Coast High Performance | (310) 784 1010 | The Home Of Pure Horsepower

  Home > Make > Chevy >

Dart Big "M" Sportsman Engine Block - Chevy 502
Dart Big "M" Sportsman Engine Block - Chevy 502

Image may be a representation of product. While we try to get as close as possible to the exact part, it is not always possible.


Call For Price and Availability!

Technical Specs

Dart engineered the Big M to be the strongest, most reliable, and easiest to build big-block on the market. With available deck heights of 9.800" and 10.200" and bore sizes of 4.250", 4.500" and 4.600", the Big M gives you the versatility to build a wide variety of engine combinations. Dart redesigned the lubrication system to create a true priority main system that oils all of the main bearings before the lifters for extra reliability. Their stepped main oil gallery (9/16˝ to 1/2˝ to 7/16˝) increases the flow of oil to the crank at high rpm, and our their oil crossover eliminates internal oil leaks around the distributor shaft. The result: more oil at the bearings and pushrods where it═s needed, and less power-robbing crankcase windage. Dart added two slotted head stud bosses on both sides of the lifter valley so you can use studs instead of hard-to-install bolts to take the place of the ˝missingţ head bolts. The Big M is fitted with billet steel 4-bolt main caps for ultimate bottom end strength. Dart machines Big M blocks in-house on precision CNC equipment to ensure quality and to eliminate the need for expensive ˝blueprinting.ţ

  • Siamesed extra-thick cylinder walls resist cracking and improve ring seal (minimum .300ţ thick with 4.625ţ bore)
  • Scalloped outer water jacket walls improve coolant flow around the cylinder barrels to equalize temperatures
  • Standard 9.800ţ and extra-tall 10.200ţ deck heights available for stroker engines
  • Four-bolt main bearing caps in steel or ductile iron have splayed outer bolts for extra strength
  • Crankshaft tunnel has clearance for a 4.500ţ stroke crank with steel rods without grinding
  • True ˝priority mainţ oil system lubricates the main bearings before the lifters
  • Oil filter pad is drilled and tapped for an external oil pump
  • Rear four-bolt cap uses standard oil pump and two-piece seal - no adapter required!
  • Lifter valley head stud bosses prevent blown head gaskets between head bolts
  • External block machining reduces weight without sacrificing strength
  • Mechanical fuel pump boss, clutch linkage mounts, and side and front motor mounts simplify installation in any chassis
  • Dual oil pan bolt patterns fit standard and notched oil pans
  • Bellhousing flange and rear main bearing are reinforced with ribs to resist cracks+H128
  • Sportsman blocks have nodular iron 4-bolt main caps. Cam bearings, freeze plugs and dowels are not included.

    For more videos, check out our Coast High Performance/Custom Performance Engines YouTube pages. Click below

    Make > Chevy
    Blocks > Aftermarket Blocks > Chevrolet - 454/502 Big Block V8