OEM bottom end bearings

CyFi6

CyFi6

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I have an 89T engine that i bought and i have yet to open up the bottom end before putting it into my supra. Ive been reading through the TSRM about the bearings and i understand there are 5 different possible bearings sizes for the stock bottom end. What i was wondering is, assuming the engine i have has the stock bottom end and all i want to do is put new bearings, is it suggested that i buy brand new OEM bearings with the specific correct number bearing (about $40 a pop) or is it acceptable to use aftermarket "std" size bearings in it as long as oil clearance still is "in spec" once i put the new aftermarket bearings in? Are there cases where using aftermarket "std" size bearings will bring the oil clearances out of specifications? Thanks for the help.

While i have the pan off i plan to shim the pump 5mm, shim the stock filter head about 2mm, and I am also going to replace the oil squirter bolts. Are there any other things recommended that i do while i have the pan off? Thanks for all the help, it is much appreciated.
 
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speedfreak426

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Mar 31, 2008
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CyFi6;1228613 said:
I have an 89T engine that i bought and i have yet to open up the bottom end before putting it into my supra. Ive been reading through the TSRM about the bearings and i understand there are 5 different possible bearings sizes for the stock bottom end. What i was wondering is, assuming the engine i have has the stock bottom end and all i want to do is put new bearings, is it suggested that i buy brand new OEM bearings with the specific correct number bearing (about $40 a pop) or is it acceptable to use aftermarket "std" size bearings in it as long as oil clearance still is "in spec" once i put the new aftermarket bearings in? Are there cases where using aftermarket "std" size bearings will bring the oil clearances out of specifications? Thanks for the help.

While i have the pan off i plan to shim the pump 5mm, shim the stock filter head about 2mm, and I am also going to replace the oil squirter bolts. Are there any other things recommended that i do while i have the pan off? Thanks for all the help, it is much appreciated.
Click to expand...

BUMP
I have the same question
 
gaboonviper85

gaboonviper85

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Jan 13, 2008
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Toyota uses "select fit" bearings which means that obviously damn near everything is a bastard size...if useing an aftermarket bearing such as clev-77's then you generally need to polish the crank so all the pins and journals are the correct size, then alignhone the block back to spec, and recondition the rods so the are all the same...you are stuck buying the bearings from toyota if you want to avoid the machine work.
 
pbasil1

pbasil1

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Jan 30, 2008
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If your replacing the bearings, you will need to resurface the crank shaft as well. And thats a lot of work just for some bearings, so i would just plan a whole bottom end rebuild for the better.
 
CyFi6

CyFi6

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gaboonviper85;1249596 said:
Toyota uses "select fit" bearings which means that obviously damn near everything is a bastard size...if useing an aftermarket bearing such as clev-77's then you generally need to polish the crank so all the pins and journals are the correct size, then alignhone the block back to spec, and recondition the rods so the are all the same...you are stuck buying the bearings from toyota if you want to avoid the machine work.
Click to expand...

How would a polish bring all the journals to the same size? Do they measure it as they polish? Also, if you line hone the block done you need oversize bearings then because of the increased size of the block saddles?
 
gaboonviper85

gaboonviper85

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They can shave the caps and bring the bore back to standard spec. Same with rods....

Generally the crank pins and journals only vary a few .0001's and so they will polish the bigger ones a bit more as polishing does remove metal.

And no it isn't alot of work to resurface a crank....takes about 15 min ifbthe crank wasn't rk'd
 
CyFi6

CyFi6

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Makes sense. So just to make sure, in order to fit aftermarket "std" size bearings, the journals need to be polished all to the same diameter (which the machine shop would know?), the rods need to be re sized to a size the machine shop would know, and the block needs the saddles re sized to a spec that the machine shop knows? If i were to take my block and crank etc to the machine shop and tell them that all my journals, rods and main tunnel are factory oem specs, and that i want to fit "Standard size" aftermarket bearings, they would know exactly what to do?
 
CyFi6

CyFi6

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I understand that much, but why do they even sell std size bearings if they are so much work to get to fit?
(Not to mention how hard it is to figure out the toyota numbering/where to find it! Supposedly different years have different marks in different places?

Is the aftermarket "std" size bearing equal in size to any of the available 5 toyota bearings?
 
CyFi6

CyFi6

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Well, I don't completely understand it, and I don't feel like that means I'm not qualified to touch the engine...that is kind of lame. I understand the numbering system, but I have not found any solid answers on where to find the numbers. I do not have to worry about this, because my engine is going to need everything reworked, but I am asking all this because I want to learn about it all.

Like I was asking earlier, what is the reason that aftermarket companies even make standard size bearings if they cannot be used without major machine work?
 
2

2jz88mk3

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Dec 31, 2008
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CyFi6;1257485 said:
Like I was asking earlier, what is the reason that aftermarket companies even make standard size bearings if they cannot be used without major machine work?
Click to expand...

Capatalisms' greatest invention: choice
 
I

IJ.

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Because they're used with machine work.....

In the factory tooling wears and there are slight variations during a run so they use a set of Go/No Go gauges to measure each hole and stamp the block so when the block gets to the bearing station all the assembler need do is glance grab the correct shells and the clearences are all good.

In a machine shop a competent operator can make ALL of the holes the correct size then the Crank grinder will make ALL the pins the correct size after measuring the aftermarket shells installed in the block and rods and torqued to spec.

The TRSM has a full section devoted to fitting the correct shells, so many people are building 7M's that really shouldn't be, it's not rocket science but you really need to have a grasp of what you're doing or you'll just build a grenade.

I'm not slamming you but if you're unsure/uncomfortable at this stage leave it to someone that knows what they're doing.
 
grimreaper

grimreaper

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there are a few members on here that will put the bottom end together for you. If you cant find a GREAT machine shop in your area i highly suggest it!!! I was going to go this route before i found one i feel is more then qualified.
 
CyFi6

CyFi6

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Ok i was wondering if you guys could help me directly with this. I have an 89 block that has a 6m crank in it, as far as i know its original, i was told it might be a crank from right in the weird transitioning period.
On the block i have this on one side
111 2222
On the other side
222212 (EDIT: I figured out this represents cylinder bores.)

The 2 center counterweights on the crank have numbers on them. One counterweight has stamped on it "111" The other also has stamped on it "111" (EDIT: Pictures will be shortly. I am confused on the crank, there are more numbers than i thought. Should the 7 numbers on the crankshaft supposed to match the 7 numbers on the block?)

Can you guys help me figure out what the numbers correspond to. As far as common sense, i assume the numbers on the block with 7 digits represents the mains, but as far as the other sets of 6 numbers, im not entirely sure. This engine also did have toyota bearings in it when taken apart, unfortunately i only have the remains of 1/2 of one of the main bearings, and it is stamped with a 2 on it.

Cylinder numbers:
p1267523_1.jpg

p1267523_2.jpg


First part of main bores: These represent main bores in the block
p1267523_3.jpg


Second part of main bores:
p1267523_4.jpg


Spots with numbers stamped ( 1 cut out on top not shown)
p1267523_5.jpg


These two read "111" and then "111" These represent rod journals on the crank
p1267523_6.jpg


Heres the four more spots that remain These represent main journals on the crank
p1267523_7.jpg


Rearmost set read : "1" and "01"
p1267523_8.jpg


Frontmost set read: "10" and "11"
p1267523_9.jpg



Heres the connecting rod, they all have numbers like this, but with different combinations. What do these numbers represent? All numbers besides the 2 are irrelevant
p1267523_10.jpg
 
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