Begin engine tuning with proper break-in. Regardless of what type of cam you have (roller or fl at-tappet), the rules of proper break-in apply to every type of engine because you want to seat rings and bearings with a proper run-in. When the engine fires, confirm oil pressure and take it immediately to 2,500 rpm and let it run at that speed for at least 30 minutes. The best scenario is to fire the engine on a dyno with an experienced dyno operator and run it in under a load after it has been running at 2,500 rpm for 30 minutes. For good piston ring seating, you want a load at 2,500 to 3,000 rpm. Loading with throttle builds cylinder pressure. Cylinder pressure allows rings to expand and seat into cylinder walls once the oil is at operating temperature.
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There are a number of schools of thought on automotive coolants. Water is the most effective heat-transfer liquid. However, because water causes corrosion, you must use a corrosion inhibitor. One engine builder here in Los Angeles suggests 100-percent antifreeze for zero corrosion though it is not as effective as a heattransfer medium. Evans non-aqueous coolant (no water) is the best approach because it never has to be replaced. The downside for Evans coolant is its cost at approximately $70 a gallon.
If you have dyno access, you can break-in an engine with proper tuning and operation so all you have to do is install it in the car. Dyno time begins with that good warmup at 2,500 rpm for 30 minutes to get the oil hot (minimum 140 degrees F).
The first pull you make is called a jet check. To perform a jet check, load the engine and go wide-open throttle for 15 seconds at 4,500 rpm and immediately shut down. Pull all eight spark plugs and inspect them. All the basic rules of spark plug reading apply here: tan/beige, you’re good; sooty black, rich; snow white, lean. If you see tiny dots of aluminum on the insulator, you are dangerously lean. When you are lean, go up several jet sizes bordering on rich, then come back in small steps and observe spark plug color. Spark plug insulator color is the best barometer of engine health and spirit.

Once you have burped all the air from your Cleveland’s cooling system, use a 12- to 15-pound pressure cap. The greater the pressure, the higher your coolant’s boiling point. Always have a coolant recovery system on board.

Fan selection and positioning is important. I suggest the use of a fan shroud and either a thermostatic clutch fan or lightweight fl ex fan. The fan should be positioned halfway into the shroud for optimum airflow. Also keep proper pulley ratio in mind. You don’t want a fan/water pump that turns too fast.

Engine builders all have different approaches to cooling system security. Use a heavy-duty stainless worm gear clamp on all cooling system hoses. MCE Engines suggests the use of two clamps side-by-side.

Redline Cooling manufactures the best radiators I’ve ever seen with great cooling capacity and outstanding quality. This 24-inch version for the Mustang/Cougar is fitted with SPAL electric fans, which keep your Cleveland cool in the hottest of conditions.

Regardless of what type of coolant you use, top it off with a water-retention product (such as Hy-Per Lube or Water Wetter), which reduces and eliminates surface tension. The absence of surface tension allows coolant to transfer even more heat as it flows because there’s more contact area.

K&N’s Stub Stack may look like one of those gimmicks from infomercial television. However, this easy modification is dyno proven and I’ve seen it with my own eyes. It improves both horsepower and torque by streamlining airfl ow at the air horn.

There are at least two approaches to valve adjustment. With a mechanical camshaft, valve lash is .022-inch cold for both intake and exhaust at the cam lobe’s heel (valve closed). With hydraulic lifters and a bolt-fulcrum setup, valve lash is adjusted with different pushrod lengths. If you have gone to a stud and adjustable rocker (shown), slowly tighten the adjustment until there’s no up and down play at the pushrod, then tighten 1/4 to 3/4 turn. There are variables depending upon what you want the valvetrain to do. Never go beyond 1/2 turn.

There’s a lot of debate about whether or not carburetor spacers work. They do improve torque and afford you a certain amount of horsepower. There comes a point widthwise (beyond 1 inch) where a carb spacer becomes too wide and ineffective. Around 1 inch seems optimum for most applications as long as it can clear the hood.

All fresh engines and radiators must have a cooling system fi lter to keep iron particles and other debris out of the radiator. Install one in the upper radiator hose and watch it capture debris that can clog your radiator.

Although Ford put fuel filters at the carburetor, you should place the fuel filter away from a hot engine to prevent vapor lock. For safety hard line your fuel system between pump and carburetor. If you must use hose, use high-pressure, fuel injection or braided hose. And one more thing: A 351C should never have less than 3/8-inch-diameter fuel line. When displacement goes above 400 ci with 500 hp, you need 7/16 inch. You must have the same size line from tank to carburetor.
Resist the desire to push ignition timing too far ahead. Start out in the 34- to 36-BTDC range and watch your power curve. No matter what anyone tells you, no more than 36 to 38 BTDC above 3,500 rpm. Testing under the controlled conditions of a dyno room is one thing; on the road with 92-octane fuel in a hot engine compartment under varying conditions is another thing entirely. Pin the throttle and trash your new dyno-tested engine in short order because you’re too lean or ignition timing is too far ahead. Be conservative and keep it in one piece.
Written by George Reid and Republished with Permission of CarTech Inc