Part One In A Two-Part Series
One of Ford's most legendary engines is also one of its most short-lived. The 351 Cleveland small-block V-8 had a short production life-'70-'74 ('70-'73 in the Mustang) before it vanished into corporate oblivion. However, performance enthusiasts have never forgotten the 351C's broad-shouldered performance reputation, large-port cylinder heads, and throaty exhaust signature. This is why enthusiasts continue to build 351Cs for classic Mustangs.
MCE Engines in Los Angeles called us with this four-barrel 351C project and asked if we'd like to watch over their shoulders. MCE's Marvin McAfee is a born educator with a wealth of knowledge that comes from a half century of experience as an engine builder, racer, and Northrop aviation technician. He's wrenched on everything from Trans Am Boss 302s to Hemi drag racers to Pratt & Whitney jet engines.
Right off the truck from Missouri,...
Right off the truck from Missouri, Marvin gets to work on a tired 351C. He would learn that this engine has a salvageable block that would clean up at 4.030-inches, although it was the victim of poor machine work and assembly technique in the past. We're going to make it a terrific cruiser with good low- to mid-range torque.
When Craig Moore's '72 351C arrived at Marvin's shop from Mid-America Mustang in St. Charles, Missouri, it had seen better days. Marvin takes engine teardown as seriously as he does buildup. He stresses the forensics end of a teardown where you learn what an engine has been through and what needs to be done. Marvin doesn't mince words when he says, "Junk in, junk out." Just because it's new doesn't mean it is acceptable for use an in MCE engine.
Sometimes bad decisions are choosing a poor combination of parts that won't work well together. Marvin prefers to select parts or help his clients choose the right parts. All new parts are thoroughly inspected and either approved or returned when it's time to ship the engine home.
Marvin has learned through experience that an engine is the sum total of its parts, along with methodical technique. Marvin calls it attention to detail, knowing there's always a chance that a $15,000 engine could fall victim to a broken 50-cent fastener.
Our 351C had been fitted with...
Our 351C had been fitted with roller-tip 1411-1 stamped steel Comp Cams rocker arms along with a flat-tappet hydraulic camshaft. We're going to go these parts one better with Comp Cams' aggressive SK32-431-8 Magnum 284HR hydraulic roller cam with No. 1630-16 Ultra Pro Magnum 1.7:1 roller rockers, available from Summit Racing Equipment.
As Marvin understood it from the customer, he was getting a '72 351C-4V engine, but there was more to it than that. While knocking this engine down, he found a smorgasbord of Ford and aftermarket parts-a Wei-and single-plane high-rise manifold, an MSD distributor with centrifugal advance only, a Holley 4150 carburetor, Comp Cams roller tip rocker arms, a flat-tappet hydraulic street camshaft, forged pistons, and, believe it or not, '69 vintage Boss 302 head castings. It was also a four-bolt main block, which was the good news.
He also found evidence of abuse and poor tuning. He did, however, comment on how fortunate Craig Moore was. Marvin was able to save the block and keep 4.030-inch bores because they were within limits.
Next month: MCE Engines builds the 351C for street performance.
Comp Cams Camshaft/Valvetrain Information
|Camshaft Part Number||32-431-8|
|Kit Part Number||SK32-431-8|
|Camshaft Type||Hydraulic Roller|
|RPM range||2,000 to 5,500|
|Lobe Centers||110 Degrees|
|Advertised Duration||284/284 Degrees|
|Duration at 0.050-inch Lift||224/224 Degrees|
|Lifter Installation Kit||No. 31-1000|
|Pushrods||No. 7980-16 One-Piece|
|Rocker Arms||No. 1630-1 Ultra Pro Magnum|
|Valvespring Retainers||No. 741-16|
|Valvespring Locks||No. 611-16|
|Teflon Valve Seals||No. 503-16|
Although these affordable...
Although these affordable stamped steel roller-tip rockers are excellent friction reducers for a street engine, they weren't adequate enough for the cam chosen nor were they properly set up, causing abnormal wear in both rockers and studs. Some roller tips were galled from oil starvation.
A spark plug reading reveals...
A spark plug reading reveals incorrect heat range along with oil contamination and a rich mixture, which translates into a loss of performance and poor fuel economy. The rich mixture probably saved this engine from major damage because ignition timing was also too far advanced. By nature, 351C engines detonate due to poor combustion chamber design (poor quench). Timing advanced too far only aggravates the problem.
When Marvin examined ignition...
When Marvin examined ignition timing, he found it was too far ahead, potentially causing detonation and engine damage.
Marvin checks cylinder bores...
Marvin checks cylinder bores with a dial bore gauge. His customer dodged a bullet here with 4.030-inch bores less than 0.0015-inch out of round, which enabled Marvin to clean them up with a finish hone.
Ford designed the 351C to...
Ford designed the 351C to be rugged, despite some oiling system shortcomings. This is a typical nodular iron "4MA" Cleveland crankshaft with 2.749-inch main and 2.311-inch rod journals along with a D0OE-A forged 5.780-inch rod with 3/8-inch bolts.....
....We won't need these components...
....We won't need these components because we're going with an Eagle 393ci stroker kit (PN 16800030 for 4.030-inch bore), a stealthy mod that will improve street torque.