Reader: I am 17 years old and have been a subscriber to your magazine for more than a year now. I have two questions: What does it mean to have an engine balanced and blueprinted? Also, what are the advantages and disadvantages of an independent suspension versus a solid axle? If you could help me clear this up, that would be great.
Jordan Felton
Ore, NE
Editor: These questions aren't easy to answer in a few sentences, so we'll tackle the easier question first.
Depending on your suspension, a solid front axle will provide better articulation on trails than an independent setup will. They're much easier to swap in and out of a vehicle if you're looking to upgrade, and (as a rule) there are more aftermarket parts available for them. Drawbacks? They're heavier, and they don't handle as smoothly on pavement as an IFS truck. Independent rigs, by contrast, will ride and handle better on-road and usually offer less rolling resistance. On the other hand, they don't articulate very well under most trail conditions, and they're not easy at all to modify. Bottom line? If your 4x4's a trail-only rig, solid axles are the only way to go. If your truck sees pavement most of the time and only occasionally 'wheels, IFS is likely just fine for you.
Any time you write about engine tech, you could fill a shop manual with all the information you'd need, but broadly speaking, "balancing" an engine refers to the process of exactly matching the weights of all of an engine's reciprocating masses, e.g., pistons, rings, rods and rod bearings, crankshaft, and so on. A bunch of different gizmos are used to measure and compare the relative weights of all these components, and machining and/or welding is typically done afterward to subtract or add component weight wherever needed. Compression ratios and valve timing are also measured per cylinder, then readjusted as needed to "balance" or match as closely as possible. Benefits of engine balancing include improved performance and more horsepower, and most importantly, reduced friction on internal parts, which translates into smoother operation, cooler operating temps, and longer engine life. It's a fairly straightforward process, and not terribly expensive.
"Blueprinting" refers to the process of rematching (i.e., replacing) engine components with parts that are manufactured to much stronger and more precise tolerances than those found with typical stock engine internals. The goal is to reach an "ideal" balance by reducing internal weights and frictions, and improving component strength, to their maximum levels. Blueprinting typically involves a lot of precision machining and costly replacement parts, and likely isn't worth the expense to your everyday 'wheeler unless you're building a motor for racing applications. How was that for starters?
Reader: I want to first say what a great magazine you guys have! I am new to four-wheeling and just bought a '91 Isuzu Amigo 4x4 2.6L with the 31-inch factory tires. I was wondering if you could help me with a couple questions. First, I would like to do about 6-8 inches of lift, and was wondering if there is a kit out for that or any ideas? Second, can I run 37-inch tires on my Amigo if I achieve 6-8 inches of lift? Any help would be greatly appreciated, and hopefully I can get to the trails soon.
Chris Elstrom
Spencer, NC
Editor: Well, your choices are limited, but you're not out of luck. The best you can do for lifting, though, would be to combine a 3-inch suspension lift (available via Calmini) with a 3-inch Performance Accessories body lift. Even then, however, the largest tire that'll clear the 'wells without any rubbing will be 33x12.50s-unless you're prepared to start chopping off big hunks of body sheetmetal, that is. If it were us, we'd stick with the 33s, add a pair of ARB Air Lockers, a TJM winch bumper, and an 8,000-pound winch of your choice, and hit the trail with confidence.