How to Break-In Your Ford 351 Cleveland Engine

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.

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.