Scat Crank Prep

Scat Crankshaft

Scat Lightweight Pro Comp Crankshaft

This build uses a Scat Lightweight Pro Comp forged crankshaft with a  4.250-inch stroke (PN 4-454-4250-6385-2)  and a set of eight Scat H-Beam Pro Sport rods with a 6.535-inch  length and a ARP 2000 rod bolt upgrade (PN 445425-2).  The 4.250-inch stroke was chosen to complement the 4.600-inch cylinder bore. A larger 4.5-inch stroke could have been accommodated, but it was felt that piston speed would be too high as we wanted to run the engine as high as 7500 rpm. The crank was internally balanced at Scat (they offer this service) to accommodate our reciprocating component weights and a BHJ Billet Pro Harmonic Damper (PN CH-IBB-6-C) per Scat 's recommendation. This required the use of heavy metal slugs in the counterweights as shown. The accompanying charts below detail the balancing information for this engine.

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drilled crank journal

Drilled crank throws

Scat BBC counterweights

Counterweight trailing edge

crank throw leading edge

Counterweight leading edge

main journal oiling chamfer

Main journal oiling chamfer

Rod journal and generous fillet radius

Rod journal and generous fillet radius

Heavy metal balancing inserts

Heavy metal balancing inserts

Crankshaft Balance Specs    
    
Rotating Wt. (grams)
Big End of Rod         555
Rod Bearing              48
Oil                               2
Times                          2
Total Rotating Wt.   1210
Balance Style    Internal
    
Reciprocating Wt. (grams)    
Small End of Rod      246
Piston                        632
Wrist Pin & Buttons   235
Ring Pack    54
Total Recip Wt.       1167
    
Total Bob Wt. (grams)    2377
Heavy Metal Used    
Front 1 ea. HM 1.125 x 1.200 & 1.00 x 1.200  
Rear  2 ea.  HM 1.125 x 1.200

 

Cranshaft and Connecting Rod Specs

Scat 454 Chevy Forged Crankshaft
Pro Comp Style
PN 4-454-4250-6385-2
Stroke:                 4.250
Pin Dia.                2.200
Pin Width              2.008
Main Dia.              2.750
Weight                 61.58 lbs.

Scat 454 Chevy H-Beam Rod Set
w/ARP2000 Rod Bolts

PN 445425-2
Rod Length       6.535
Wrist Pin Dia.    .990, bushed
Journal Dia.       2.200
Big End Width    .992

 

 

 

SOURCE:

Scat Enterprises / SCAT
1400 Kingsdale Avenue,
Redondo Beach, CA 90278
1-(310) 370-5501
www.scatenterprises.com