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Discussion Starter #1
Im refreshing my engine;changing the bearings and piston rings.When i looked at the bearing sizes Toyota has 6 size bearings and Clevite has 2 sizes(standart and .25mm oversize bearings.Can anyone explain about the bearings and how to measure them order them.
Thanks,Sertan
 

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you should measure the crank and order the right dimensions

anyway if you look bearings you should buy power enterprise but clevite 77 is good of course
 

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Discussion Starter #3
The answer is invalid,i asked why Clevites has just 2 sizes!please donot answer my questions anymore.I know Supras more than you,its not enough to read Supraforums and learn something like you.
 

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I am doint the same thing right now. From what I think, Toyota bearings are pretty precise that is why they have multiple bearings sizes. IF you want to reorder the stock beaings I believe their is a # on the crank, rod or main cap, and back of bearing that you can give to Curt @Elmhurst and he can get the right ones for you. As the Clevites, I dont know. I orderd a set of STD a cupple of days ago from Titan. Hopefully by next week I will have an answer to how they fit and how they measure as my buddy at the machine shop is doing the work and walking me through the install process.

Lawrence
 

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So, I know with toyota bearings, you are basically blue-printing the engine. With aftermarket bearings, you are not.

If you don't plan on blue-printing the engine for the bearings, what would you recommend for an engine that will see 9,000 RPMS and 35psi.

I too will be replacing my bearings and want to know the best way to go.
 

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Discussion Starter #6
I am doint the same thing right now. From what I think, Toyota bearings are pretty precise that is why they have multiple bearings sizes. IF you want to reorder the stock beaings I believe their is a # on the crank, rod or main cap, and back of bearing that you can give to Curt @Elmhurst and he can get the right ones for you. As the Clevites, I dont know. I orderd a set of STD a cupple of days ago from Titan. Hopefully by next week I will have an answer to how they fit and how they measure as my buddy at the machine shop is doing the work and walking me through the install process.

Lawrence
Thanks,Sertan
 

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Anyone ever just change just the rings and rod bearings on a 2JZ w/o touching the cylinder bore, other than a light honing?

I did this to my old DSM, and it works out well if the cylinder bores are within specs.

Al
 

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i could be wrong, but i dont think a toyota bearing, rod bearing in particular, would be up to the task of handling the kind of power sertan is making
 

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Its pretty simple really...Toyota bearings are more precise and those aftermarket bearings are not. That is exactly why I went with Toyota bearings because they are a lot closer to the size I needed and everything has been just fine with my engine. You can see my engine build thread on here...it is in the Sticky section, but it is under another thread in the sticky section.

FYI...I have a 45-78 turbo (79.3mm wheel) pushing 30+lbs and everything has been fine. I have had the engine together for quite some time now.


Take Care
 

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I've also wondered about this. What exactly do you need to do to correctly fit a set of aftermarket bearings? No one has actually answered that yet.

Alex
 

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Yea, the toyota bearings have 6 different standard size and two different oversize I think. When I rebuilt my engine I used all OEM bearings and rings. Just look at the orginal bearings, they have a number on them.
 

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There must a Toyota design engineer out here that can answer this question properly, but I will provide an educated guess for those that are interested. Toyota is of course mass producing parts, and when tight tolerances are desired and you have a 'tolerance stack' of parts in an assembly it can be more cost effective to machine the parts quickly to a fairly tight tolerance, measure the finished part dimensions, and then select the interface part that best fits the assembly. The aftermarket guys are assuming that if you are going to the effort to do a full engine build that you are going to have the parts machined to tight tolerances to fit the bearing sizes they provide. Since you are not 'mass producing' your engine and the addtional expense is minimal in the grand scheme of building a single motor it ends up not being a big deal.
For example, on the 7MGTE I am building for my MKIII we are going to line bore the block and caps with the ARP's installed and size it for clevite 77's. Since the high strength fasteners change the clearances a bit this is a good idea to do anyway so it is not really adding any cost to the build. If you are doing a mild rebuild and are not using higher strength fasteners it would be better to just use proper stock toyota sizes IMHO.
Obviously I am not an expert high perfromance engine builder, so the second part of my explanation may be flawed. But I can tell you with 100% certaintly that 'selective assembly' is used by many big companies to provide high production volume tight tolerance assemblies at lower costs.
 

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Before I ordered my Clevites I read the information on their web site. They are basically set up to run a little bit larger bearing clearance than stock becuase they are expecting people to be using them in performance builds. The tighter clearances on the stock toyota bearings are good for efficiency because you get a thinner layer of oil in the bearing which is OK for normal loading. The problem is that as the loads go up you need a thicker layer of oil in the bearing to support the load. So when you go with the Clevites you might have an extra .00025 to .00075 of bearing clearance (still within spec), but if your going for 450 RWHP on a 7M I think I would rather have the extra cusion of oil and pay a little extra at the pump when I fill up. I just had my crank straightened and the journals polished and went with the std Clevites.
 

