jeep would pick up a lot of 'free' torque
with computer controlled ignition timing.

" I've driven OD cars too.  I agree -- the 199 can handle pull an OD
" by 45 mph (not much before though!) with a 3.08 gear, but it
" would likely get better mileage in most areas with more gear.  I
" went from a 3.08 behind my 4.6L with AW-4 (0.70:1 OD -- same as
" the old BW units) to a 3.55 gear and gained 2 mpg on the highway.
" The engine would easily pull the OD gear, but rpm were under 2000
" around 65-70 and the engine was working harder.  Not struggling by
" any means, but obviously working harder.  I checked my mileage on
" a long trip -- from Gulfport MS to Kenosha in 2002 -- with the
" 3.08 gears and was sorely disappointed.  When I rebuilt the car
" (it was wrecked just a couple days after the trip) I wanted 3.31
" gears but ended up with 3.55 by "mistake" (bought a used set,
" seller couldn't do math or just wanted to sell!).  I was happy
" once I checked mileage on trip from Gulfport to SC and back and
" got 2 mpg more.  Not sure if 3.31 would be better or not, but
" surely couldn't be more than 1 mpg better on the highway, and I
" do like the pickup with the 3.55s!

yeah, but you're running the stock 4.0 cam right?  that has 270 deg
duration 'on the ramps', but the '60s cam has only 244.  that has to
give it the advantage in the off-idle to 2000 rpm range.
________________________________________________________________________
Andrew Hay                                  the genius nature
internet rambler                            is to see what all have seen
adh@xxxxxxxxxxxxxxxxx                       and think what none thought
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