How to start your freshly rebuilt motor with confidence

You’re dripping sweat in your home garage after just stuffing your freshly rebuilt engine into your beloved project car or maybe use a car paint protection for it’s entire body. After days, weeks or maybe months chasing down parts, heading to all the local machine shops and checking (and rechecking) all of the tolerances and procedures, you’re ready to put your pride on the line and light the candle. Hearing your engine run is the only thing you can think about, but these first few minutes the engine is running are the most important time of its life—and your pocketbook. So, to save you some anxiety, we headed down to the legendary Lingenfelter Performance Engineering build center in Wixom, Michigan, to watch them bring a rebuilt, modern Chevrolet LT4 V8 to life and learn some of the tricks of the trade. This isn’t a comprehensive bible, but if anyone knows how to start an engine for the first time, it’s Lingenfelter.

Know what’s going into your engine

Mark Rapson, Lingenfelter’s VP of operations, says the most important thing about firing an engine is having it appropriately lubricated before you even think about hitting the starter button. “It’s like painting a car,” Rapson says. “People see a shiny color and clear coat on the outside, but it’s really the prep. It’s kind of the same thing with a motor. If the clearances aren’t set correctly or you don’t use the proper lubrication, no matter how diligent you are when you start it, you’re going to have failure.”

Choose your fluids

The engine oil and fuel debates will never end, especially as both continue to develop. Lingenfelter usually uses Royal Purple synthetic oils, except for initial engine firing—that’s when the team opts for a tried-and-true mineral oil. Engines using flat tappet camshafts probably will require more of the additive zinc dialkyldithiophosphate than engines with roller camshafts because of the high-wear nature of flat tappets.

Find your mistakes

Yes, you’ve made one, if not two. Even the folks at Lingenfelter had to chase some fuel-delivery gremlins in their state-of-the-art dynamometer cell. Check your engine for fuel, coolant and oil leaks, and make sure you’re getting power to all of the right places. For computer-controlled engines, make sure that you have the right ECU, tuned correctly for your first fire.

Prime it

Older engines that feature distributor-driven oil pumps sport a handy detail: easy priming. A tool available at nearly any auto parts store can attach to the chuck of a drill and spin the oil pump, priming it. Modern engines don’t rely on distributors, so Lingenfelter simply makes sure there is no fuel or spark and cycles the engine over with the starter to prime the oil system. With the proper assembly lube on the camshaft and other wear parts, this shouldn’t cause any excessive wear and should get oil heading into the right places.

Run it

Here’s where it gets tricky—your hard work is paying off and you’re about to fire the engine. You should triple-check your camshaft manufacturer’s instructions and any notes you wrote down for the run-in procedure. Some camshafts require specific engine speed ranges or cycles. Modern engines, with roller camshafts, aren’t quite as particular, but you need to worry about normal concerns like oil pressure and not overrevving the engine during break-in. You’ll want to run the engine for around 20 minutes, but, again, check with your build sheets.