Better By Design: Part 1

We've all heard of the Chevy 383 V-8 small-block, affectionately known as the "stroker." The reason we call it a stroker refers to the modification procedure that increases the "stroke" of the engine. But what you may not realize is that there never was a new, stock GM-manufactured vehicle built and sold with a 383 engine. Yet, the stroker exists and is very popular for full-sized vehicles.

The essence of this Chevy 350 V-8 engine modification is a longer piston stroke resulting from using a Chevy 400 V-8 crankshaft (with a longer rotational diameter). With the new dimensions, the 350 gains extra cubic-inch displacement (c.i.d.), plus a small gain from boring the cylinders out .030-inch over (a standard procedure whether modifying an engine or just rebuilding it to stock specs). The biggest advantage is that more displacement equals more power. Also, the longer crank throw produces more downward thrust, which translates into more torque.

We've been working with a friend who's building a lowrider with an old stroker engine in it... and a ton of miles on it. While the engine was basically sound it was definitely tired and we determined that it was in need of a complete rebuild to be reliable (read that usable). So we contacted Matt Leedy at M&R Engines in Glendale, California, to see if they could help us out.

M&R is a full-service machining facility specializing in high-performance engine design and production. They are a top-notch facility for machining, balancing, complete disassembly and assembly of engines and components. They are also warehouse distributors for nearly all brands of engine related parts and equipment, making them truly a one-stop shop.

Their research department can create computer models of engine characteristics and select the right components for virtually any application. Their engine dyno facility can perform verification tests on all engines with full test printouts. They also offer complete dyno-tested engines and engine kits for street and racing applications.

THE PLAN
After talking with Matt we decided that as long as we had to rebuild the engine we'd do it with the latest aftermarket parts to create a serious streetable 383 that is reliable and runs strong on pump gas. To make the process easier on M&R and us, we took the engine apart and delivered the short block to M&R for the final disassembly. Antonio Perez removed the pistons/rods, camshaft, timing components, crankshaft freeze plugs and oil galley plugs leaving only the bare block.

The next step was to clean the block by first baking it in their industrial cleaning oven to remove all the old oil sludge, rust and gasket materials. The process cleans cast iron material by baking it at 540-degrees (F) for approximately 50 minutes. This method is favored over hot tanking as it can clean more effectively inside the oil galleys and coolant passages that can't be seen.

The block is then placed in a shot peener to completely blast clean the burned-out residue and leave us with a clean workable cast iron block. The block is then placed in a tumbler to get our any shot trapped in the casting.

Next the block is "magna-flux" tested for cracks, a process that involves attaching an electro-magnet to the block and dusting a magnetic flux powder on the block to reveal even the slightest crack. The test showed the block was in good shape and usable.

Roger Theobald then measured the cylinder bore and found that the bore size was .040 over stock. Due to bore taper and wear, the block will have to be bored and honed to .060 over. Next, the main bearing tunnel was checked for size and the housings were found to be up to .0015 out of round. The block will be align honed to correct this.

The crankshaft is a GM 400 (as explained earlier) with the main size turned to fit the 350 block. We found the crank to be in good condition but it will have to be re-ground to use .020 undersize rods and .010 undersize mains. The existing piston and rod assemblies use 400 GM rods and stock type 350 pistons. Matt decided to discard this combination entirely.

THE DESIGN
To accomplish our goal, Matt designed a combination of components that includes Pro-Topline aluminum cylinder heads with polished stainless valves with a 2.020 intake and 1.600 exhaust, a 64cc chamber and 180cc intake runners; a hydraulic roller camshaft with 214 intake duration (at .050-inch) and 222 on the exhaust side and a 112 degree Lobe center. Intake valve lift is .488 and exhaust is .509. The hydraulic roller cam is being used for reliability, reduced wear, reduced horsepower loss and the ability to use higher valve spring pressures for upper rpm reliability.

KB forged pistons with an 18cc dish relief (which will give a 9.5:1 compression ration with the piston at 0.00 deck height) and M&R's own 4340 I-beam rods will be used. We will increase the rod length from the stock 400 rod's length of 5.565-inch to 5.700-inches for a more favorable rod angle. The 9.5:1 compression ratio will be for safe pump gas street use. And, with the .060 overbore and a 3.750-inch stroke the final displacement of our 383 actually be 388 inches. Induction will consist of an Edelbrock RPM Air Gap manifold and a Barry Grant Speed Demon 750 cfm carburetor with vacuum secondaries for smooth street use and an electric choke for hassle free operation.

All gaskets will be SCE and all fasteners will be ARP. "We use only ARP fasteners because of their manufacturing process," says Matt. "The materials that ARP uses are a superior grade to other fasteners but most importantly they 'roll' the threads into their studs and bolts after they are heat treated. Most manufacturers simply cut the threads with lathe tooling or dies which leaves weakened points that can crack and fracture," he added.

Once the engine is built we'll also be installing a sweet Vintage Air Front Runner series air conditioning system and adding polyurethane motor mounts from Energy Suspension. But we're getting ahead of ourselves. For now, follow the photos as we show you what M&R put our stroker block through to dismantle, clean, test and get it ready to rebuild, plus a look at some of the great products we'll be installing in "Better By Design--Part Two."