Intermediate Engine Building

With TDC verified and a lifter on the cam, another dial indicator on a magnetic base can be used to degree the cam. Checking duration at .050-inch lift as well as maximum lift is easy with this setup. Also, using the same "before and after" technique as finding TDC, we can find the actual point of highest lift, known as the lobe centerline. Adding the intake centerline (ICL) plus the exhaust centerline (ECL), then dividing by two gives the lobe separation angle (LSA).

Applying a swab of machinist's dye or layout fluid to the head and valves before lapping them in makes it easy to check out the valve job. A smooth, even witness mark around the valve and seat indicates a good valve job that should seal up immediately.

Checking spring pressure is critical on a performance engine build. A Rimac tester like this is considered the industry standard. They can be found used, but it is a good idea to spring for a new one (no pun intended) if you plan on using it for several builds. Vise-mounted spring testers work OK, but we've seen the hydraulic fluid leak out and skew the readings on some cheapo versions.

There are several varieties of ring compressors out there, including a ratcheting type that we like for small-bore engines. Snap-on makes a great universal piston ring compressor kit, but for my money a bore-specific compressor is the cat's meow. Don't tell anyone, but I've even used an oil filter wrench in a pinch ...

With the valve job checked, a height mic gives the installed height that should be used for figuring out what valvesprings to run. Shims can be placed under the springs or plus .050-inch locks can be used in the retainers to slightly modify the installed height for a desired spring.

Assuming you already have a torque wrench from your local auto parts/vanillaroma retailer, when was the last time you had it tested? Do you trust it when you just spent a few grand on the rest of your engine? Snap-on and Craftsman are both top-of-the-line, and retain their accuracy way better than the no-name torque wrenches. I have a special drawer in the toolbox just for torque wrenches so they don't mingle with the regular hoi polloi of tools.