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hondas the same way, many sizes from dealer to fit any gap. Done because not all parts are built perfect as other poster stated. When I contacted the aftermarket company they told me theres was a little tight but would where right in. 90,000 miles later on my honda and its still going strong.
 

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:lol: @ this thread for the most part.

a loose motor makes power but doesnt last and a tight motor makes less power while lasting longer...i think I would rather sacrifice the small power gain but thats just me.

Here is the real reason: how many bearings does clevite expect to sell for the 2jz motor? After all, it was a fairly limited and now no longer produced motor so it is not cost effective to make a ton different sizes as Toyota does for their factory ones. Plus, people seem to believe you need these aftermarket bearings for power and will sacrifice building the motor correctlty for them.
 

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Here is the real reason: how many bearings does clevite expect to sell for the 2jz motor? After all, it was a fairly limited and now no longer produced motor so it is not cost effective to make a ton different sizes as Toyota does for their factory ones. Plus, people seem to believe you need these aftermarket bearings for power and will sacrifice building the motor correctlty for them.
is this the word of a clevite employee? didnt think so... i doubt clevites decision had anything to do with quantity, after all they would most likely make them to order anyways. i agree for the most part with aaron300... when toyota is making a motor, is way more cost effective to use different bearing sizes to adjust tolerances than it is to machine every single crank that comes through the assembly line to spec. i live in the aftermarket world and id be damned if i adjusted tolerances with bearing sizes, thats like measuring tolerances with plastigauge: people do it but its not the right way! if you are planning on building a true "built" motor and are spending high $ on nice internals, you should machine the crank to the bearings to make the exact tolerance you are trying to achieve, not get it close with a different size bearing. usually with aftermarket bearings you have a standard size and an oversize bearing in case you spun a rod and you need to turn the crank. i guess my opinion is biased because i worked in a machine shop for a year, but i was taught to do it right... the first time!
 

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I just took my crank in to a local machine shop because I spun #1 and they told me it was too far gone and it would be more cost effective to replace the crank. Is this true? I mean I have heard of all types of repairs being done to cranks, he said it like 'with the imports, its cheaper to get a new crank' but maybe he was thinking of civics or another car and didnt realize how much more expensive our parts are, even though I told him it came out of a supra and he looked up the clearances in some book he had. Is this common for the journal to be worn that badly? I'm going to mic it myself just to see, forgot my mic at work.
 

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is this the word of a clevite employee? didnt think so... i doubt clevites decision had anything to do with quantity, after all they would most likely make them to order anyways. i agree for the most part with aaron300... when toyota is making a motor, is way more cost effective to use different bearing sizes to adjust tolerances than it is to machine every single crank that comes through the assembly line to spec. i live in the aftermarket world and id be damned if i adjusted tolerances with bearing sizes, thats like measuring tolerances with plastigauge: people do it but its not the right way! if you are planning on building a true "built" motor and are spending high $ on nice internals, you should machine the crank to the bearings to make the exact tolerance you are trying to achieve, not get it close with a different size bearing. usually with aftermarket bearings you have a standard size and an oversize bearing in case you spun a rod and you need to turn the crank. i guess my opinion is biased because i worked in a machine shop for a year, but i was taught to do it right... the first time!
It is fairly obvious I am not a clevite employee and you are correct that what I said has no fact behind it. Yes there are many other explanations however the aftermarket does follow what I said in almost every way. I simply ask, why make 6 or more sizes available when you are not selling many sets to begin with. Parts are based on production numbers...thats why you can find 30 different sets of cams for a honda civic.

Meh, why argue anyways...I figure my point was just as valid but apparently not.
 

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I just took my crank in to a local machine shop because I spun #1 and they told me it was too far gone and it would be more cost effective to replace the crank. Is this true? I mean I have heard of all types of repairs being done to cranks, he said it like 'with the imports, its cheaper to get a new crank' but maybe he was thinking of civics or another car and didnt realize how much more expensive our parts are, even though I told him it came out of a supra and he looked up the clearances in some book he had. Is this common for the journal to be worn that badly? I'm going to mic it myself just to see, forgot my mic at work.
it is possible, but unlikely

i spun 3 rod bearings and my crank was still salvagable (it was still in spec after machining)

get 2 more opinions... if both disagree then go ahead with this crank... if either additional agrees then buy a new crank. You can usually find em for around 300
 
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