Bearing selection

[TheNewRed]

Hey guys, i just measured out my crank and im having a hard selecting which Toyota bearing sizes i should get. It seems like they(toyota) could get the numbers mixed up b/c if im not mistaking they have 9 different "standard" sizes, two of which are the size "2", three of which are the size "3", two of which are "4", the others are a "1" and a "5" size... I just think im really confused with Toyota's way of labeling these things. I also wanted to know about clevites, would they be an ok alternative?
Heres the pages im using as a guide: http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=EM&P=72
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=EM&P=73

And my crank main diameters measured out like this(im particularly con cecerned with #7):
1. 2.3625
2. 2.3624
3. 2.3625
4. 2.3620
5. 2.3621
6. 2.3620
7. 2.3619

Rod pins measured like this:
1. 2.0464
2. 2.0464
3. 2.0465
4. 2.0464
5. 2.0466
6. 2.0464

Thanks ahead of time!

[TheNewRed]

Helloooo? A little help would be awesome lol

[CyFi6]

Problem is very few people actually do the bearings properly, therefore very few people know anything about it. I have asked questions about these bearings and you need to be patient when waiting for answers because not many people understand the system. Have you looked at the numbers stamped on your block and crankshaft where it shows in the tsrm?

[Clip]

doesn't really pertain to your problem but hope it helps: i've been using clevite 77s for almost 10k mi now with no problems, but my crank is ground .010 under so the crank should've measured close.

not sure what you're having trouble with, when i was first looking at my block and crank i was able to match up block/crank numbers and find the bearing number from the chart.

[Jeff Lange]

There are 5 rod sizes and 5 main sizes. You've only posted the sizes of the crank, not of the rods and the block, these numbers are also required to know bearing size.

crank main diameters
1. 2.3625 (0)
2. 2.3624 (1)
3. 2.3625 (0)
4. 2.3620 (2)
5. 2.3621 (2)
6. 2.3620 (2)
7. 2.3619 (2 -- This is just beyond 2, should be 3, if there was a 3. It's probably fine; use 3 if you can, if not, use 2)

Rod pins measured like this:
1. 2.0464 (2)
2. 2.0464 (2)
3. 2.0465 (2)
4. 2.0464 (2)
5. 2.0466 (2)
6. 2.0464 (2)


Once you have your block measured and your rods measured, you can get the numbers for those, and then add them together to get your select-fit sizes.

Jeff

[suprarx7nut]

The select fit system is really quite simple once you get where the numbers come from, but it has taken me some serious thought time to wrap my head around the system.

Measure inside of hole, outside of hole peg/rod. Add the appropriate select fit numbers together to get your bearing number.

[TheNewRed]

Alright awesome, i just didnt know if there were like two "#2" size bearings or like three "#3" size bearing or what. but i think i got it now. calling Rich tomorrow :biglaugh:

[Jeff Lange]

Alright awesome, i just didnt know if there were like two "#2" size bearings or like three "#3" size bearing or what. but i think i got it now. calling Rich tomorrow :biglaugh:

That wouldn't make any sense, haha.

Jeff

[TheNewRed]

That wouldn't make any sense, haha.

Jeff

I know but if you look on the TSRM in the links i posted they do have it that way hahaha??? Look at the chart on the bottom of the link i posted the way they say to see what size you have could be a combonation of different sizes for both the pin diameter, and the main bore?
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=EM&P=72
For ex: if i wanted to use a #2 bearing and my block is a 2 and the crank is a 0 i would use a #2 bearing, but which number 2 would i use... they have two of them listed at the bottom of their chart?

[CyFi6]

Theres not two different #2's, you are just using the same bearing in two different instances.

[Jeff Lange]

They're just saying you use a number 2 in either case. Number 2 is just a specification for the thickness range of the bearing, it is used to make the correct clearance between the crank and rod/block.

Jeff

[CyFi6]

By the way i just measured a set of standard size NDC and King bearings i had and compared them to sizes in the TSRM. The STD size bearings are a full .001-.0015" thinner than the smallest listed bearing in the TSRM. I don't understand how people are getting away with slapping STD size bearings in.

[TheNewRed]

By the way i just measured a set of standard size NDC and King bearings i had and compared them to sizes in the TSRM. The STD size bearings are a full .001-.0015" thinner than the smallest listed bearing in the TSRM. I don't understand how people are getting away with slapping STD size bearings in.

