Ego's a funny thing. There's nothing wrong with busting out the credit card and ordering up a crate motor, but most of us would never do it just because it would make us feel less manly. As a tech-heavy mag that's developed a following among hardcore DIYers, we'd expect nothing less from our discerning readers. The visceral thrill that comes from firing up a motor you built from scratch is what this hobby's all about. However, ego doesn't have to get in the way of learning. Although Smeding Performance is in the business of selling turnkey motors, you needn't compromise your manhood to appreciate expert advice.
Having built thousands of motors over the past 18 years, Ben Smeding and his crew have come across more wise guys like us than they can count. As such, Ben has a pretty thick stack of notes on how the average backyard mechanic does things versus the right way to get those same things done. Fortunately, he's willing to share that information with us. While most novices focus on things such as exotic cylinder heads and valvetrain components when building a motor, it's the little stuff like bearing clearances, ring packs, proper break-in, and optimized power curves that makes the difference between a stud and a dud. We felt so enlightened after our chat that we could feel ourselves reaching for our credit card, pride be damned.
I used to take great pride in being able to hone a block using old-style equipment. I thought I was a hot tamale, but then I got some automated machinery and realized that I wasn't.
People will always look at the price of a crate motor and its power output then proclaim they can build a similar combination for less money. According to Smeding Performance, convenience isn't the only advantage of buying a turnkey motor over assembling one in your garage. "After you build one motor, you realize your mistakes, but after you build 10, you realize what you can do better," Ben opines. "Only after you build 100 of the same motor do you finally know what you're doing. It's the little tiny things that make the difference in ultimate durability, like selecting the ideal ring package for an application. Similarly, different gaskets can distort a block differently, so with this knowledge you can compensate for that by using different torque plates."
One of the most common errors made in homebuilt motors that results in accelerated engine wear is setting bearing clearances incorrectly. Ben says just because off-the-shelf parts are sold in bundles, it doesn't mean they're compatible with one another. "Let's say you buy a rotating assembly and want to set your rod clearance at 0.0025 inch, but you have over 0.0030 inch," says Ben. "Most people would just assemble the motor as is, which would result in poor oil control and force the rings to work twice as hard to keep oil out of the cylinders. On the other hand, professional engine builders have the equipment necessary to adjust their machining to compensate for variations in clearances."We like to fit our pistons very tight, and the graphite coatings used in our motors with forged pistons helps accomplish that as well as reduce friction.