nuuk 10 Posted September 13, 2023 Hey guys, I'm in the process of building my 250, just a streeter, I have everything else planned out for the engine. Just need to figure out what a good bearing clearance would to aim for. Measured the rod bearings and they came out to 0.0025 - 0.0028 inches. And the main bearings came out to 0.0027 - 0.0030 inches. Im thinking this is alright but I just want a few second opinions before I order new bearings. Also if there are any brands I should stay away from. Thanks in advance. Share this post Link to post Share on other sites
bear351c 10,270 Posted September 14, 2023 Hi mate, "general" rule is 3/4 to 1 thousandths of an inch per inch of shaft diameter. 0.0075" - 0.001" So, a 2 inch journal can have 0.002" of clearance. As I said, this is a "general rule", as things like race engines, boost, revlimit can come into play. Stick with a well known brand like ACL, Clevite, Federal Mogul etc.....they aren't that expensive considering what they do. 2 nuuk and SPArKy_Dave reacted to this Share this post Link to post Share on other sites
SPArKy_Dave 8,881 Posted September 15, 2023 18 hours ago, bear351c said: Hi mate, "general" rule is 3/4 to 1 thousandths of an inch per inch of shaft diameter. 0.0075" - 0.001" So, a 2 inch journal can have 0.002" of clearance. The crossflow in my XFN (Nissan) ute, had 6thou clearance on the mains... lol! Still ran quite reasonably, too. 1 nuuk reacted to this Share this post Link to post Share on other sites
deankxf 20,292 Posted September 16, 2023 6 hours ago, SPArKy_Dave said: The crossflow in my XFN (Nissan) ute, had 6thou clearance on the mains... lol! Still ran quite reasonably, too. crossflows will run with sand in the oil, but it's not ideal on a rebuild spec 1 1 nuuk and SPArKy_Dave reacted to this Share this post Link to post Share on other sites
