Hello, one another question, how large can be maximum clearance between the main bearings and the crankshaft? Ask Wolfgang
A clearance of three and a half thousands of an inch would be the absolute maximum and more than desired. With this much clearance you might get a short rattle when first starting and lower running oil pressure. If a higher volume and pressure oil pump is available maybe, just MAYBE one could get by at 0.004. Each connecting rod has two bearings; the steel back/soft material one and the OIL bearing. The oil bearing must be intact because if the rod bearing metal contacts the crankshaft metal you have instant burning of the bearing and crankshaft. The oil bearing stays intact only if confined to a restricted area. If the area (clearance) is increased the oil bearing can escape and leave the metal to metal happening occur.
