When you fi re your Cleveland for the first time, you get a rush of excitement and anticipation because all of your hard work either proves or disproves itself with the roar of combustion. Don’t get so caught up in the experience, however, that you forget what you’re supposed to be doing.
Preparation is everything before firing your Cleveland. You want all moving parts soaking wet with lubrication, which is why you want to prime the oiling system first to get bearings and cylinder walls wet. This is performed by driving the oil pump shaft counterclockwise with a high-torque, 1/2-inch-drive drill made for endurance. During the priming process, spin the starter (spark plugs removed) to get the cylinder walls wet with oil. There is a lot of blue/white smoke when it fires; however, all is good and wet with less risk of damage to dry surfaces. Fire your engine with straight SAE 30 weight conventional engine oil and then do the first oil change at 500 to 1,000 miles including filter. Never use synthetic engine oil for break-in.
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Begin your dyno test and tune on the rich side with conservative ignition timing in the 32- to 34-degree BTDC total timing range and adjust from there. Do you have too much carburetor or not enough? Carburetor sizing depends on displacement and what you want the engine to do. A 351C needs little more than 750 cfm if you’re going aggressive. When you add displacement and power, carburetor size demand goes up.
With piston number-1 at true TDC, set and time the distributor. All Ford small-block V-8s are frustrating when it comes to getting the distributor to seat fully. As the distributor begins to seat, bump the starter and it should drop into place. Check rotor indexing.
Just because the harmonic balancer indicates TDC doesn’t mean you’ve found true TDC. Even a new balancer is suspect because the outer ring isn’t always completely accurate. I’ve seen new balancers as much as 10 degrees in error. This is why you check for true TDC going in.
Like the rest of the engine, every distributor should be blueprinted and curved prior to installation based on how the engine will be used. Retune and curve again once installed and the engine has been fi red because curving is based on what you believe the engine will do.
Tuning includes curving the distributor, which includes dialing in the rate of centrifugal advance. Autolite/Motorcraft distributors have both centrifugal (mechanical) and vacuum advance. Centrifugal advance gets tuned primarily in a distributor machine though it can be tuned during break-in. Here, “10L” indicates the advance limit. One side may be “10L” and the other “15L” for a total of 25 degrees maximum not including vacuum advance.
Ford distributors are fitted with three basic types of tunable vacuum advance units. Factory advance units (one shown here) are adjustable by adding or subtracting shims to control spring pressure. Add shims and you slow the rate of advance; subtract shims and you speed it up. Aftermarket advance units are adjusted via an Allen screw through the vacuum po Clockwise to slow advance or counterclockwise to speed it up.
Dual-point ignitions are designed to provide for a more complete coil saturation and a more potent spark at high RPM. Unless you are obsessed with originality, points of any kind make little sense. If you must go with points, you want high-quality ignition points with a phenolic rubbing block and vented contacts for cooler operation.
Detailed troubleshooting is critical, beginning with the simplest items. A misfi re, for example, begins with a thorough check of the ignition system with a multimeter.
Even a new distributor rotor isn’t always ready to install. If it doesn’t conduct electricity or intermittently conducts electricity, it is ineffective. Rotors and distributor caps must always be checked for continuity (resistance) with an ohmmeter.
There is a tremendous amount of set-up time before an engine is fired on the dyno. Jim Grubbs of JGM Performance Engineering does his homework before a dyno session: determining proper carburetor jetting, ignition timing, and header configuration. Once the engine is fired, he performs a minimum 30-minute warmup at 2,500 rpm for ring seating and work-hardening cam lobes (flattappet only). He uses a zinc-additive engine oil to get started.
Marvin explains he’s had his share of open circuit spark plugs right out of the box. He suggests the use of Autolite spark plugs. Platinum-tip spark plugs last longer, but don’t make the spark any more potent.
This 400 has been built and tuned for low- to mid-range torque with stock bore and stroke with a lot of thought put into heads, manifold, and camshaft. These are Aussie 302C heads with super-small wedge chambers for good quench on top of KB2344 forged pistons. It has been tuned for pulling power with 30 degrees BTDC total timing at 5,500 rpm. The result is 390 hp and 454 ft-lbs of torque.
Jim Grubbs of JGM Performance Engineering readies a 351C for dyno tuning with SAE 30 weight Chevron Delo 400, which is a heavy-duty lubricant designed for diesel and gasoline alike. It allows rings and bearings to seat while maintaining a good oil wedge.
Use a dual-throttle spring setup in the interest of safety. You can go side by side like this or a spring within a spring. This redundancy can save your neck if a spring fails.
Before spinning and fi ring your engine, give the oil pump a good workout, which pumps oil throughout the engine to all moving parts. You need a 1/2-inch-drive electric or pneumatic drill with reverse rotation. Run the drill for at least one minute and observe both oil fl ow and pressure.
Use an anti-collapse spring in the lower radiator hose. Though some hose manufacturers suggest the anti-collapse spring was for factory fi ll use only, this is not true. The anti-collapse spring keeps the lower hose from collapsing at high RPM.
Mix in a bottle of ASL Camguard to soften the break-in process because it does the good work of a zinc additive (only better), reducing wear and tear. At the minimum, you want a zinc additive to minimize wear, especially with a flattappet cam.
Ignition timing should be somewhere around 6 to 12 degrees BTDC at idle and total timing at 3,500 rpm at 34 to 36 degrees BTDC. This keeps things safe and minimizes the risk of detonation. You want the air/fuel mixture on the fat (rich) side to prevent detonation and a lean meltdown. You can always go leaner with time and testing. Oil pressure should be around 40 to 60 psi or 10 pounds per 1,000 rpm. At 5,000 rpm, you want a solid 50 pounds minimum.
Written by George Reid and Republished with Permission of CarTech Inc
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