Howards Pro Max™ 2618 Forged Race Pistons
The forging design produces a stronger piston than most standard pistons for the ultimate in performance. All Howards HRC Racing Pistons are forged from 2618 billet bar stock and then heat treated and aged to a T61 condition (2618-T61). This material has less than 1% silicon particulate content. High silicon content pistons (forged from 4032 or MS75) will not stand up to the most extreme stress placed on many racing pistons. Simply stated, adding sand to the aluminum only makes it more brittle. Another advantage of 2618-T61 over the high silicon pistons is the ability to keep its shape under extreme pressure and high RPM's. "Skirt Shrinking" is not a problem with Howards HRC Racing Pistons. All HRC pistons are machined on the most modern CNC equipment in the industry. The design of the CNC turned skirts allows these pistons to work properly under intense heat and severe side loads without scuffing or splitting the cylinder walls. Dome pistons are designed with radius domes, eliminating sharp edges and "hot spots". The valve pockets are built to handle large cam profiles and oversized valves. Forced pin oilers, accumulator grooves and lock removal indents are standard. Sets include lightweight .150" wall, heat treated aircraft quality wrist pins. Double spirolox are standard.
Forged from 2618-T61 Billet Aluminum Bar Stock
Oversized Valve Pockets
Accumulator Grooves for Improved Ring Seal
Machined Oil Drain Back Holes
Lightweight Aircraft Quality Wrist Pins Included
Lock Removal Indents
CNC Turned Skirts
Radius Valve Reliefs
1/16", 1/16", 3/16" Ring Grooves
Forced Pin Oilers
Honed Pin Bores
Double Spirolox
Part Type: Pistons
Model: ProMax 2618 Forged Race Pistons
Application: Chevrolet Big Block V8 Mark IV
Piston Style: Open Chamber Dome with 2 Valve Reliefs
Cylinder Bore: 4.600"
Compression Distance: 1.245"
Crankshaft Stroke/Rod Length: 4.000" with 6.535" Connecting Rod (532ci)
Crankshaft Stroke/Rod Length: 4.500" with 6.700" Connecting Rod (598ci)
Deck Height (Zero Deck): 9.780" || 4.500" Stroke, 6.700" Stroke = 10.200" Deck
Dome Volume: 38cc
Compression Ratio: 4.000" Stroke w/ 110cc Heads: 14.0
Compression Ratio: 4.000" Stroke w/ 119cc Heads: 12.8
Compression Ratio: 4.000" Stroke w/ 124cc Heads: 12.2
Compression Ratio: 4.500" Stroke w/ 110cc Heads: 15.7
Compression Ratio: 4.500" Stroke w/ 119cc Heads: 14.2
Compression Ratio: 4.500" Stroke w/ 124cc Heads: 13.6
Piston Material: Forged 2618-T6 Aluminum
Intake Valve Relief Depth: .320"
Intake Valve Relief Diameter: 2.420"
Exhaust Valve Relief Depth: NA
Exhaust Valve Relief Diameter: NA
Accumulator Groves: Yes
Forced Pin Oilers: Yes
Gas Ports: No
Skirt Coating: CNC Turned Skirts
Lock Removal Indents: Yes
Average Piston Weight: 629
Wrist Pin Style: Press-Fit or Floating
Wrist Pins Included: .150" Heat Treated Air Craft Quality Steel
Wrist Pin Size: .990 x 2.750"
Average Wrist Pin Weight: 141
Pin Lock Included: Double Spirolox
Ring Grove Sizes: 1/16", 1/16", 3/16"
Piston Rings Included: No
Manufacturer: Howards Cams & Racing Components
Manufacturer's Part Number: 856024638
Weight: 15.0 lbs.
Warranty: Race Application, No warranty expressed or implied
Quantity: Sold as Sets of 8 |