Understanding Big end Bearing sizes

[StuartW]

I am confused can someone please confirm what size i need please?

 

I have just double checked the toyota TRD3000 manual on sizing.

It can be found on page 43 of the PDF here http://www.mkivsupra.net/vbb/showthread.php?t=72809

 

" If size mark on original rod bearing cannot be obtained, (As on mine)

 

add size marks on crankshaft and connecting rod cap together to

 

determine size mark of rod bearing. For example, if size mark on

 

crankshaft is "2" and size mark on connecting rod cap is "1", use rod

 

bearing with size mark "3"."

 

My Crank is stamped 101110

 

My Rods are stamped 212122

 

So surely i actually need shells sized 313232 ?

 

The confusion has come about as my Toyota dealer asked be for the number on my con rods when i was ordering the shells. That contradicts what the Reputable manual says and will mean i need 212122 sized bearings

 

Can anyone confirm this:search: please, Obviously if i have mis-understood it will blow my engine and race parts up instantly!!

 

I am confident of the main bearings being correct as they still had readable numbers on the shells and also they DID match up correctly according to adding the numbers on the other end of the crankshaft with the specification table in the toyota manual.

 

Hope someone can help..

 

Stuart (Frustrated)

Edited April 29, 2009 by StuartW (see edit history)

[merckx]

add size marks on crankshaft and connecting rod cap together to

 

My Block is stamped 101110

 

My Rods are stamped 212122

 

Big end Bearing sizes.

 

 

Are you using the numbers on the crankshaft and connecting rod cap as you've got the number on the block listed above?

Edited April 29, 2009 by merckx (see edit history)

[StuartW]

Big end Bearing sizes.

 

 

Are you using the numbers on the crankshaft and connecting rod cap as you've got the number on the block listed above?

 

You are correct and i am tired! Yes i meant Crank not Block..Will edit now Thanks

[Chris Wilson]

Your numbers are correct, although by buying ACL bearings you can forget all that stuff. If you want to be really accurate you need to use Plastiguage on each bearing as a double check.

[StuartW]

Thanks for clearing that up, I Have now had confirmation from Toyota too, So am confident to assemble..at last!

 

Cheers

[Rich8v]

I think I,ve gone wrong here. Which numbers on the rod cap do i use?

 

Theres a number on the bottom wich is part of the casting.

Then theres numbers printed/stamped on either side. I guessing one sides just the assembly guide. And the other side has a number on it.

[Chris Wilson]

Use for what purpose? You haven't got the caps mixed up have you? They MUST MUST MUST go back on the same rods they came off, same with main bearing caps and cam journal caps.

[StuartW]

Ok i have finally come to assembly 18 months later..I have bolt stretch torqued up all the big ends and #1 and 6 are too tight, Surely when using aftermarket rods the only way is to use plastiguage as the OEM rods are individually numbered and different sizes whereas the Carillo rods are all the same...either way its all going back to the machine shop so they can do it...My skills stop at replacing a standard or set +15/30 etc shell after a grind...Its too much to risk.

[greeny]

Always plastiguage them!

 

Never just use the numbers and presume they'l be right.

 

If you plastiguage them all then you can work out what clearance you have and then order the correct shells.

[Chris Wilson]

Nissan and Toyota use these bearing gradings, but we are talking microns here. If you are using a used crank forget them, the sizings will have changed due to wear. I would just buy ACL bearings and do a quick crank journal micrometer check, a quick rod bore micrometer check, and then a Plastigauge bearing clearance check. That should be more than adequate.