Ok i understand now, thanks to you and Jeff, thanks!!!

I agree, thats why im going with Toyota. I wasnt comfortable at all with clevites although i know they are widely used on our engines, but they couldnt even give a close enough tolerance for me, let alone NDC or king. For something as important as keeping a film of oil .0012in thick on a 50lb hunk of steel at speeds of 8000RPM Toyota's bearings begin to look a lot more favorable.

[CyFi6]

Right, Toyota is the way to go. Standard sized bearings can be used but you are supposed to do machine work to allow them to fit, only problem is most people don't.

[TheNewRed]

Right, Toyota is the way to go. Standard sized bearings can be used but you are supposed to do machine work to allow them to fit, only problem is most people don't.

Yep, thats what i figured. Have the crank reworked, and the mains resized and straightened, and good luck finding someone trustworthy to do it, I know it took my ass three months and six hours of driving to find Rich lol, and i wouldnt trust my stuff with anyone else for the amount of money it takes to have these things done!

[Jeff Lange]

If the standard size aftermarket bearings are slightly thinner than the thinnest ones Toyota offers, that's perfect for a "cheap" build (if you were doing such a thing). Toyota's spec for max clearance is quite a bit higher than their standard sizes. With a thinner bearing, no matter what size your block, rods and crank are, you'll still be under the max limit specified by Toyota, even though you won't be within the "perfect" Toyota specification range.

EDIT: Also, if they're thinner, there's no way machining anything would make them fit better, only more clearance, which will take you further away from spec.

Jeff

[TheNewRed]

Thanks Jeff, you've helped me a lot!

[JDMMA70]

I want to chime in with a question, i understand the select fit bearing system, but im alittle confused on how i would go about selecting a bearing if my crank gets machined or my block gets aligned honed (for ARP Studs). Do i just Mic everything and then select a bearing that falls within the measurments? Sorry if this is a dumb question just want to be sure i do everything correctly when it comes time to rebuild my 7M

Thanks
~JDMMA70

[CyFi6]

Well if you have your crank ground you need to fit undersize bearings (Thicker bearing wall). Your block and rods should be resized back to an equal size (whatever your bearing calls for) and then your crank ground based on the bearings etc. If you have your crank ground its obviously going to be smaller, so you cannot use Toyota bearings.

[a_sesshoumaru]

my crank is standar and i have put ndc bearing standar size 3 times, everytime i checked they were as new. I have not had rod knock problems with this crank and ndc beargins, and my engine has seen 23psi everyday.

[CyFi6]

How many miles were put on them? Remember that toyota's engines are made to last 150, 180, 200,000+ miles, so a short mileage on an engine with new bearings wont tell the whole story.

[CyFi6]

Im having some trouble understanding the bearing system again... Need some help. I will use an example here. Say i have a #1 main bore in my block (2.5206") and a #1 Crank journal for that main (2.3622"). That would mean i would need a #2 bearing (.0784" Thickness) correct?

Well in order to figure oil clearance, i would need to do this equation.. B=Block main bore, C= crank main journal, Bear= bearing size (thickness)

B-Bear= (C+.0012" to .0019" oil clearance)

2.5206"-.0784"= 2.4422"

2.4422"-2.3622"= .080" Now why in hell would i want .080" oil clearance?

Please someone help me out...i feel like im doing something wrong here...
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=EM&P=73
Theres the chart with the bearing numbers, crank numbers, block numbers and measurements.

If my C and B are the sizes mentioned above (both #1), with a .0018" oil clearance, my bearing center wall thickness would need to be .1566" according to my calculations, which is not an offered size

Edit: I think my errors are because we are dealing with a circle, which means certain numbers will need to be doubled or divided by two etc... now im just all confused..

[Jeff Lange]

The bearing thickness needs to be doubled, because it is on both sides of the journal.

Jeff

[Mad-Dax]

I want to make sure for myself that the numbers I am looking for on the connecting rod is what is on the side? I have the 3 number and letter combo that is partially stamped on the side of the cap and the rod (to match them up). I am not looking for the single number that is embossed on the very bottom of the cap right?

[rayall01]

I want to make sure for myself that the numbers I am looking for on the connecting rod is what is on the side? I have the 3 number and letter combo that is partially stamped on the side of the cap and the rod (to match them up). I am not looking for the single number that is embossed on the very bottom of the cap right?

Correct. the # on the bottom of the cap has no relevance to bearing selection.