Re: JPOR: cylinder taper & pulley removal

[Obi-Wan <bvh@xxxxxxxxxxxx>]

> I had always thought that the taper was calculated from subtracting the
> bottom measurement from the top measurement.  The bottom of the cylinder
> (closest to the crank) should be the bigger measurement

Other way around.  The top is bigger because the force of the explosion
pushes the rings against the wall with more force.

My question is, when people talk about the "bottom" measurement, do they
mean the bottom of the worn portion or the bottom of the entire cylinder,
which is completely unworn?  It makes a big difference in the measurements.

> The balancer...I can't seem to remember anything on it
> that would keep it from coming off once the big bolt has been removed

The big bolt & its washer only affect the balancer itself.  I need to
remove the pulley first.

> I just got my 258 back from the machine shop.  I cost $170 to bore it out 30
> over.  Looks right smart too!  A master rebuild kit will be around $475.

I'm not afraid of spending the extra cash if I need to.  I just don't
want to spend it if it isn't necessary.  I may have mis-read the PAW
catalog, but I could have sworn their master rebuild kits only came
with .030 & larger pistons, which surprised me.

> I'm thinking of upgrading the cam just a tad to get more low end but don't
> want to go too radical.  My 10 year old Clifford catalog suggests a 254 or
> 260 cam.  Is there anyway of figuring how bad my gas mileage will suffer by
> doing this?

Any idea what the factory cam was?  What year is your CJ?  I've got specs
for a '77 258, but the newer 258's would definitely have different cams.
If you get too much duration on your cam, you'll start losing gas mileage
and power at low rpm's.  More duration generally helps high-rpm power
and hurts low-rpm torque.  I've read a couple books that discuss cam
replacement, and they all warn very strongly against overcamming an
engine.  Too much duration is much worse than too little duration.

See, reading a few books can make anyone sound like they know something.

				-- Obi-Wan
				   '95.5 YJ, '77 Wag (sans engine)

-- 
Ben "Obi-Wan" Hollingsworth                             obiwan@jedi.com
         Yeah, it's about the 4x4s, but it's really the people
              that make all of this fun.  -- Cole Quinnell
            Anybody want to buy a Jeep XJ Dana 44 rear axle?