Everyone seems to have their own theory for engine break-in procedures these days, but sometimes sticking to the old-fashioned way of doing things is the best. "Getting a new engine is a wonderful thing, some liken it to having a new child," says Ben Smeding, owner of Smeding Performance (www.smedingperformance.com) in Rancho Cordova, California.
Smeding's specializes in building reliable, low-maintenance crate engines for truck, car, and marine applications, so the crew knows their way around most every kind of small- and big-block engine. They treat all of their engines as part of their family, which is why they put together these eight tips for when beginning kit builders are breaking in a new engine. With kits and replicars, many folks have spent a princely sum on their drivetrain, so it pays to heed the advice from a professional engine builder. Before you start your engine for the first time, keep these following things in mind:
Set Your TimingIt's important before you ever start your new engine that your initial timing is properly set. Start with rotating your crankshaft to top-dead-center for the number-1 piston on the compression stroke and install your distributor with the timing dialed-in as close as possible to the recommended specs. Install your plug wires and check the arrangement of your plug wires on the cap. Before starting the engine, double-check that you have the correct firing order of the plug wires.
Don't Forget About The CarburetionDon't harm the new engine by installing a carburetor that is too large (a common problem), too small, or too lean, which will adversely affect the air-to-fuel ratio. "Be sure to follow the size and jetting recommendations that come with your new engine," says Smeding. "Choosing the wrong carburetor is not covered by most crate-engine warranties and it would be a shame to hurt your new engine before it was ever even started."
Remember To Oil, Oil, Oil"One of the most important steps you can take in giving your engine a good start in life is pre-oiling it," says Ben. This pre-oiling step should be the last step before installing the distributor and firing the engine. Make sure not to pre-oil the engine and then start it up for the first time a month later. That initial lubrication of all the new parts and wear surfaces is critical.
Adjusting Your Valves"DON'T DO IT!" cautions Smeding. "Your valve adjustments were set correctly when your engine was assembled and no further adjustment should be necessary. The new lifters (in hydraulic-cam applications) may have a clicking sound during the initial engine running, but that noise will disappear as the lifters fill with oil.
Cool It RightMake sure you have new hoses and that they are tightly secured. A new quality thermostat should be in place and the belt driving the water pump and/or fan must be tightened to spec, but not over-tightened. Fill the cooling system with new antifreeze and water in a 50/50 mixture. If you have an electric fan, make sure it is hooked up and working before starting the engine.
Get Exhausted OutsideYour full exhaust system should be in place. The noise of open exhausts or exhausts' leaks can cover up noises from the engine that may warn of potential problems. Also, no matter the weather, the car should be started outdoors or the exhaust system ducted completely out of the garage for everyone's best interest and safety.
Be Fan-tasticSmeding Performance suggests a large box-type electric fan be placed in front of the vehicle during the initial engine break-in, even if the vehicle is being started outdoors. During break-in you need all the cooling help you can get, and if the vehicle is in a garage with the door open, the fan can help get the exhaust outside.