Abstract: A variety of improved compression seals for rotary engines is disclosed. The rotary engine includes a housing having walls defining a combustion chamber, a rotor within the housing and having surfaces facing the housing walls, at least one compression seal having a side exposed to high pressure gases and carried by the rotor, the seal having a seal surface sealingly engaging and slidably contacting at least one of the housing walls. The improved seal is provided with a plurality of grooves each having a substantial dimension extending nonparallel to the direction of sliding contact of the seal surface with the wall it engages, with each groove terminating short of the side of the seal exposed to high pressure gases. The grooves assist in the building of a wear preventing oil film between the seal and the housing wall without establishing a leakage path for high pressure gases.