Shredder Cylinder Head - STAGE 1 - For GX200 and Clones - Predator
Shredder Cylinder Head - STAGE 1 - For GX200 and Clones - Predator
Full specs are listed at the bottom of this page.
**FITS ALL ENGINES WITH GX200 HEAD BOLT PATTERN**
Want to bolt more horsepower onto your small block clone engine? The Shredder head is a high performance sand casting with much better ports than stock style die cast clone heads. The Stage 1 Shredder head flows up to 35% more air than OEM 212/224cc cylinder heads. This head can be purchased as a bare casting or a completed head ready to bolt onto your 10mm or 11mm dowel block.
With our bare or complete Stage 1 head you'll get a ported Shredder casting that has been flowed on our bench to guarantee horsepower gains above a standard Shredder. With a complete Stage 1 Shredder you'll also get a 28.5mm stainless steel intake valve, 24mm stainless steel exhaust valve, both have 5.5mm stems, 13cc, 15.5cc, or 18cc chamber, 1.2:1 ratio heavy-duty stamped 0.095" thick steel rocker arms, billet aluminum retainers with high groove split keepers, 37lb single springs, and a billet steel guide plate. We have test fitted dual valve springs up to 60lb rates with no fitment issues in the spring pocket. This is a killer upgrade for your engine, and if paired with a 308 or larger cam and a 28mm or larger carburetor you'll see 20+hp.
If you are bolting one of these heads on any non-hemi Predator or other Rato engine you'll need our stepped head dowel pins to adapt the 11mm holes in the block to the 10mm holes in these heads.
Sold in pairs here:
Stepped Head Dowel Pin Set - 10mm to 11mm
SHREDDER CYLINDER HEAD SPECS | STOCK - STAGE 1 - 18cc, 15.5cc, or 13cc Chamber |
Stock Flow in CFM | 35% over standard D port (Approximate, depends on flowbench used, ours says 96CFM) |
Maximum Horsepower Supported Stock | 20HP+ |
Recommended Cam | 308 or 356 Depending on application |
Recommended Carburetor | Mikuni PE, PZ, or PWK 26mm or larger |
Minimum Recommended Bore | 68mm |
Chamber Volume | 18cc (10.5:1 Static Compression Ratio on a 212 Predator with piston at zero deck) 15.5cc, or 13cc |
Valve Material | Stainless Steel (both) |
Intake Runner Volume | 33cc |
Exhaust Runner Volume | 27cc |
Intake Valve Weight | 29 grams |
Intake Valve Head Diameter | 28.5mm |
Intake Valve Stem Diameter | 5.5mm |
Intake Valve Total Length | 66mm |
Exhaust Valve Weight | 22.6 grams |
Exhaust Valve Head Diameter | 24mm |
Exhaust Valve Stem Diameter | 5.5mm |
Exhaust Valve Total Length | 65.15mm |
Valve Spring Rate | 37LB/IN |
Valve Spring Retainer Material | Billet aluminum |
Valve Spring Retainer Weight | 4 grams each |
Valve Spring Keeper Style | Automotive Style Split with High Groove |
Valve Spring Keeper Material | Steel |
Valve Spring Keeper Weight | 0.65 grams each |
Dowel Pin Diameter | 10mm (We sell 10mm x 11mm stepped dowel pins) |
Head Bolt Pattern | Standard Small Block Clone |
Intake Bolt Spacing Pattern | Mikuni 48mm |
Intake Bolt Size and Thread | M6x1mm |
Exhaust Bolt Pattern Spacing | 47mm (like a HF 224) |
Exhaust Bolt Size and Thread | M8x1.25 (Standard Clone) |
Rocker Arms | 0.095" thick stamped steel 1.2:1 Ratio |
Rocker Arm Weight | 25.3 grams each |
Pushrod Guide Plate | Billet steel |
Rocker Arm Studs | Screw-In Steel M6x0.50mm/M8x1.25mm |
Weight (bare casting) | 2.342lbs |
Valve Seat Angles | Three |
Valve Seat Material | Steel |
Valve Guide Material | Steel |