Thread: .003" Main Clearance for Street?!

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I need some advise. I am building a 383 SBC and have been for some time now. It has been a nightmare but I am finally optimistic this attempt will work out. It has been line honed and after two polishes on the crank I am getting .003” of clearance on my mains. I am reading this is potentially too much for a street/strip motor and should shoot for around .0015”-.0025” to keep the motor running for as long as possible. I also have a Melling Select HV oil pump…will this compensate slightly for the big clearances? I am running $65 Clevite H-Series main bearings and while they offer these in .001” undersized versions I would hate to throw away $65 for the standard set. Run it as is? Get .001” bearings? Turn the crank .010 and buy matching bearings (in which cast the Scat cast crank wouldn‘t be worth it and I would want to go forged? I need some quick help as I am also possibly moving away from my car soon.


Hi all! First post and all but trying to find dedicated SBC gu-ru's.

well this happens you can go to 001 and get were you want 003 is big for a sbc street engine you can get a P bearing for 001 and that is what i would do on mild build .the race stuff i would not worry much at 003 and you can buy a set of 001 h and split the run the 001 on the main cap that with get you 002.5 but i only run the H bearing s on the street if that the only thing that fits the crank radius and when i do the bottom end i set all housing bore and the small end hi crush there is a 0005 right there that will change or bearing size you will see lower oil presure if the rods are out there as well ? but it will not blow up from it you may have low oil psi warm at idle

i have 003 on my race only motor haha. i think 3 is a bit much for the street, because of it being so big on clearance i run straight 50wt oil.