Project Strokers Wild (Part 2): We Build 393 CID Ford 351W

Send to Kindle

After you build a serious 347 cubic inch Ford 5.0—like we did in our first installment of Project Strokers Wild—what do you do for an encore? You build it a bigger, badder brother.

In this second installment of our Stroker’s Wild engine series, we’ll show you how we built a 393 cubic inch 351 Windsor. The big advantage of a 393 is size. The engine’s extra 42 cubic inches mean power, and lots of it. Need low- and mid-range grunt for a street car or for towing? A 393 is a veritable torque monster. Horsepower? Properly built, a 393 can make an easy 450 to 500 horsepower. And it’s all in a package that will fit under the hood of a Mustang. Well, a tall hood.

A 393 can be pretty inexpensive to build, too. The only custom piece is the crank—the rest of the combination uses a .030-inch overbored stock block, stock length 351W rods, and stock-type 302 pistons. If you’re conservative with the rest of the engine, you can get those extra 42 cubes for just a few bucks more than a stock-stroke 351W buildup.

We built our 393 with a Summit Racing cast stroker crank and H-beam connecting rods, Trick Flow 10:1 forged pistons, a Crane roller cam, Trick Flow Twisted Wedge Race 225 aluminum heads, and a Holley 750 cfm double pumper carburetor on an Edelbrock Victor Jr. intake manifold. The Summit Racing crank is no longer available, but you can duplicate our build using a SCAT Series 9000 crankshaft instead. Check out the parts list below–you’ll see how easy it is to build a hot stroker Windsor of your own!

Play Prev|Next

This is the bottom end of our 393 cubic inch 351W: a brand new 3.850-inch stroke Summit Racing cast crank, stock length (5.955 inches) Summit Racing H-beam rods, Trick Flow forged pistons, Speed-Pro plasma moly piston rings, and Federal Mogul main and rod bearings.

The first step is to make sure the crank and rods cleared the cylinder sleeves on the .030-inch overbored block. As you can see they do—barely. A light touch with the die grinder and presto...plenty of clearance.

The Crane roller cam has a special "retrofit" design for use in non-roller blocks like our 1979 block. It specs out at 230-degree/238-degree duration at .050 inches and .574-inch/.595-inch lift.

To double check main bearing clearance, the crank is placed in the block, Plastigage is laid out on the main journals, and the main caps are torqued to 100 foot-pounds per factory specs.

Calculated main bearing clearance was .0023 inches. The Plastigage shows more than .002-inch clearance, so our math was right on the money.

With a rod and piston assembly in the number one cylinder, the cam is degreed using the piston stop method and a Comp Cams degree wheel. It was within one degree of what the cam card specified.

Mark uses a dial indicator to determine the maximum lift point of the camshaft lobe. Ours was 106 degrees, just one degree shy of the figure specified on the Crane cam card.

We checked piston-to-valve clearance using the clay method. Clay is placed on the number one piston, and a cylinder head and head gasket are bolted on and torqued to spec. The engine is turned over by hand and the head is then removed. Any valve indents in the clay are measured. Minimum clearance on a 351W is .060-inch intake/.080-inch exhaust. Our clay had no indents at all, meaning we had clearance galore.

With all clearances checked, Mark weight matches and balances the reciprocating assembly. A balanced bottom end reduces engine-destroying vibration, which will help the 393 run smoother and live longer.

The freshly balanced Summit Racing cast crank is put back in the block and the piston/rod assemblies are sunk in their boxes. The Speed Pro piston rings were gapped at .024-inch-.026-inch (top ring) and .020-inch-.022-inch (secondary ring).

The Summit Racing H-beam connecting rods are torqued to 70 foot-pounds. Made from aircraft quality 4340 steel, the rods come with 7/16-inch ARP 8740 rod bolts and bronze wristpin bushings for use with full floating pistons.

A Melling high volume oil pump and Moroso pickup are bolted to the bottom of the engine.

The bottom end is covered with a seven-quart Moroso oil pan. The pan is designed just for 351Ws in Fox-body cars.

The Trick Flow Twisted Wedge Race 225 Cylinder Heads feature big 206cc intake ports and 61cc combustion chambers, and come assembled with 2.08-inch/1.60-inch valves, 1.560-inch solid roller valve springs, 10-degree recessed locks, and retainers. The springs were replaced with 1.540-inch Crane dual valve springs matched to the hydraulic roller cam.

We checked valvetrain geometry to determine the correct pushrod length (important when you're running a cam larger than stock or with a smaller base circle). The 393 required 8.500-inch long pushrods.

We tightened down the 1.6 ratio Trick Flow roller rocker arms. The 7/16-inch ARP rocker arm studs are good insurance in high performance engines like our 393.

The 393 will make gobs of torque through its entire rpm range, so we didn't have to worry about hurting low-end power. That meant we could build mid and high-rpm power with a single plane manifold like Edelbrock's Victor Jr. 351W. It's designed to make power from 3,500-8,000 rpm.

The 750 cfm Holley HP Series double pumper is a good carburetor for a street/strip engine. It's small enough to run on the street without bogging the car, and its mechanical secondaries are well-suited to a relatively lightweight Mustang with a five-speed manual transmission.

The MSD Pro-Billet distributor features a fully adjustable mechanical advance and CNC-machined billet housing that is 5/8-inch smaller in diameter for extra clearance. We swapped the iron distributor gear for a bronze one that is compatible with the Crane roller cam.

Mark bolts the Meziere electric water pump to the timing cover. Note the ATI Super Damper harmonic damper right below it.

Our 393 is ready to go on the dyno and make some serious torque and horsepower.