In the Dodge Ram MPG Improvement FAQ
there is a section in the
"Engine" mods
about 'balancing the multiple cylinders of a v8 or V6
so that each cylinder is getting about the same air to fuel ratio.
This improves both MPG and Torque at the same time,
and can reduce pinging in the 'naturally worst' cylinder.

As I write this it is Thanksgiving morning
and the newspaper has a advertisement from Sears
saying the electrical Digital Multimeter with Type K thermocouple input built in,
is on sale for $19.99
it is Sears Item Number #82139

It is best to purchase 2 of these
so that you can test at least two 'sister' cylinders of the engine at a time.

Along with this multimeter
the cylinder balancing job is easier and better
if you also purchase two of the
Sears Item # 9-82367
Temperature Immersion Probes
which are Type K thermocouples with a long stainless steel 'spike'
attached to a plastic handle (wrap handle in insulation)
These also used to be $20 each a few years ago.

Dual channel EGT (exhaust gas temperature) measuring equipment typically costs in the hundreds or even thousands of $

below is a cut from the FAQ describing the cylinder balance:
====

Cylinder Balancing

Each of the cylinders in a Ram pickup engine is a little different than its
neighbor cylinders due to 'production tolerance' at the factory. In the 2003
official Ram Field Service Manual (FSM) specifications for the 5.7 Hemi
the table has a line saying the variation between cylinders can be 25%
and still be acceptable to DaimlerChrysler. Each cylinder's fuel injector
sprays slight different amounts of fuel per second, and each cylinder has
a slightly different airflow through its intake runner, cylinder head port
and valve. If you are lucky, just by chance your engine will have its
highest flowing fuel injectors installed in the cylinders that also have the
highest flowing airflow. If you are unlucky, your 'lemon' engine has the
lowest flowing fuel injectors installed in the cylinders with the highest
airflows, and vice versa.

The amount of air mixed with fuel is called the 'air to fuel ratio' (AFR) and
for decades racers and engineers have known that this AFR ratio affects
fuel economy, torque, and the temperature of the exhaust gas coming out
of the cylinder. Also for decades, people have tried to 'tune' the AFR by
measuring the temperature of the exhaust gas. The best setups for this are
expensive, but you can buy much less expensive instruments today. Sears
has multimeters like this one with a retail price of $40 but is sometimes on
sale for $20:

http://makeashorterlink.com/?G35712BFC




that has a Type K thermocouple that will measure from 0F to 1600F if you are careful not to burn the plastic handle insulation, which is only rated to 550F.

By drilling a hole
in your exhaust manifold at the 'traditional' distance of 1 inch out from the
exhaust port and inserting this thermocouple you can measure your
exhaust gas temperature (EGT) and then swap around fuel injectors to the
cylinders where the combinations yield nearly equal EGT for all cylinders.
By equalizing your EGT you can improve both torque and fuel economy - and an
added bonus is that your engine will be less likely to 'ping' on one cylinder.

How much improvement can you get? It depends on how unlucky your engine
was from the factory, but typical improvements if you can get the cylinders
nearly equal are 2-4% better fuel economy at part throttle operation during
highway cruise, and 4% better power at wide open throttle too.

Some notes on EGT testing: If you can find the Sears multimeters on sale for
$20 it might be better to buy 4 and test one side of a V8 at the same time,
then later give away the other 3 multimeters as gifts to friends and family.
With the 36 inch long leads from the thermocouple tip to multimeter you
will have limited distance so mount the meter outside your windshield,
at the rear edge of the hood, perhaps mounting 4 meters on the same board.
Choose a hole size to drill that you can later close off with a blind rivet or
tap and close with a stainless steel screw. Buy a $12 'muffler patch' kit
and use the high temperature felt gasket material to place under and over
the thermocouple wires for protection and insulation, then use a large
stainless steel hose clamp to hold the thermocouple in place during testing.
Make each test run on the same stretch of highway at about the same
air temperature with the same gasoline. Measuring EGT at the rpm of
maximum torque at full throttle is the normal spot to record the
temperatures. Testing on a steep hill where rpm changes more slowly
as the truck climbs and you can stay at legal speed is a wise idea.
Have a partner drive while you watch the meters.

