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22551788 - Rocket Block Chevy Small Block - 4.000"-4.180" Bore, 9.025" Deck, 2.45" Mains, 4 Bolt Main, Siamesed Bores

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This cast iron block is precision machined and does not require additional blueprinting to correct production tolerance. All block dimensions are machined to +/- .001".

The blocks extra-thick siamesed cylinder walls provide a minimum .275" wall thickness with a 4.125" bore. The cylinders can be bored to a maximum of 4.155" diameter.

This block also uses the standard GM small block V8's 4.400" cylinder bore centerlines.

The outer water jacket walls are scalloped to enhance coolant flow around the siamesed cylinders. This block is available with deck height 9.325". The reinforced deck has a minimum .625" deck thickness, regardless of the deck height specified. The head blot holes are blind-tapped and the head bolt bosses are freestanding to minimize cylinder bore distortion.

The three steel 4-bolt center main bearing caps have splayed outer bolts. The 2-bolt front and rear bearing caps are retained with studs. Blocks with standard deck heights use 2.45" main bearings; tall deck height blocks use 2.65" main bearings. This block uses a pre- 1985 two-piece small-block V8, the Rocket blocks camshaft is raised .390". This relocated camshaft will clear a 4.125" stroke crankshaft without interference, eliminating the need for a small base circle cam when using a long-stroke crankshaft. This block uses big-block V8 cam bearings. These larger cam journals allow the camshaft base circle diameter to be enlarged which enhances camshaft strength and reliability.This block uses custom rocket block specific camshafts available through Crane and other quality camshaft manufacturers. it also uses a special longer rocket block specific timing chain set, available from Cloyes.

The lubrication system has been revised. This block has a priority main lubricating system that directs oil to the main bearings before the cam bearings. The main oil gallery is located next to the camshaft tunnel: oil can be pumped into this gallery through a boss above the timing chain cover or through the bell housing flange behind the #7 cylinder. In wet sump versions the rear main bearing cap is machined for a standard oil pump. The oil pan rails are spread .800" compared to a production small-block V8. These pan rails will clear up to a 4.125" stroke camshaft in tall deck blocks with minor modifications.Special Rocket block specific oil pan is needed. Available from Moroso and other quality oil pan suppliers.

Other additions to this block are dual starter mounts, production bosses for side and front engine mounts, and provisions for a block-mounted mechanical fuel pump. Depending on components used, bottom of bores and oil pan rails may require notching and additional machine work for connecting rod and counterweight clearance. Mounting the starter on the left side of the block provides additional clearance for an extended oil pan. If the block-mounted oil filter is eliminated, a remote filter is required.

This bare block weighs 202 Lbs. A 4.155" bore and a 4.125" stroke will yield a 447 c.i. engine.

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Shipping Information

  • Item Requires Shipping
  • 225.0 lbs.
  • W19.0000” x H16.9000” x L28.3000”
  • FREE 48 State Shipping

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