Fastening structures with high coefficient of thermal expansion for reduction of thermally driven stresses in securing aluminum silicon alloys

An engine block crankcase utilized in a high temperature environment having thermal fluctuations comprising:

• an engine block having a plurality of holes;
• a crankcase bedplate formed from an aluminum silicon alloy and having a first plurality of holes corresponding to the plurality of holes in the engine block and a second plurality of holes;
• a crankcase cover formed from an aluminum silicon alloy and having a plurality of holes corresponding to the second plurality of holes in the crankcase bedplate, the engine block, crankcase bedplate and crankcase cover defining the crankcase;
• a crankshaft disposed in the crankcase;
• and
• a first and second plurality of threaded bolts constructed of precipitation hardenable austenitic stainless steel and having a drive nut portion and stem member portion, wherein the first and second plurality of precipitation hardenable austenitic stainless steel bolts have less than 15% thermal relaxation during thermal fluctuations;
• wherein each hole of each of the first and second plurality of holes is a threaded hole having threads, and the first plurality of threaded precipitation hardenable austenitic stainless steel bolts engage the threads of each hole of the first plurality of holes the along the stem member portion to secure the crankcase bedplate to the engine block such that the drive nut portion engages the crankcase bed plate, and the second plurality of threaded precipitation hardenable austenitic stainless steel bolts engage the threads of the each hole of the second plurality of holes along the stem member portion to secure the crankcase cover to the crankcase bedplate such that the drive nut portion engages the crankcase cover, and such that the first and second plurality of threaded precipitation hardenable austenitic stainless steel bolts retain the crankshaft therein.