You can gain additional information about the air/fuel ratios of the
various cylinders using a $60 'Colortune' sparkplug:

http://www.niksula.hut.fi/~mdobruck/siililand/mini/diy/10/dyno.htm

http://www.etoolcart.com/index.asp?P...mp;ProdID=4569

One note on the limitations of EGT testing - your engine's cylinders
also vary in their true 'dynamic' compression ratio due to sloppy
factory tolerances. Cylinders with higher compression ratios will
have LOWER EGT readings even if the AFR is the same. You can get
hints about what cylinders have higher dynamic compression ratio by
doing a compression test on all cylinders before EGT testing. The
best way of balancing AFR on cylinders is to use a 'wide range' O2
sensor in each cylinder's exhaust. This has been very expensive in
the past but the cost of wide range O2 instruments has been coming
down. See these two links:

http://carcraft.com/techarticles/116_0402_tune/

http://performancetrends.com/wide_band_uego.htm

 

While I find this interesting, and true, I believe its rather unrealistic only because you would either have to have the programming code for the Dodge ECM, or go with an aftermarket ECU--BIG BUCKS$$$$$, and of course the tuning program to start with.

Plus, wouldn't it be better to start with a blueprinted engine in the first place, just to get the value out of all the work required to achieve such fine tuning. Now, if you could possibly convince factory engine shops to do this from the get-go, then this ultra fine tune of each AFR would easily be somewhat justifiable.

Maybe if I was building a racer, which certainly wouldnot be in a truck, and perhaps a pressure aspirated configuration, I might consider spending all the resources necessary to accomplish this.

My truck seems to run fine like it is from the factory, and I'm not going to mess with something that works fine and would be used to get my racer to a track, and back, day in and day out, not to mention work every day.

Just my .02

 

I guarentee it'll take years to break even if you have to spend the $60 on that stuff. It'll probably make milage better by a percent or so which won't make a difference for a long long time. In a factory setting getting another percent is a big deal but doesn't seen feasable in this situation.

Just my opinion, and I argee, If your that wirried about it you can just get it blueprinted.

 

To have an engine carefully "blueprinted"
which means to have all its specs match the engineering blueprints
would cost about $3000 to $6,000
and afterwards the horsepower or fuel economy gains
would...common sense...be close to or slightly above
the factory engine specs.

As the above says
Dodge allows for a 'acceptable'
25% variation in compression specs
and even 'very good' V8 port fuel injected engines
vary about 8 to 12%
on cylinder to cylinder
air to fuel ratio.

If you spend about $80 for the equipment
and put in quite a bit of your own labor
you can make a measureable improvement in your
engine.

The basic idea is you take fuel injectors that naturally vary
and intake port airflows that naturally vary
and instead of trying the very difficult job of 'blueprinting' them
you just
match the high flowing fuel injectors to the high flowing ports.

To give the other side of the story
the average hourly wage in the USA
{counting fringe benefits & FICA taxes the worker does not see on the paycheck}
is about $35 per hour.

An engineer or 'master V8 engine builder's'
hourly wage equivalent is going to be over $100 per hour.
{Ray Barton of 426 Hemi fame charges more}

It is true that if you do this work yourself with your labor
and charge yourself anywhere from $35 to $100 per hour
you would never payback the investment
in your own cylinder balance job
in a reasonable time with the MPG gain,
since you probably would spend ten hours of your time doing this.

On the other hand, throttle body spacers, Tornados wirlygigs, fuel line magnets, lower temperature thermostats, and the much-discussed CAI never pay off in fuel savings for the customer,
although they are huge profit makers for the sellers.

Why do this?

To learn something about engines, hands on.

MIT, Caltech, or Duke University is now charging $43,000
for about a years worth of instruction,
which is only about 200 hours worth over that year.
That is about $215 per hour

GA Tech and RPI are bargains at much lower prices.
The new Olin College of Engineering is free..similar to Berea College.