[Mk2] [Turbo] what do the numbers stamped on my block mean???

[castrolfan]

Hey guys,

Im just getting ready to re-build my engine but want to check something first...

my crank has five 0's stamped into it which i would guess means its the standard size and has not been ground at any time.

on the underside of the block (the flat part where the sump bolts on) has five 1's stamped into it... this is for the big ends maybe, i don't know

and now the most confusing thing!...on the top of the block (under the head gaskit) in front of each cylinder is a number. Cylinder 1, 2 and 4 have a number 2 stamped infront but cylinder 3 had the number 1

anyone know what this is all about? iv measured all the cylinder bores and they are all the same

any info would be great

[Quigonjay]

i'm guessing they are just factory assembly references and mean nothing to you or i

[Slarty]

They're probably grading numbers for the main bearing, pin bearings and bore sizes. Most likely with 0 being bottom tolerance and X (I obviously don't know their upper number!) being upper tolerance.

As Jay said, they're of little use to you unless you're buying replacement stock sized bearing liners or pistions/rings.

[castrolfan]

i am, i need to replace all the pistons and rings and the big end bearings.

[castrolfan]

i found the answer in a toyota work shop manual...

Cylinder bore diameter is determined by size mark on
cylinder block deck surface. See Fig. 30. Maximum
bore diameter is 3.3949" (86.230 mm).