AE86 4A-GE swap?

[eage8]

Ok... so I'm dumb and over revved my engine last night and bent a valve.

I'm tempted just to swap the engine. I have a friend with a 4A-GE out of his AE86 that he'd probably sell me for cheap (he swapped in a silvertop).

My main question is, will all the coolant lines be in normal locations? and/or can I get parts off a GT-S or an MR2 to convert it to FWD-ness.

thanks

[Duy-]

i think the wirings going to be a bit different since he probably has a bluetop. coolant lines and everything will match up though as long as you keep your old block and head for random sensors and parts. if you have a bigport redtop you could reuse the tvis manifold and i think thats all you need to convert it to fwd

[Duy-]

personally if all you did was bent a valve id take his head and swap it onto yours. it'll save you a lot more time and hassle. if you're feeling ambitious you could pull off the oil pan and do the bearings and rings

[eage8]

Oh, I guess I should have mentioned... I have a 4A-F in there now. I don't think the coolant lines are close to the same as the AE92 4A-GE, so I don't think I could mount them to the old 4A-GE.

is the thermostat even in the right place?

this is from an '86 AE86

[eage8]

Originally Posted by Duy-

personally if all you did was bent a valve id take his head and swap it onto yours. it'll save you a lot more time and hassle. if you're feeling ambitious you could pull off the oil pan and do the bearings and rings

do my 4A-F pistons have the same compression as the 4A-GE pistons?

[fishexpo101]

They are pretty close - I believe the specs are 9.5:1 on the 4A-F, same as the 4A-FE I believe, the 4A-GE can be had with a 9.4:1 ratio for the earlier models, the later ones had 10.3:1 ratio (smallport). Assuming all US spec'd engines.

[RobMilkshakes]

Originally Posted by eage8

do my 4A-F pistons have the same compression as the 4A-GE pistons?

i dont believe they do. I remember Donald swapping GE pistons in when he did his 7afe swap

[Duy-]

not sure about the compression but yeah if you have a 4af you might want to grab a gts radiator and coolant lines. if you're going from a 4af im pretty sure you're going to need his computer as well, it'll be a pretty big job

[eage8]

Originally Posted by Duy-

not sure about the compression but yeah if you have a 4af you might want to grab a gts radiator and coolant lines. if you're going from a 4af im pretty sure you're going to need his computer as well, it'll be a pretty big job

yeah, I'll also need an EFI fuel tank + pump and a fuel return line...

I might just go get another 4AF head from the junkyard for $40

[toyotaspeed90]

Ok.... lets fix some bad info....

basically if you have an ae86 complete LB, manifolds, and wiring -- sell it to an ae86 guy.... it's all 100% useless in an ae92.

you will need all of the FWD (or MR2) pieces.... only the LB is the same (trust me I know... I have an ae86 LB in my wifes aw11). None of the cooling pipes/locations are in the same spot -- not even the radiator is the same. T-stat pipes on mr2/fwd's are in an external housing mounted on the transmission unlike in the side of the head like the F heads.

also -- the 4af/4afe has lower compression -- but the pistons are not the same.... In order to (first) find out what pistons you have you would need to pull them from the 4afe.... A series motors have 2 sized pins, 18mm and 20mm.... most 4age are 20mm, but since it's from an ae86 it would depend on year -- the early 4age's had 18mm.

compression on these is more than just the piston.... you can't take a 4age piston and put it in a 4afe block/head and expect the compression to be the same.... the combustion chamber sizes between a 4afe and a 4age are different, hence a different compression. 4af/4afe pistons tend to be more dished (like a gze piston.... but don't get them confused as gze pistons are coated and semi-forged) and ge pistons are either flat or more domed (depending on the generation).


you can do it with a 4afe ecu.... and modify the ecu (along with wiring to take a 4age dizzy... which you then have to find the uber rare JDM map 4age dizzy).... but in terms of practicality doing a wiring swap would be easier.

if you had a 4af you will also need an efi pump.