Page 1 of Small Block Chevrolet Motown Engine Blocks by World Products

motown small block street blocks world s motown block is without a doubt the most feature-laden engine builder friendly cast iron block on the market and because of its superior temperature control and rock-solid stability knowledgeable professionals claim it s worth up to 20 hp more than other blocks on the market at first glance one of the more noticeable differences between the world motown and oem chevrolet blocks are the bulges at each cylinder.that s because the motown has thicker cylinder walls and the water jackets have been expanded to provide required cooling the motown block can be bored to 4.200 with a .250 wall thickness remaining other physical differences between world s motown block and an oem casting include creating thicker bulkheads to provide ample support of the front and rear mains and the addition of special bosses for front-feed oil systems and rear dry sump scavenging the motown is equipped with nodular iron main caps precision registered with dowel pins and secured with beefy 1/2 bolts you should know that nodular iron caps are far superior to the oem caps as well as have advantages over aftermarket steel billet caps that s because the nodular iron will expand at the same rate as the block promoting superior main bearing life another feature is the use of standard chevrolet cam bearings throughout no need to buy several boxes of bearings as with other aftermarket blocks and pick out the same-sized ones because the block isn t step-bored solid pan rails are used to ensure proper sealing crankshafts with strokes up to 4.000 can be used without clearancing the block stocktype oil pans can be used no special wide-rail designs the mains are line-bored all head bolt holes are blind tapped and the lifter bores are indexed standard height lifters can be used most importantly the block is manufactured in its entirety to qs-9000 specifications using only two fixturing operations there s absolutely no tolerance stacking as with factory blocks that are made on an assembly line and passed from one machine to another important motown small block features made from high density cast iron 9.025 deck height with .600 minimum thickness dry sump valley scavenge lines drilled clearanced for 4.000 stroker crankshaft h-beam steel rods integral mount for spin-on oil filter dry sump systems can feed from front or rear of block available with 4-bolt nodular or splayed billet caps can be bored to 4.200 maximum water jackets expanded for better cooling standard chevy cam location and cam bearings priority main oiling system for maximum reliability solid pan rails with stock spacing oem starter fuel pump and engine mounts dual blind tapped head bolt holes for extra integrity 100 compatible with oem parts indexed lifter bores can use standard height lifters main caps are located by dowels not oem outside register technical specifications material high density cast iron deck height 9.025 standard chevrolet deck thickness .600 minimum cam bearings std chevrolet small block set main bearings std chevrolet 350 or 400 style camshaft location stock lifter bores indexed stock .843 bore bore 3.990 hone to 4.000 or 4.115 hone to 4.125 maximum bore 4.200 cylinder wall thickness 250 4.200 bore water jackets expanded for better cooling lubrication priority main oiling system oil system features integral boss for front feed boss for rear scavenge rear main cap has provisions for wet sump pump filtration integral mount for spin-on filter oil pan rails solid stock width can be clearanced for strokers crank clearance 4.000 stroke h-beam steel rods main caps nodular iron 4-bolt 1/2 w/dowels or splayed billet fuel pump oem mount starter oem mount motor mounts dual front and side cylinder head holes blind tapped to prevent leaks weight approximately 190 lbs tech note main cap attachment prior to the availability of aftermarket blocks performance enthusiasts were faced with the dilemma of scouring junkyards looking for 4-bolt main blocks or trying to fit 2-bolt blocks with aftermarket cap kits now you have a choice between standard 4-bolt main blocks with nodular iron caps and splayed billet caps rest assured that the 4-bolt setup will provide excellent reliability for most applications but for the serious performance enthusiast the splayed billet setup is preferred for several key reasons the illustration below shows a cross-section of a block casting and the relationship between bolt holes and the meat of the block as you can see the splayed bolts have a much better anchor due to available material thickness.the multi-directional clamping of the splayed bolts also helps improve bottom-end durability splayed billet main caps standard 4-bolt main caps motown cast iron blocks bare part 084010 084020 084030 084110 084120 084130 description motown cast iron bare block motown cast iron bare block motown cast iron bare block motown cast iron bare block motown cast iron bare block motown cast iron bare block deck 9.025 9.025 9.025 9.025 9.025 9.025 bore 3.990 4.115 4.115 3.990 4.115 4.115 mains 350m 350m 400m 350m 350m 400m main caps nodular iron nodular iron nodular iron splayed billet steel splayed billet steel splayed billet steel rev 2/07 8 engine blocks

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