4A-GE engines? what a mess!

[robokill]

Ok lets start from the top

Standard AE86 (GT/APEX/GTS) where sold with a

Bluetop 4A-GE Bigport engine with 40mm crank and 18mm piston pins

the block has 3 ribs

Then second blocks from 87-90 are 3 rib smallport blocks actually already (redtops) but not yet the full thing you want for tuning

then we have the best of the bill late 90 to 91 is a

redtop 7 rib smallport map sensored 42mm crank 20mm piston pin 4A-GE

92 AE101 4A-GE Silvertop not sure about crank lower block is similiar to the 7rib last version (its the same almost) and the head is difrent 5 valves
only AFM

97 AE111 4A-GE Blacktop Map sensored little boosted up to his older brother but not that difrent but difrent size pistons pins etc

Or the ribs are the lowerblock ribs they are vertical lines along the block it is for strenghting you can see it as a strap around a piece of cheese :-)

more ribs stronger block simple

Matter of valve covers peepz paint those so doesn't say a thing

big port refers to the head of the engine big port is a full round circle and a smallport is euhm how do you say it OVAL ???? its like an egg but then symetric :-)