What makes a good street engine? The answer to this can vary depending on the goals of a buildup, but there are several factors that apply to a big slice of us regular-guy hot rodders. We see lots of cost-no-object buildups-you know, the thing where just the carb costs a month's pay. Building such an engine front to back costs several times more than your street project sitting in the garage. For guys with that kind of budget, there are plenty of choices, but if the spare cash is thin, all you can do is flip the page and dream. What about a big-block Chevy that uses affordable parts and hits like a wrecking ball when the throttle is stomped? That was the idea behind the Street Brawler 496.
The basis for our engine is the 454 pulled from Hunkins' Chevelle. Far from exotic, it was just a common low-compression, small-port truck motor; the kind that still shows up in junkyards and swap meets. We wanted an engine that anyone can put together in their garage, without needing a full machine shop to get it done. This is a big-block Chevy that goes together pretty much like a stock rebuild, but packing some serious punch.
The Bottom End
Although we were going to keep it cheap and real, there was no intention of doing a dingle-ball hone and re-ring overhaul on this 454. The engine showed normal wear for a twenty-plus year-old piece, and the objective was a full rebuild. When you look at the balance between cost and power potential, using a stroker combo has too much going for it to pass up. Considering the used core needs crank and rod reconditioning, boring, and new pistons just for a stock rebuild (not to mention re-balancing), a stroker kit becomes pretty attractive. For $1,249 with bearings, an Eagle stroker kit is a real bargain for the extra 42 cubic inches. When you subtract out the cost of the pistons, rings, a crank grind, rod reconditioning, bolts, balancing, and bearings for just a stock 454 build, a 496 combo is pretty hard to pass up. A stroker is the fast path to massive torque, and the economics just make sense. Add in the fact that the stroker pieces are matched, balanced, and ready to go; it sure looks attractive compared to hauling the old parts in and having to wait while they are re-worked.
Eagle has a variety of parts at different price levels, including forged cranks, H-beam rods, and forged pistons. We went with a more basic internal assembly, with a cast crank, budget I-beam rods, and hypereutectic pistons. The reasoning here was cost-to-benefit. If we were going with a high-rpm racing combo, the added insurance of high-end parts certainly adds peace of mind, but taking a realistic look at our objectives, the standard Eagle stuff is plenty stout to meet our needs. Reliability has a lot to do with rpm, and with 496 cubes working for us, there is no reason to wind the guts out of an engine this big for the street. Our plan was to let the displacement do its stuff lower in the rpm range, with a modest target of under 6,000 rpm. Shooting for a moderate rpm range dovetails with the budget approach throughout the build.
There is no need for an exotic...
There is no need for an exotic starting point if you are building a street big-block Chevy. If you have a good core to work with, like this 454 truck block pulled from Hunkins' '68 Chevelle, a stout engine can be built on a budget.
The key to a long-lasting...
The key to a long-lasting and strong-running street engine is bore prep. After boring to within .005-inch of the final bore size, Andy Mitchell of Outlaw Racing Engines hones with a No. HU123 stone to .002-inch under, and then to size with a JHU 625 stone, and completes the prep with a plateau brush. This will give an ideal surface for moly rings.
One of the nice things about...
One of the nice things about getting a complete rotating assembly like this from Eagle is that the balancing is done, saving the cost of custom balancing and making the stroker kit ready for assembly.
Since the Eagle internals provide practically everything needed to fill the block, there wasn't much to do on the machining front before the engine was ready to assemble. The stock block went to Andy Mitchell's Outlaw Racing for cleaning, inspection, and a bore and hone job, and that was it. It was pretty nice to walk out of the machine shop with only a $235 bill. Besides the bore prep, there was some clearancing of the block needed to accommodate the stroker crank's longer throw, and it was time to start putting the bottom end together using the all-new parts. The stroker kit went together about as easily as a stock rebuild, but the added cubes will pack a noticeable punch once the engine is completed.
As far as results for the...
As far as results for the dollar spent, nothing equals value like a stroker kit. This complete Eagle assembly relies on a cast crank, I-beam rods, and KB pistons. Not top-of-the-line, but in line with our budget, and plenty stout for a street-storming 496.
While a forged race crank...
While a forged race crank might be on most guys' wish list, a quality cast crank is plenty durable for a lower-cost street engine. Note the nice fillet radius on the crank journals, and the well-detailed oil passage chamfers.
With a big-inch engine turning...
With a big-inch engine turning moderate rpm, there is no reason to go wild with race parts inside. Good quality rebuild parts like Clevite P-series bearings and Perfect Circle rings will be more than up for the task, and offer a good long service life.
Similarly, KB hypereutectic...
Similarly, KB hypereutectic stroker pistons are an inexpensive way to fill the bores, and are right on target for our street-bound intention. The KB pistons offer tighter piston-to-wall clearance than a forged piston, providing quieter operation and lower oil consumption. With the KB's slight dome and our 119cc combustion chamber, we arrived at a pump-gas friendly 10.25:1 compression ratio.
Our Eagle stroker kit came...
Our Eagle stroker kit came with Eagle's I-beam capscrew rods. There are many advantages here compared to a piecemeal stroker, or rebuilding with stock rods. The fresh forgings feature ARP fasteners, bushed small-ends, and are ready to go for less than you can spend upgrading an old set of OEM rods.