has been found desirable to adjust the melt viscosity to betwen about 10 2 poise to about 10 5 poise so that satisfactory dispersal of the reinforcing fibers throughout the mold will take place with respect to the molecular weight of the polyimide a formulated molecular weight of from about 1 400 1 600 is desirable in order to achieve a proper melt viscosity within such range a polyimide material having a formulated molecular weight of about 1 500 referred to in the trade as a 34 pmr 15 34 is preferred in the case of the most preferred embodiment of the invention the pmr 15 will be prepared by adjusting the monomeric components of a polyimide precursor solution to include a diester of 3 3 39 4 4 39 benzophenone tetracarboxylic dianhydride 4 4 39 methylene dianiline and a monoester of 5 norbornene 2 3 dicarboxylic anhydride the monomeric components being present in a molar ratio of about 2 3 2 the molding of the sheet molding compounds of the invention is accomplished by laying up the sheets about the mold and heating them to from about 180 u00b0 400 u00b0 f during which period imidization occurs heating is continued through the resin 39 s melting point of about 520 u00b0 f to its cross linking temperature of about 550 u00b0 600 u00b0 f the volatiles generated during imidization are essentially eliminated during the imidization stage so that the subsequently formed cross linked polymer is essentially void free compression molding of the preferred polyimides of the invention is readily accomplished at from about 250 500 psi while in accordance with the.