How much is too much of a good thing? Ask any hot rodder or truck owner with something to tow and he'll tell you there's no substitute for cubic inches, and you can't have too much torque! The crew of motorheads at Smeding Performance (Rancho Cordova, California) keeps coming up with powerful stroker engine combinations for both Bow Tie and Blue Oval fans. Their latest is a bluer-blooded 392-cubic-inch powerplant perfect for your fat-fendered or slab-sided Ford truck.
Based on a new Ford Racing block that is basically a 351 Windsor design, the Smeding 392 combines a long arm (.350-inch) with a proven assemblage of choice aftermarket components for big-block torque and horsepower from an engine that looks similar to a stock FoMoCo 302. There are certainly other ways to get 392 cubic inches and the resultant low-end torque, but resurrecting an original Chrysler 392 Hemi engine from the '50s can be frustrating. First you have to chase down all the components; then there's the time it takes to get the rust-removal and machine work done; and in the end you've got a large hunk of cast-iron in your engine compartment (and a transmission to go with it), not to mention an equally large dent in your wallet. Instead, consider that the Smeding 392 may have an easier fitment in older trucks; every single part is brand new; one could be on its way to you in a matter of days; it's already run in and tested on the dyno; and you've got a warranty!
Why is torque so important, especially for trucks? It's all about how work is measured. Even since old James Watt in the 1600s compared the output of his steam engine to that of a draft horse, torque and horsepower have been perhaps the most-remembered terms from high school physics. To make a crude comparison, the difference between them is like an arm-wrestling competition. The power you put out to turn down your opponent's arm is the torque. How fast you do it is horsepower. In the case of internal combustion engines, torque is the twisting force applied to the crankshaft on a running engine. It's what you feel in the seat of your pants when you step on the right pedal. Horsepower is also important, but more so where time is critical, as on a dragstrip run. Peak horsepower generally occurs at a higher rpm than peak torque, and the lower the rpm for that peak torque, the more responsive your truck is going to feel. Let's face it, most of us classic truck fans aren't abusing our vehicles at the drags every weekend-we're more likely to be cruising or towing a boat or a vintage RV trailer. OK, maybe we like to beat the occasional Bimmer across the intersection, but that's the forte of torque and Smeding's 392 stroker Ford motors. A torquer like this one is especially useful in today's combo of large rear tires and overdrive automatics, which can kill highway passing power.
On the tech side, the engine build starts with brand-new Sportsman II blocks from Ford Racing. Designed for circle-track racing, these blocks are like a 351 Windsor, except that they have thicker cylinder walls and beefier webs for the main bearings. They're also roller-cam ready, but are delivered "semi-finished," so you have to bore and hone the cylinders to size and do a few other machine shop operations, then thoroughly clean the block. For most big stroker assemblies, the bottom of the cylinder bores must be ground for rod/rod bolt clearance since the crank is swinging a larger arc than a stock one. Smeding has several small-block Ford stroker packages, from the popular 347 for the 302 block to the 392 and 427 engines that start with a 351-sized block. The 392s arrive at their displacement by being bored and finished to .030-inch oversize, while the new nodular-iron stroker crank has .350-inch additional stroke than a stock 351's 3.50 inches.
The semi-finished Ford Racing Sportsman II block needs several machining steps before it c
After line-honing the mains and boring the block to .030-inch over, the last step is to ho
Machinist Dan Moody does all the balancing work at Smeding Performance. Here he's weighing