Trust Your Builder
You put a lot of faith in your engine builder in terms of the money you spend on his product, so you might as well trust his judgement on the engine's settings. A lot of guys experiment with different things on their own and end up hurting power. Take, for example, spark-plug heat range. If an engine comes from the builder with plugs in it, I recommend using that type of plug. As an engine builder, I can get a lot closer to the ideal heat range than a driver can. It's the same with valve lash issues and other adjustable components on the engine. Before changing a lot of different things, make sure you check with the engine builder to see what he recommends. He's put in a lot of time and effort to dial in all the settings and maximize the engine, so if you go changing a lot of things just to see what will happen, you're likely to find yourself going in the wrong direction.
-Kent Davenport
Midwest Motorsports
Ames, IA

Matching Components
Racers are always looking for a better combination of components that will either give them an edge on the track or make their lives easier. Unfortunately, not every combination of parts from different sources works like you might expect. You have to be careful.

We specialize in Toyota four-cylinder engines, and last season we had a problem with a couple of customers installing Chevrolet-style hydraulic throwout bearings with the clutch. For oval track racers running the Celicas, we recommend a mechanical clutch fork. The hydraulic throwout bearing puts too much pressure on the crankshaft, which ends up blowing out the throwout bearing and seizes up the motor. You have to be careful when mixing different aftermarket components

In more general terms, one problem we've seen customers have is a failure to properly clean all the lines when installing a new engine. If you have a blown engine, it probably has sent metal throughout the oil system if it's a dry sump or remote filter. Some customers might clean out the fuel lines with carb cleaner, but they don't do anything to flush out anything else-the filters or even the oil pan. You have to be careful to thoroughly clean every system. We've started recommending Mag Filter for all our race engines. It is a magnet that mounts right on the oil filter, and it's amazing what it traps during the course of a race.

Finally, I suggest that you have your cam timing and ignition timing set up for the rpm range you expect to be running. We can have three cars with identical engines at the same track, but each driver has a different driving style, or maybe he or she has a different gear ratio. By finding out where the customer is most comfortable driving, we can tune the motor and cam for the appropriate rpm range. A lot of guys don't do that, and I don't think they understand the advantage of being able to adjust the camshaft timing, for example. I think our most frequent calls from our racers are in regards to camshaft timing, because people don't know what's possible. There is a misconception out there as to what advancing or retarding a camshaft does to an engine. Are you getting more top end or bottom end?

Again, the phone call I get is, "I've got six of my friends telling me one thing and six friends telling me something else." They want to know the truth, so they are asking questions, but they aren't always asking the right people. How do you know your friends really understand what happens if you advance the camshaft 2 degrees? I definitely recommend asking the industry leaders-don't depend on the guy in the pit stall next to you. Call the guys who built your motor or built the components that went into your motor, because they understand how it makes its power. We want to be able to support the guys who buy our engines because we want to make sure they run up front, and I'm sure other engine builders are the same way.
-Brandon Lowder
LC Engineering
Lake Havasu, AZ