Chevy 350 Engine Value Pack - Bullet Short-Block--On The Cheap!

Pro-Motion Racing Engines... 

   

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Pro-Motion Racing Engines in East Hanover, New Jersey, took care of all the machine work that needed to be done. First and foremost, the block was placed in a high temperature wash that dispels all the dirt and paint for a clean surface to work with. Next, the cylinder head deck was cut to create a smooth, level, surface for the engine block and cylinder head to meet. Also, engine builders use this as one of the tools to finely adjust the compression ratio of the engine. It was necessary to provide the crankshaft, piston, and rod specifications to Larry from Pro-Motion so he could cut the necessary amount to maintain our 9.6:1 compression ratio. After assembly, the piston was 0.008-inch in the hole, almost exactly where we wanted it.

In our November 2008 issue, we slapped a Trick Flow Specialties top-end kit on our high-mileage passenger car 350 ci short-block and forced out 428 hp and 421 lb-ft of torque. No doubt, our stressed short-block was kicking and screaming all the way through the rpm range, but performed like a champ nonetheless. At 8.0:1 compression, and on 87-octane, our passenger car powerplant could have lived for another 50,000 miles ... maybe.

We weren't ready to take that chance, as the smogger 350 from 1973 was showing its age. The rings had jagged edges, the rods and crankshaft were practically touching, and 20 pounds of sludge had accrued just about everywhere. Thankfully, Summit Racing Products provided a cheap and efficient resolution with its 350 Rotating Assembly Value Pack spec-ed out at 9.6:1 compression. The kit comes with a cast steel crankshaft, forged I-beam connecting rods, and hypereutectic 0.030-over pistons, balanced and ready for assembly.

Also included in the kit are wrist pins, piston rings, rod and crank bearings, gaskets, oil pump, timing chain, and essentially everything you need to complete assembly in your stock block.

We took the standard bore 350 block down to Pro-Motion Racing Engines (East Hanover, New Jersey) for some essential machine work. We gave it a steam bath, decked the block, bored it out to 0.030-over, and gave it a final finishing hone. Then, the assembly began at Steve Ficacci Racing Engines where we washed and cleaned all the parts, cut the piston rings, and put the puzzle together piece by piece. Once completed, we went over to B&B Automotive in Lynbrook, New York, (not to be confused with B&B in Rahway, New Jersey, where the November tests were completed) and got to makin' horsepower.

We had the 355 on the hydraulic roller-cammed engine dynamometer early in the morning and began the 20-minute break-in. After some tuning and tweaking with both the shop carburetor and out-of-the-box 750cfm Summit Racing carb, we made 468 hp and 443 lb-ft of torque. This was thanks to 37-degrees of timing, 93-octane fuel (at $1.96 a gallon mind you) and 150-degrees of oil temperature. We have some plans for our now brand-spankin'-new small-block, including some time at the track, but not before we throw a rubber-band-style beatin' on it next month. Make sure to check next issue for a supercharged follow-up that is not to be missed.

The next stop for the motor...        read full caption The next stop for the motor was over to the engine bore, where we cut approximately 0.030-inch out of the cylinder bores to match the 0.030-over pistons. While measuring our block prior, we noticed the cylinder bores were out of round. Once complete, we were within just a thousandth or two of perfectly round and had zero taper from top to bottom.

Honing an engine block is...        read full caption Honing an engine block is a critical part of the process. The key to optimal ring support and oil retention is a proper honing job on the cylinder walls. This all comes down to the depth and angle of the crosshatch used. It is necessary to create a crosshatch that allows for some oil to be held as the piston rings slide past, but not too much to damage them. For this reason, make sure to visit a reputable machine shop for this process, and ultimately, all of the machining.

The D-cup pistons that come...        read full caption The D-cup pistons that come with the kit are hypereutectic aluminums with 22cc of head volume. As mentioned before, the crankshaft, rods, and pistons are all balanced from Summit Racing. Hypereutectic simply means that two alloys are chemically combined. By adding silicon to the piston's alloy, the piston expansion is dramatically reduced.