Tom Wilson
June 1, 2005

Horse Sense:
Powerheads takes its name from its complete line of cylinder-head work. The company offers the full spectrum of early- and late-model small-block heads, as well as the current modular fair. It's sort of neat to see old Cleveland castings mingle with the overhead-cam variety.

Here be dragons," printed 15th century cartographers when they didn't know what was on the other side of an ocean, and it might as well be the slogan of small-block Ford enthusiasts when it comes to building modular V-8s. Raised on a steady diet of pushrods, the typical V-8 fan doesn't know a thing about timing two or four camshafts, and it's only natural to be afraid of what you don't know.

And, to be honest, there are good reasons to pause. Both the GT and the Cobra modular V-8s are not free-wheeling engines. In other words, if the cams and crankshaft are not correctly timed, the pistons will foul the valves, not to mention your wallet. And, Ford didn't do anyone any favors with its corporate acid trip of mish-mashed modular parts. Learning what parts are what and getting them from a vendor on time can be a trial. And, of course, there are more parts to keep track of, and few of them are inexpensive.

But if you have a modular under your hood, there are good reasons to learn the modular ropes. Once the modular V-8 has been demystified, you'll discover that, in many ways, the modular engine is not trouble, just different.

In fact, argues Ralph Pici at modular engine specialist Powerheads Performance, assembling modular engines is easier than building pushrod small-blocks. After following Ralph through some assembly work, we see what he means. With modular engines, the brainwork is in assembling the cylinder heads, and because enthusiasts normally buy their heads assembled, either new from Ford (PIs, for example) or as assemblies from tuners such as Powerheads, there's nothing to them save for taking the heads out of their shipping boxes.

That leaves the modular short-block assembly, then setting on the heads-another easy job-and, finally, timing the cams and crankshaft while installing the timing chains and associated front-engine dress parts. So setting up the cams is the unusual part. The rest is standard stuff such as screwing on the oil pan, water pump, intake, and so on.

Main Bearing Inserts
Here's one to watch for at the parts counter. Powerheads has determined there are four modular V-8 main-bearing inserts to watch for. Starting from the left in the photo they are as follows.
1)Clevite 77 MS-2202P. The only Windsor bearing.
2) Federal-Mogul 7292 MA. This Romeo piece is called a bi-metal bearing, but it actually seems to be an all-aluminum unit. Stock replacement part.
3) Federal-Mogul 148M. The second Romeo choice for GT engines, it features tri-metal construction. The lower insert is guttered for increased oil flow.
4) Federal-Mogul 149M. The Four-Valve or Cobra bearing. The lower insert is guttered, and the locating tangs are different.

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All the inserts with open grooves are upper inserts. The plain, or less grooved inserts are lowers. The standard Ford aluminum bearings use a lower insert that is 100 percent plain. The 148M and 149M bearings use lowers that are guttered with a gradually shallower groove on each side. These are Yates-style, for more oil flow at higher rpm. Powerheads says the stock Ford aluminum bearings are best for naturally aspirated engines. They fit the crank beautifully, and often 100,000 mile crankshafts come out looking better than stock because the bearing/journal interface has polished the crank all that time. Forced-induction engines do better with the physically more robust tri-metal (steel shell) bearings. In any case, you'll throw less of a rage when the tangs and materials line up when you go to lay the crank.