When someone says "427" to a For enthusiast, there are mental pictures of a big-cube FE big-block with pent-roof valve covers and a pair of Holleys. With high displacement comes a lot of weight-about 650 pounds to be exact-in a lean yet stodgy FE. Just imagine if you could shoehorn 427 cubic inches beneath your hood without the weight penalty of a big-block-or the shoehorn. Now you can, because Performance Automotive Warehouse (PAW) makes it possible by taking Ford's venerable 351ci Windsor small-block and stroking it to 427 ci.
Stroking an engine to achieve greater displacement is nothing new. It's a common sense approach to getting an engine to produce more power. The engine produces more power because it ingests a greater volume of air and fuel along with the increased leverage that goes with stroke. The longer the stroke, the greater the torque, even if you aren't increasing displacement.
PAW makes it possible to get into cubic inches and greater torque with its 427 Street Beast, an affordable 400- to 450-horse stroker you can buy for less than $3,000 (long-block) or $2,500 (short-block). What makes this engine powerful yet affordable? Commonsense engine-building techniques and proven components.
PAW begins its quest for cubic inches with a 351W block bored and honed .060-inch oversize. The cylinder skirts are notched to clear the Chrysler 360ci small-block connecting rods. The 351W gets stroked a half-inch by fitting the block with a 400M crankshaft (the 400M is a tall-deck Cleveland). Keep in mind the 351W has a 3.50-inch stroke while the 400M has 4 inches of stroke. PAW takes a 400M crankshaft and removes the ridge not present in a 351W crankshaft. This gets the timing set to line up properly between the 351W block and 400M crank. The 400M crank is also machined to accept a longer Woodruff key, which keeps the harmonic balancer where it belongs. To marry the Chrysler 360 rods to the 400M crank, PAW machines the rod journals down from 2.311 inches to 2.124 inches. But there's more: PAW offset grinds the journals .125-inch to add even more stroke for a whopping 4.125 inches.
Traditional 400M engines used a 28-ounce offset-balance harmonic balancer. Because we're changing the dynamics of the engine's rotating and reciprocating weight, PAW uses the late-model 50-ounce offset balancer to counterbalance the additional reciprocating weight.
The PAW 427 Street Beast is available with a hydraulic or mechanical tappet camshaft. You can upgrade to a roller hydraulic or mechanical lifter camshaft for a few bucks more. When your PAW engine kit arrives, the cam bearings are already installed in the block. Just lube up the cam and carefully install. When you opt for a roller cam conversion, everything necessary to do the job is included with the engine kit.
This is the backbone of the...
This is the backbone of the 427 Street Beast—a modified 400M crankshaft, Chrysler 360 connecting rods, and Keith Black Signature Series hypereutectic pistons. These are actually Chevrolet 283 pistons designed for 6-inch rods. The end result is torque.
This is the PAW 427 Street...
This is the PAW 427 Street Beast block. The 351W 4-inch bores are bored and honed to 4.060 inches. Cylinder skirts are cut to clear the connecting rods (arrow). Part of the oil-pan rail (circle) must be cut to clear the crankshaft counterweight.
The modified 400M crankshaft...
The modified 400M crankshaft (right) replaces the 351W crank in the 427 engine. Rod journals are machined from 2.311 inches to 2.124 inches to work with the Chrysler 360 rods. Journals are offset ground for .125-inch more stroke. The 400M counterweights are machined down to clear the 351W block.
The 400M crankshaft snout...
The 400M crankshaft snout is machined to remove the ridge (screwdriver) which allows the timing set to line up. Additional machining allows room for a longer Woodruff key.
The 28-ounce, old-style balancer...
The 28-ounce, old-style balancer common to the 289/302/351W (left) is replaced with the 50-ounce unit (right) used on the late-model 5.0 and 5.8 V-8s.
The PAW 427 kit includes a...
The PAW 427 kit includes a high-volume oil pump for improved lubrication. Make sure the oil pump clears the crankshaft counterweight.
PAW uses the Chrysler 360...
PAW uses the Chrysler 360 connecting rod (left) for the 427 Street Beast, as compared to the 351W rod on the right. The Mopar rod employs a larger journal, which is why the 400M crank must be machined down. This rod is also longer than the 351W rod. The longer rod provides greater dwell time at the top of the bore.
Keith Black Signature Series...
Keith Black Signature Series hypereutectic pistons get the job done in the PAW 427. The rods are machined down as shown to provide rod clearance. What’s more, the Mopar rod is bushed for a free-floating piston pin design. These pistons are dished to keep compression conservative. Figure on a 10.0:1 compression ratio with 351W heads.
PAW offers the choice of a...
PAW offers the choice of a hydraulic or mechanical flat-tappet camshaft kit, including lifters. A roller camshaft kit costs more, but is worth every penny.
Factory press-fit oil galley...
Factory press-fit oil galley plugs are tossed in favor of screw-in plugs. This is a nice feature of any PAW Ford small-block.
The PAW 427 arrives on your...
The PAW 427 arrives on your doorstep with a double-roller steel timing set. You can upgrade to a gear drive for a little more money.
The PAW engine kit provides...
The PAW engine kit provides everything needed to build a handsome engine, including heads and bumpstick. Two types of 351W heads are available with the 427—open chamber for a reduced compression ratio of 9.0:1 or closed chamber for 10.0:1. Hardened exhaust valve seats are also installed.