Main journal size mark on block
 

Hello,

I've been trying to make sense of what this means in the service manual, but haven't found a definite answer:

https://imgur.com/QsRweR5.png

Can someone help me understand?

Thanks!!

If its how Toyota does it there is a also numbers stamped on the crank. You add the number on the crank to the one stamped on the block and you get the bearing shell size used when the engine was built. I think there are about a half dozen different sizes. The rod bearing have one stamped on the rod end and the other on the crank.

Mercedes is the same way. Block is stamped across all bearings, crank is stamped at the end. There's a chart that gives you the correct main bearing sizes.

All the markings on the 2 blocks I have are 2's for the main bearing sizes.. Anyway, I've found a few threads that help explain a bit more. When I ordered bearings this didn't come into play, and as long as you're measuring the bore, the bearing thickness and the crank diameter and/or using plastiguage, you should be OK if you put them within spec.

https://forums.nasioc.com/forums/sho....php?t=2052088
https://www.ft86club.com/forums/show...?t=5778&page=2

According to Jeff, the largest difference (between 0 & 5) is 0.0005".

From my research the "Main Journal Size" stamp on the block is for manufacturing purposes only and is not a determining factor for selecting engine bearings sizes. The marking is a Subaru trait and used on older Subaru engines as well, there is some info on this on the NASIOC forum.