MRE Books and Automotive Publications
home  |  FAQ  |  about us  |  site map
Message Boards Contact us
Search books by title or description
more search options
Performance Books and Publications  for your Ford, Lincoln & Mercury
Store Home
Sample Pages
Shop Manuals
Engine Books
Fuel & Air
Ford Books
Mercury Books
Lincoln Books
 
Store Categories
  Store Home
New Books
Best Sellers
Sample Pages
Engine Books
....Small Blocks
....Big Blocks
....4.6 & 5.4
....Power Stroke
....Rebuilding
....Engine Swap
....Other
Repair Manuals
Fuel & Air System
Paint & Auto Body
Chassis Books
Electrical Books
Ford Books
Mercury Books
Lincoln Books
Other Makes
Racing
Other Books
 
Message Boards
  Ranger & Bronco II
Ranchero & Torino
Ford, Lincoln & Merc
 
Return Policy
  Buy with confidence!
If for any reason
you're not
completely satisfied
with an item, simply
return it within 7
days and the
purchase price will
be refunded.
 
International
Orders
  We ship world wide.
All international
orders must be paid
online. Checks or
money orders drawn
on non-US banks will
not be accepted.
How to Balance an Engine
Every driver has felt the effects of an out-of-balance tire. The entire car shakes and shimmies, and
the steering wheel almost vibrates out of your hands. Now, just imagine what takes place inside an
unbalanced engine. Instead of turning at a leisurely 600 rpm like a tire, the crank may be spinning
at over 6,000 rpm. At these engine speeds, the pistons, rods, and crankshaft all become incredibly
heavy; a piston whose weight is measured in ounces can exert thousands of pounds of force when
it changes direction at TDC. A minor imbalance on a crankshaft counterweight is magnified many
times by the centrifugal force of the spinning assembly. A single ounce of metal (28 grams) has a
dynamic weight of over 700 pounds when it’s placed on a rapidly turning crankshaft counterweight.
This is why balancing is a vital part of engine blueprinting.

Balancing a tire is a breeze compared to balancing an engine. A tire rotates in one plane; an
engine has a crankshaft that is turning, pistons that are moving up and down, and connecting rods
that are doing a little of both. This helter-skelter motion produces some very strange vibrations.
The number and arrangement of the cylinders also has a tremendous impact on engine balance. A
conventional V-8 engine with cylinder banks spread 90 degrees is a beautiful solution to many
balancing problems. Yet if you lop off two cylinders to make a 90-degree V-6—as several
automakers have recently done—you have an engine that is a disaster from the standpoint of
balancing. To keep such an engine from shaking itself apart, the engineers devise all sorts of
ingenious solutions, including offset crankpins, super-soft engine mounts, and special balancing
techniques.
There are some engine designs that can never be perfectly balanced, no matter how much time,
money, and equipment you devote to the project This is why some automobile and motorcycle
manufacturers use complex counterbalancing shafts on inline fours when smoothness is an
important consideration. Rearrange those four cylinders into a “V” with the proper angle between
the cylinder banks, however, and the reciprocating assembly can be balanced much more easily.
You don’t have to understand the detailed physics behind these effects to appreciate that some
motors will always have a reputation as “shakers,” while others, with a different number or
configuration of cylinders, can be silky smooth.
Balancing an engine crankshaft
There are no low-buck alternatives
when it is time to balance an engine.
The equipment is expensive, and it
takes a skilled machinist to do the job
right.
Rotating and Reciprocating Weight
For balancing purposes, the parts of the crankshaft assembly are divided into two categories:
rotating weight and reciprocating weight. The crankshaft spins, so it is obviously part of the rotating
mass. So are the components that spin with it, like the rod bearings. The pistons, rings, and wrist
pins, on the other hand, move up and down, so they are part of the reciprocating weight. The
connecting rods are a mixed case: the small end reciprocates, while the big end rotates. When an
engine is balanced, all the components that are part of the reciprocating weight are matched so
that none of the piston/ rod assemblies is heavier than the others. In a well-balanced engine, the
weight of one piston is always offset by the weight of another piston moving in the opposite
direction.

