Engine Block #
 

No, I'm not asking for name of the engine.

So while I was reading Japanese 86 site, I read that, in the engine block, there are a five digit numbers plus a four letter.
Example:
22222 BBBB
232323 ABAB

They said that, if you have all the numbers & letters same, better the quality of that engine was built.

There were few owners w 22212 BBBB, 21122 BBBB, but most owner had 22222 BBBB

so just wondering how's US or other country FRS/BRZ/GT86 owner engine built was

That's for piston to bore fit on Subarus or something?

Idk, the forum starter didn't explain enough. Just ask what everyone has on the block

Some of the Subie guys can probably clarify but I think it has to do with making sure the right pistons go in the right bores when the engine is being built. I guess ideally if they were all the same the motor could be better balanced, but that's pretty extreme.

I thought I'm a Subie guy, but man I must be not a Gearhead than I've thought. I need to go back to garage & study more lol

This probably doesnt translate to Subarus, but the Honda J series has a stamp in the bottom of the block that coincides with the crank bearings.

Typically numbers like this on the block will indicate cylinder bore sizes and crankshaft main bearing bore sizes. If the numbers and/or are all the same, then the block is "more precisely" machined, and all of your sizing is the same.

It honestly doesn't really matter though, as what these are actually used for is to correctly select the bearings and pistons to give you the correct oil clearances, which should be consistent across all engines.

Jeff

That would seem to matter if you replacing those parts.

To throw some more fuel on the fire, it could indicate how well the different parts of the mold were lined up during the casting process. I know older engines sometimes had trouble if they were being bored out and the casting didn't line up well, the cylinder walls would be too weak.

Correct, it matters when replacing parts. There will be markings on the crankshaft that also indicate the journal diameters for the mains and rods and markings on the rods as well. If you are replacing these parts you will use these markings to know which bearings and/or pistons to order to maintain the correct clearances.

Jeff

The letters are for the bores, so I believe the numbers are for the main bearings.

Correct, there are 4 pistons and 5 main bearing journals. :)

Jeff

where exactly on the block is it?

Let me check the Japanese forum...

He said
"Center of engine block below engine throttle."