Body rules will follow UMP DIRTCAR specs. Chassis and suspension will follow UMP DIRTCAR specs.
Follow UMP DIRTCAR rules unless otherwise noted.
G.M. 602 SEALED CRATE ENGINE ——————————————– 2200 pounds with driver after the race
G.M. 604 SEALED CRATE ENGINE ——————————————– 2250 pounds with driver after the race
Maximum 12” spoiler allowed. Side rudders must match template.
1. Maximum 365 C.I.
2. May run aftermarket cast-iron block. No aluminum blocks allowed.
3. Any crankshaft and rod combination. Any flat top pistons. No dome top pistons.
4. Any cast-iron heads with factory valve to piston angle. (Example 23 degree heads on GM products) (20 degree heads on Ford products , except for Ford Racing – Sportsman #M-6049-N-351) No raised runner heads. May angle mill the heads , must be with-in three degrees of factory stock. May alter the valve pockets. Heads may be ported and polished.
5. Maximum three angle valve job.Maximum valve sizes : 2.08” intake and 1.625” exhaust.
6. Any intake.
7. Any flat tappet or roller cam, no mushroom lifters. Roller rocker arms permitted. Shaft rockers allowed. Rocker studs may be pinned or screw-in type with push rod guide plates and stud girdles. May use poly locks or stock nuts.
8. Wet sump oil system must be used.
9. Any headers. Mufflers must be used.
10. Any bowl-type carburetor. Racing fuel only, no alcohol allowed.
2300 pounds with the driver after the race
Above engine with dry sump oil system.
2350 pounds with the driver after the race
May run aluminum factory angle heads, no raised runner. Bolt 50 pounds in front of the engine-plate.
2400 pounds with the driver after the race
Tire rule : Maximum 29.0 X 11.0 X 15.0
American Racer SD44, SD48, MD53, MD56
Hoosier 1300, 1350, 1450, 1600 or Spec D11, D21, D28, D45, D55
Right rear must be a SD48, 1350, D21 or harder at all times.
Tire rule will become effective April 6, 2013.