Before balancing the rotating components, a machinist must first compute the bobweight. The
bobweight is the mass on a single rod journal. It takes into account the weight of the piston, pin,
piston locks, rings, the reciprocating and rotating parts of the rod, and the rod bearings.
When calculating the bobweight for a conventional V-8 engine, the formula used by most
machinists calls for adding 50 percent of the total reciprocating weight to the bobweight. Other
engines can require a different percentage, however. The formula used to compute the bobweight
for a 90-degree V-6 Chevrolet, for example, calls for adding only 46 percent of the reciprocating
mass.
Weights and math used to calculate the bobweight used to balance an engine
Before the crankshaft is balanced,
the bobweight must be computed.
The formula used to calculate the
bobweight varies according to the
engine design. The estimated weight
of the oil on pistons and rods, and
the percentage of overbalance (if
any), must also be included in the
calculations.
The ringer in all bobweight calculations is the weight of the oil on the components. If you dip a
piston and rod assembly into a can of oil and then weigh it, the oil will add between two and ten
grams to the total weight. How much oil actually clings to the rods and pistons inside a running
engine—and how much it affects rotating and reciprocating weight—are difficult questions.
Some engine builders feel that the oil mist in the crankcase clings together to form a rope-like cloud
that twists around the spinning crank and rotates with the assembly, which will, of course, affect the
balance. Experienced engine balancers usually include an arbitrary amount of weight in the
bobweight calculation to represent the oil film on the moving parts.
Externally balanced flywheel and harmonic balancer
When the crankshaft counterweights
are not heavy enough to balance the
engine assembly, additional weights
are added to the flywheel (or converter
flexplate) and harmonic balancer. This
flexplate and damper are from an
externally balanced 400ci Chevrolet
small-block.
High-rpm racing engines are sometimes overbalanced. When an engine is overbalanced, the
percentage of the reciprocating weight that makes up the bobweight is increased from the
customary 50 percent to about 51 percent or 52 percent. Although there may be some
theoretical advantages to overbalancing, the benefits are difficult to discern.
Advocates of overbalancing point out that bearing life is increased, while disbelievers maintain
that the practice makes no difference in either power or reliability. Overbalancing is one of those
engine-building techniques that fall into the gray category labeled “Probably Doesn’t Hurt.” For a
street performance engine, using the traditional bobweight formula will provide perfectly
satisfactory results.
Previous | Next


This has been a sample page from

Engine Blueprinting The Step-By-Step Guide to Engine Blueprinting
by Rick Voegelin
Practical Methods for Racing and Rebuilding
How to buy machine shop work
Selecting and preparing parts
This completely revised and updated version containing an
additional 32 pages is simply the best book you can buy on
engine preparation for street or racing! Rick Voegelin's highly
acclaimed combination of savvy writing and wrenching skills puts
this best-seller in a class by itself. All important preparation
techniques are clearly illustrated and explained in this easy-to-
read text. Engine Blueprinting shows the reader how to use
precision measuring tools, calculate compression ratios, degree a
camshaft, and much more! Loaded with helpful advice, this book
should be in every enthusiast's tool box.
Click below to view sample
pages from each chapter.
"Rick Voegelin's book, The Step-by-Step Guide to Engine
Blueprinting, is an excellent source of performance-oriented
engine building information for the beginner and the seasoned
veteran alike. This digest should be in every enthusiast's greasy
mitts."
-- Steve Magnante, HOT ROD
Chap. 1 - Engine Blueprinting
Chap. 2 - Cylinder Block
Chap. 3 - Crankshaft
Chap. 4 - Connecting Rods
Chap. 5 - Pistons
Chap. 6 - Cylinder Heads
Chap. 7 - Camshaft
Chap. 8 - Compression Ratio
Chap. 9 - Balancing
Chap. 10 - Assembly Tips
Softbound
8-3/8 x 10-7/8
160 pages
400 b/w photos
Item #SA21
Price: $18.95
Click here to buy now!

 
Other items you might be interested in


How to Rebuild the Small-Block Ford
In this 144 page book you're walked step by step through a rebuild,
including: Planning your Rebuild; Disassembly and Inspection;
Choosing the Right Parts; Machine Work; Assembling your Engine;
and First Firing and Break-In.  Includes 289, 302, 351W, 351C, 351M
and 400.
How to Rebuild the Small-Block Ford Price:
$18.95
Turbochargers
How to select and install the correct turbo for big or small
horsepower gains. Discusses turbocharger design, sizing,
matching, controls, carburetion, exhaust, ignition,
intercooling, marine and high altitude applications. The most
comprehensive book available. Turbo suppliers and kit
maker addresses are included. “Everything you could possibly
need to know about turbochargers for automotive applications
is in this book.  
Turbochargers Price:
$18.95

