CNC High Compression Short Block, SB Chevy 421, 3.875" Eagle Crank, 6.0" Eagle Rods, 14.1:1 JE Dome Pistons

Description:


Here at CNC-Motorsports our short blocks start with new Dart little M premium cores. We start by seasoning the new Dart block, we run each block threw 7 to 10 heat cycles before we do any machine work. New blocks have a tendency to change .001 to .002 thousands after the heat cycles are complete. All blocks are checked and then line honed if needed to get a baseline for all of the BHJ blueprinting fixtures. From this point we square up the decks using BHJ’s Blok-Tru to get the desired deck heights. Once this is done we bore the block using BHJ’s Bore-Tru to get the desired spacing.

The next step is the honing process. We install main caps and torque plates to ensure cylinder bores ends up as true to actual running conditions as possible. In our honing process we aim for around 30º crosshatch to achieve the most compression while still allowing the rings to travel. Bores are measured with plates still attached and recorded on the blue print sheet.

Once all the machine work is completed, the block is washed and prepped for assembly. During the assembly process, all components are measured and corrected to obtain correct clearances. All of these measurements are recorded on the blueprint sheet.

Rotating assemblies in these short blocks are all weight matched within 2 grams, and the crankshaft is balanced with in ½ of a gram.

Here at CNC Motorsports we strive for excellence in our craftsmanship to provide our customers with the performance parts at a perfect price.

Small Block Chevy 421 Competition Short block

New Eagle 4340 Forged Steel Crankshaft, internal balance (Early Style 2 piece rear main seal "1968 - 1986")
New Eagle "ESP" 3-D H-Beam connecting rods w/ ARP L19 Rod Bolts ( Bushed Fit Pins )
New JE Extreme Duty high performance forged 2618 alloy aluminum pistons, with pins and locks
Premium Plasma moly performance piston ring set
Clevite 77 high performance rod & main bearing set
Seasoned 4 bolt main block with ARP main bolts
Dura Bond Cam Bearings
Dura Bond Finishing Kit
Pioneer Freeze Plugs
Victor Reinze Rear Main Seal
Professionally Machined, Assembled and Blue Printed in our shop


Short Block Upgrades
Total Seal Gapless Top Rings (add $ 150.00)
TriArmor Coated Bearings (add $ 108.00)
Lightweight Crankshaft (add $ 200.00)

Seller Phone Number: 800-341-1528

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Item Location: BROOKINGS, SD Get Directions

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