When it comes to project cars, using a crate engine means working smarter, not harder. Rather than scrounging around a swap meet or junkyard for an old engine that might require an extensive and possibly expensive rebuild, many hot rodders and resto types now opt for pre-assembled crate engines. Ordering a mill by mail-order means you can get a dyno-tested product with a full warranty, plus a proven performance package.
What sort of engines can you have dropped off at your driveway? All sizes, types and popular brands are available from stock four-bangers to high-performance big-block V8s. Usually the latter are dyno-tested to verify output levels, which adds a few hundred dollars to the price.
Not all crate engines arrive in complete form, and ready to go. Some come as long blocks that require adding the induction system (carburetor or electronic fuel injection), along with accessories such as the starter, pulleys, water pump, distributor, plug wires and so forth.
If the manufacturer recommends a particular carburetor or distributor, it’s generally wiser to stick to that setup, since it’s usually based on dyno testing. Altering the combination may yield different horsepower and torque figures. Some companies offer crate engines with pre-matched components that eliminate the guesswork of picking the right combination of carb, intake, heads and camshaft.
Keep in mind that a pre-assembled crate engine isn’t necessarily a plug-n-play deal, and some “preflight” procedures might be required prior to firing it up. For instance, clean off any paint from engine-mount bosses and other mounting surfaces. Usually there’s no oil in the crankcase, and the customer will need to decide on which side the dipstick will be installed (the side not used will require putting in a plug to seal the hole prior to start-up).
Speaking of oil, in addition to filling the crankcase, pre-fill the filter and pressure-lube the internals prior to that first critical cranking by rotating the oil pump shaft with a drill motor (making sure it’s turning in the same direction as the engine rotation). Do not turn the engine over with the starter motor for oil priming!
Some companies also offer special break-in oils, and a zinc additive for flat-tappet cams, to ensure additional lubrication. High-performance engine builders recommend using synthetic oil, or at least a slightly thinner viscosity (5W-30) for the first 1000 miles or so.
Although normally the engine should have been dialed in at the factory before shipping, it wouldn’t hurt to check the static timing and the firing order on the plugs at the distributor cap. While you’re at it, make sure your plug wires and other heat-sensitive components aren’t too close to the exhaust headers, and that the ground wire has solid metal-to-metal contact with the frame. (This is particularly important for a street rod with a fiberglass body.) Don’t forget to add a 50/50 coolant mix to the radiator as well.
Before starting up the engine, if your vehicle is on the ground, be sure to the set the emergency brake chock the wheels, and take the transmission out of gear. Your garage area should be well ventilated, too.
That done, when you turn the ignition key for the first time, it the engine doesn’t fire up right away, don’t keep cranking it. Shut it down and check the fuel-delivery system. If the engine does kick off okay, run it to 2000 rpm right away to dissipate the oil on the camshaft.
For proper break-in, vary the revs from 1800 to 2500 rpm for the next 20 minutes, and keep checking the oil pressure and water temperature gauges (an extra pair of eyes helps here). Don’t interrupt this procedure; otherwise the cam might not break in properly.
Before the engine temperature rises, remove the radiator cap and check the coolant flow and for possible leaks. Also, make sure the electrical system is charging the battery. After the engine has been running for 30 minutes, set the ignition timing and carburetor settings, if applicable.
Once you’ve finished running the engine at no load and checked everything out, let it cool down for a few hours and re-torque the head bolts in the sequence recommended by the engine supplier.
That done, you’re now ready to fire up the engine again and head out on the road. Drive your project vehicle at varying speeds and loads on the engine for the first 30 miles, making sure not to use a lot of throttle or high revs (more than 5000 rpm). Take it easy for the 500 miles, without high revving, hard use, or extended periods of high loading. Don’t forget to change the oil and filter in the first 50 to 100 miles. After you’ve babied your crate engine during this break-in period, it’ll be good and ready to head out on highway for some harder acceleration and long-range cruising.