Chevy 350 Engine Build - Assembling A Small-Block Sleeper

This thing looks like a 350 but has a 4.00-inch crank. The extra 1/2-inch stroke is guaranteed to add some torque and horsepower.

This thing looks like a 350 but has a 4.00-inch crank. The extra 1/2-inch stroke is guaran

This is the perfect short-block for your sleeper. It looks like an ordinary Chevy 350, but underneath is a 4.00-inch stroke crank and a sturdy bottom end that is ready to handle dragstrip time, street miles, and some hits from our friend the nitrous bottle. This is intended to be an engine you can do yourself with a common block and would be perfect for a four-door Nova, C10 truck, or wrong-year Chevy wagon. It will look stock and make grunt for some serious street fun.

In this issue, we are going to show you how to assemble the short-block and get it ready for street action. Just for grins, and to get a baseline for future tinkering, we added some iron 2.02 heads and a throwaway manifold and gave it a quick pull on the dyno. We figure there is at least another 100 hp to be had with an intake, carb, and cylinder head swap. We'll show you those parts in future issues. For now, crack a cold one and discover how to massage a 4-inch crank into a 3.48-inch hole.

The problem with running a 4.00-inch stroke crank in a 350 block is the 6-inch rod required to clear the counterweights on the crankshaft. The long rod will put the piston pin up into the ring pack. It's been done before on race engines, but on the street you might end up with oil consumption and other issues. The crank on the right is from RPM and retails for about $500. It was smoothed with a Makita 4-inch disc grinder by Ted Toki at Westside Performance. He took a small amount of metal off of the end of the counterweights to get them to clear the pistons.
The problem with running a 4.00-inch stroke crank in a 350 block is the 6-inch rod require
The trick with this combo is to use 5.850-inch Chevy rods with 0.927 pin diameters that are already clearanced from Eagle. The rods work with a short, off-the-shelf piston with a pin that just clears the ring pack.
The trick with this combo is to use 5.850-inch Chevy rods with 0.927 pin diameters that ar
The 5.850 rod just clears the throw on the 4.00-inch crank. A 6-inch rod also clears but forces the piston pin high into the block. A stock 5.700-inch Chevy rod will crash the pin into the counterweight.
The 5.850 rod just clears the throw on the 4.00-inch crank. A 6-inch rod also clears but f

These forged pistons are made for a Ford 331 (302 stroker), so they are easy to get and cheap. The Ford 5.0L 1/16, 1/16, 3mm ring pack makes this whole thing work. The pistons have a part number for a 0.927 floating pin that can be used with the Eagle rods.
These forged pistons are made for a Ford 331 (302 stroker), so they are easy to get and ch
After the engine was cleaned, Toki made some preliminary cuts on the oil pan rail to clear the big end of the rods. This grinding would have been standard on 383s before the advent of the aftermarket rods with a smaller capscrew. Now it needs to be done only for a 4-inch crank.
After the engine was cleaned, Toki made some preliminary cuts on the oil pan rail to clear
Toki has what are called sacrificial bearings along with a cap that slides on and off with ease to mock up the crank and rods for clearancing. When there is a clearance issue, it is marked with a Sharpie, ground, then tried again until everything fits.
Toki has what are called sacrificial bearings along with a cap that slides on and off with

This is a close-up shot of the cap bolt clearing the pan rail. This is a trial-and-error deal, so if you have more time than money, it is a perfect summer project.
This is a close-up shot of the cap bolt clearing the pan rail. This is a trial-and-error d
Toki uses partial Hard Blok to compensate for GM core shift in case you get into the water jacket. But he says it is not necessary. He clearances many blocks, and it is a matter of safe business practice. The areas at the base of the cylinder near the pan rail (arrows) are where you might hit water.
Toki uses partial Hard Blok to compensate for GM core shift in case you get into the water
Once the rotator is completely clearanced, the engine is disassembled, bored, machined, and painted for final assembly.
Once the rotator is completely clearanced, the engine is disassembled, bored, machined, an