Jake Posted May 11, 2006 Share Posted May 11, 2006 A trader on here is selling a set of Clevite rod and main bearings and says that these will fit stock rods and mains. I asked how can they replace stock bearings that come in several different possible thicknesses. The trader in question is unwilling or unable to answer this and has advised me to post my question in the Technical section. So, can somebody explain this to me please? How can a used set of Clevite bearings be a suitable replacement for any of several different thicknesses of bearings? What am I missing here? Thank you. Quote Link to comment Share on other sites More sharing options...
Ian C Posted May 11, 2006 Share Posted May 11, 2006 A set of used bearings? Not used rods and main bearing caps? Used bearings? That aren't matched to your crank etc? I'd like to know this one as well -Ian Quote Link to comment Share on other sites More sharing options...
Bob Posted May 11, 2006 Share Posted May 11, 2006 Doesn't make sense to me, and I'm a mechanical numpty! But even on the MVP website they're only available in the two sizes - standard or +.25 Adjustable bearings? Quote Link to comment Share on other sites More sharing options...
Ian C Posted May 11, 2006 Share Posted May 11, 2006 Well, usually with a posh rebuild you get your crank ground so that each bearing journal is exactly the same, therefore you use one size bearings across all journals. You may need the oversized bearings if it's the second regrind of the crank, hence the +25thou set. Doesn't make sense with an OEM rebuild though, where you leave the crank alone and fit bearings to match the slightly mismatched journal sizes. That's my thoughts anyway. If you got your crank reground then a one-size-fits-all set of bearings would be do-able, but I doubt I'd use used ones if going to all that trouble... -Ian Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted May 11, 2006 Share Posted May 11, 2006 LOL is this a wind up? Quote Link to comment Share on other sites More sharing options...
pump gas pete Posted May 11, 2006 Share Posted May 11, 2006 Jake.... You have my complete sympathy. We have a crank that we have spent a year trying to get bearings for. I am not in the least bit mechanical but..... When I read the manual it states quite clearly that there are a number of different size cranks as standard. It states quite clearly there are a number of different size blocks as standard. It is as clear as mud to the unitiated which bearing goes on what. Clevite would appear to make the right sizes but do not describe them in Toyota terms. For our own crank we have asked dealers on this site and none are particularly helpful. In the end we have sent it to an American engine builder outside of the Supra community. If you are in any doubt .....don't Quote Link to comment Share on other sites More sharing options...
Digsy Posted May 11, 2006 Share Posted May 11, 2006 Somewhere in the workshop manual there should be a matrix of cylinder block bore versus crank journal diameter, with the correct bearing to fit for each and every combination. Most mass-production engines have graded bearing shells although its a logistical pain in the ass because it is by far the simplest and most inexpensive way of getting the proper bearing clearance for every engine build. There may well be engines out there that run large clearances and do not require graded bearings, but the 2JZ isn't one of them. Quote Link to comment Share on other sites More sharing options...
Alex Posted May 11, 2006 Share Posted May 11, 2006 How much clearance do you need for oil layer? If that's not a dumb question?? Quote Link to comment Share on other sites More sharing options...
Digsy Posted May 11, 2006 Share Posted May 11, 2006 40 microns diametral clearance is a ballpark figure. Can be higher, can be lower. Quote Link to comment Share on other sites More sharing options...
Guest Usmann A Posted May 11, 2006 Share Posted May 11, 2006 IIRC 00.20 is the stock-ish bearing clearance for the big ends. I agree with everyone here on this, blocks/cranks/rods, etc all differ, you cant just plop in any old bearings and use them. :) Quote Link to comment Share on other sites More sharing options...
i-macca Posted May 11, 2006 Share Posted May 11, 2006 And why on earth would anybody knowingly put second hand bearings in an engine build? Seems like a false economy to me.. Quote Link to comment Share on other sites More sharing options...
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