How to Build Big-Inch Ford Small Blocks
Thoroughly explains how to build a stroker, with information that will
help you to better tailor your heads, cam, intake manifold, carburetor &
exhaust system to get the most of the extra cubes. Also included is a
complete guide to head and block castings so you can choose exactly
the right parts for your project.
How to Build Big Inch Ford Small Blocks Price:
$18.95
Official Factory Guide To Building Ford Short-Track Power
How to Build Winning Short-Track Engines for Claimer Class, Spec
Series, and Sportsman Racing. Written by engineers from the Ford
Racing division, this book provides detailed instructions as well as
specific parts lists and assembly techniques for building short-track
versions of Ford's 351. Included are build lists for low dollar claimer
engines, limited late-model motors, and full competition engines.
Official Factory Guide To Building Ford Short-Track Power Price:
$18.95

Shipping is combined and discounted for multiple item purchases!
Buy more and save on shipping!
We ship Worldwide! S
ee International Shipping for more information!
Search Our Store for More Great Ford, Lincoln & Mercury Items!
FAST AND EFFICIENT SERVICE
We believe customer service and online retail can coexist. Our policy is to treat customers the way
we would like to be to treated. We strive to describe all items correctly. You have many options
online, but we believe our service is the best. We work around the clock to fill orders and ship items
within one business day. It is our goal to serve the customer before, during and after the checkout
process.
Why gamble with your money and purchase from other sellers? We look forward to doing
business with you now and in the future.
FAST SHIPPING
Items usually ship within one business day of receipt of payment! We keep large quantities on hand
and have a state of the art inventory management system to ensure your items are in stock and
ready to ship.
YES, WE HAVE A RETURN POLICY
Satisfaction is guaranteed. Our store has a NO HASSLE RETURN POLICY within 7 days of
purchase. Your exchange will be processed upon receipt. If you are not satisfied with your
purchase, our knowledgeable team will do their best to make sure you get what you are looking for.
QUALITY AND AFFORDABILITY
Why pay retail when you can save money and benefit from our purchasing power? We stock large
quantities to get you the best prices and assure the item you order will be in stock and ready to
ship. We have a COMBINED SHIPPING incentive whereby each additional item adds $
1.95 to the
s/h. The more you buy, the more you can save
!
SHIPPING
Standard shipping is a flat rate of $4.95 to anywhere in the United States with USPS Media Mail.
Priority Mail shipping is available for an additional $3.00, or $7.95 shipping. Shipping is combined
and discounted for multiple items purchases as follows: first item regular price shipping, add $
1.95
for each additional item.

INTERNATIONAL SHIPPING
We ship to Canada and Mexico with Priority Mail International for $10.95, and to most locations in
Europe, Australia, Asia, Japan and South America for $14.95. Shipping is combined and discounted
for multiple items purchases as follows: first item regular price shipping, add $
1.95 for each
additional item.
All international orders must be ordered and paid online, as we can no longer
accept checks or money orders drawn on non-US banks.
PAYMENT & SALES TAX
We accept Paypal, Visa, Mastercard, Checks and Money orders. Paypal is the preferred form of
payment. Our online shopping cart system is powered by PayPal, the most secure way to send
payment online.  Iowa residents must add 7% sales tax.
If you have any questions or comments please feel free to contact us. We look forward to serving
you and fulfilling your needs.
Thanks for your business!
MRE
PO Box 47
Grinnell, IA 50112


THE RANGER AND BRONCO II V8 CONVERSION
THE RANGER &
BRONCO II
V-8 CONVERSION

HIGH PERFORMANCE FORD ENGINE PARTS INTERCHANGE
HIGH
PERFORMANCE
FORD ENGINE
PARTS
INTERCHANGE

1969 FORD SHOP MANUAL SET
1969 FORD SHOP
MANUAL SET
ON CD-ROM

FORD PERFORMANCE
FORD
PERFORMANCE

HOW TO BUILD BIG INCH FORD SMALL BLOCKS
HOW TO BUILD
BIG-INCH FORD

SMALL BLOCKS
HOW TO BUILD MAX PERFORMANCE FORD V-8S ON A BUDGET
HOW TO BUILD MAX
PERFORMANCE
FORD V-8s ON A
BUDGET

HOW TO BUILD MAX PERFORMANCE 4.6-LITER FORD ENGINES
HOW TO BUILD MAX
PERFORMANCE
4.6-LITER
FORD ENGINES

1966 Ford Shop Manual CD
1966 FORD SHOP
MANUAL CD
HOW TO REBUILD THE SMALL BLOCK FORD
HOW TO
REBUILD THE
SMALL BLOCK
FORD

1965 Ford Shop Manual CD
1965 FORD SHOP
MANUAL CD

Store Home | FAQ | About Us | Contact us

Copyright © 1997-2008 MRE-Books. All Rights Reserved. Designated trademarks and brands are the property of their respective owners. No part of this web site may be copied or reproduced without written permission.