Engine got a question - for those who REALLY know their engines

got a question - for those who REALLY know their engines

a buddy of mine out in Cali aquired his aunt's Prizm.

it's a 1990, and it's EXACTLY the way it rolled off the assembly line. we know it's special ordered, since his uncle worked for GM at the time. it has full GTS suspension stiffening, and a not-quite-stock motor.



can anyone tell us what that motor is?

your help is appreciated

looks like a 4age smallport...sorta

is there not the engine tag on the side... should eather be on the passenger side... near the middle top of the block...

Does it say anything on the timing belt cover?

looks like 4AGE...

to those who said 4age - thanks for confirming, that's what i thought.


he didn't say anything about what it said on the engine, just that it said TWIN CAM in orange lettering.

yep, i seen that type of engine before, it is a 4AGE. the one thats definately not from japan, i think.

and omg, your sig

smallport 4age

the car is a 90-92 prizm GSI...... the non rare non-map based version...... it has the same suspension as an ae92 GTS (including front/rear swaybars, rear disc brakes, serviceable struts, and the obvious upper strut brace). GSI's also came with the larger 14" wheels, a lip spoiler on the trunk, and a red-filled geo logo on the front grill

it's a US motor.... has the EGR stuff.... (could be a japanese block, however).

it's not special order or anything.... there were a lot of gsi's produced (i live in a small town and know of at least 3-4 of them driving around)

i can go into more detail if you want.....

7 rib block, 10.3:1 pistons.... the cams are smaller than the bigport 4age's (which is a common upgrade). Has factory oil squirters, 42mm rod journals, 212mm flywheel (if it's a stick.... most gsi's are, but there are some auto's out there).... wrist pins are larger on the 7 rib block 4age's over the 5 rib...... lack of t-vis..... um, i dunno what else to say