Mike2JZ Posted October 26, 2016 Share Posted October 26, 2016 I just pulled apart a 3SGTE engine that had been "built" previously from some random garage. The incorrectly sized bottom bearings completely let go, sized the crank in the process. There is hardly anyone out there I would trust with doing the internals of my engine, hopefully you get some competent mechanics this time. Quote Link to comment Share on other sites More sharing options...
JackyBoi Posted October 26, 2016 Share Posted October 26, 2016 Aren't the Clevite77 bearings only supplied in two sizes, OEM and .25 over? I've read a lot of contradicting things about Clevite, lots of people saying they're great, but also lots of people saying they weren't. Some people have experienced the bearings being .004 out of tolerance (just one example) whilst others have ran them for thousands of miles without any issues. Then when I do the same research with ACL for example, I can't find a single bad experience Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted October 26, 2016 Share Posted October 26, 2016 I *THINK* but have never scraped one to see, that the stock Toyota 2JZ-GTE bearings are single metal clad (aluminium), not Tri-Metal (steel backing, copper plate, then babbit) and people run silly power on them with no issues, but all true "race" bearings seem to be tri metal. My gut feeling is Luiz's issue is not down to the bearing material, but something else. In theory the crank never physically touches the bearing material, but runs on a dynamically pressurised oil fil. The reason for the soft material is it will allow dirt particles to embed within it, and to allow some slight self lubrication if the oil film, hydrodynamically created by the slightly out of concentric motion of the crank journals, fails momentarily, or on dry start ups. It's a hugely complex science I do not pretend to fully understand in any real depth. Excess loading though det or sheer excessive compression forces on the power strokes, can wipe out this film, then almost instant bearing failure occurs. Modern engines run narrow, small diameter journals to minimise oil drag., and gain efficiency, and they get away with it due to the fact modern management systems keep the engines out of det, in theory... Perfect bearings and assembly, but done on an out of spec crank or in out of spec rod big end bores or main caps will just fail catastrophically when loaded significantly. Quote Link to comment Share on other sites More sharing options...
Brazil Posted October 26, 2016 Author Share Posted October 26, 2016 I *THINK* but have never scraped one to see, that the stock Toyota 2JZ-GTE bearings are single metal clad (aluminium), not Tri-Metal (steel backing, copper plate, then babbit) and people run silly power on them with no issues, but all true "race" bearings seem to be tri metal. My gut feeling is Luiz's issue is not down to the bearing material, but something else. In theory the crank never physically touches the bearing material, but runs on a dynamically pressurised oil fil. The reason for the soft material is it will allow dirt particles to embed within it, and to allow some slight self lubrication if the oil film, hydrodynamically created by the slightly out of concentric motion of the crank journals, fails momentarily, or on dry start ups. It's a hugely complex science I do not pretend to fully understand in any real depth. Excess loading though det or sheer excessive compression forces on the power strokes, can wipe out this film, then almost instant bearing failure occurs. Modern engines run narrow, small diameter journals to minimise oil drag., and gain efficiency, and they get away with it due to the fact modern management systems keep the engines out of det, in theory... Perfect bearings and assembly, but done on an out of spec crank or in out of spec rod big end bores or main caps will just fail catastrophically when loaded significantly. Chris, Where do you recommend I go from here? Should I send the parts to an independent inspector that was not involved in building the car? Where do I stand, what do you think I should be entitled too in regards to having some sort of guarantee on the work performed? Quote Link to comment Share on other sites More sharing options...
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