project ae92 7gen LE

[MJW69]

hi my name melvin i drive an 88 ae92 SR5, which i will be changing over all i can from a 1994 corolla LE with the 7afe. i have been looking every were for the answer, will 4agze pistons fit in the 7afe,and with what mods ,gas,and will i need fuel computer? thanks ahead

[Evo_lucian]

4agze pistons will fit with no mods. No fuel computer needed. You will just get a lil bump in compression

[MJW69]

will the 4agelu pistons fit that is all i can get, they say there the same as gze i'm not sure. but i belive i'm looking for a 20mm pin size right.

[Blof-fan]

I guess you're are talking about pistons from the Smallport (aka redtop) 4A-GE. They use the 20mm pistonpin, and have a higher compression ratio than earlier 4A-GE's (earlier 4A-GE's 9.4:1, later 4A-GE 10.3:1)

But those pistons are not the same as the 4A-GZE pistons. Later 4A-GZE's only have a compression ratio of 8.9:1, have a different shaped top and are teflon coated for better risistance against added heat etc.

To make things even more complicated. Don't stare yourself blind on the pin size. Some later Bigport (aka Bluetop) 4A-GE's use the same 20mm pistonpin

Are you going to swap out the head of the 4A-GE with the 7A-FE to create a 7A-GE?

[Donald]

Originally Posted by MJW69

hi my name melvin i drive an 88 ae92 SR5, which i will be changing over all i can from a 1994 corolla LE with the 7afe. i have been looking every were for the answer, will 4agze pistons fit in the 7afe,and with what mods ,gas,and will i need fuel computer? thanks ahead

Hey Melvin,
If you want to boost the compression of the 7A-FE, you can order pistons for about $600 for the set, including rings and I think pins also. They will be custom made to the compression that you want. I will have to look up the address. I really don't know what kind of power/torque increase those will give you. I haven't been able to find anyone who has upped the compression of the 7A.

I have 4A-GE pistons in my 7A-FE, but I don't think I gained more than a few points of compression, because I had to use a thicker head gasket to get clearance between the valves and the pistons, trying to keep it a non-interference engine, since the reliefs in the piston crowns are different.

To do the engine swap, you will need:
GT-S fuel tank, or mount an external inline fuel pump. (The inline pump wil limit you to not going below 1/4 tank, without risking fuel starvation when cornering)
Electric Control Unit (engine computer) and wiring for the 7A-FE engine.

The 7A-FE engine and gearbox will fit right into your car. The exhaust pipe might be the only snag here, but that is easily rectified by any muffler shop.

If you just use the 7A-FE engine, you old gearbox will bolt to it.

[MJW69]

thanks donald, I will probably just do the 4age piston. I'm buying a1994 corolla LE for all the parts, my plan is to swap every thing over to make my ae92 carby into ae101, brakes,motor,struts,sway bar,etc... donald did you thank the 4age pistons are worth it for the little bit of cr bump?

[Donald]

Originally Posted by MJW69

thanks donald, I will probably just do the 4age piston. I'm buying a1994 corolla LE for all the parts, my plan is to swap every thing over to make my ae92 carby into ae101, brakes,motor,struts,sway bar,etc... donald did you thank the 4age pistons are worth it for the little bit of cr bump?

Unfortunately I never drove the 7A-FE engine with the stock pistons, so I have no baseline to compare with.
After installing the 4A-GE pistons and realizing that I had to use a thicker head gasket to get clearance, I would have gone back to the original pistons, except they had to have the wrist pins pressed in, and I had to pay for that.
There was running clearance using the 7A-FE (thin) head gasket with the timing belt installed. But without the timing belt, when I turned the crank there was hard contact, so I decided to play it safe and use the thicker (4A-FE) gasket. I don't know how much clearance that gave me, but I could turn the crank without the timing belt without making contact with the valves.

Just looking at everything assembled, I believe that the compression gain wasn't worth the effort. I don't think I got more than 0.2:1 increase, maybe less.
Whenever I get the chance, I plan on putting the car on a dyno to see what it actually puts out.

Shaving the head a few thousanths will probably be a better way to get compression ratio increase than using the 4A-GE pistons.
The best way though would probably be to get the high comp pistons.

I believe that this link is where I got the quote on the 7A-FE high compression pistons

http://www.nolimitmotorsport.com/wiseco/

[Donald]

See my thread on the brakes.

AE92 Front Brake Upgrade

You want to swap the hubs from the 94 into your steering knuckles.
The bearings are the same diameters, actually the same bearings.

Evewrything else from the '94 brake system will fit on the '88 steering knuckle after you swap the hubs.

[MJW69]

i here you,but i'm planing on the hole suspinsion so i can use the front sway bar. I'm also goning to try and use all of the steering,tie rods,lower control arms,and column. if i use the rear brakes from the ae101 i well also need to chang the p valve? they are drums from the LE

[MJW69]

Thank you donald,i'm not shure if i well be doing the 4age pistons i belive i can get a rebliud kit for 7afe with pistons for $240.00,and you said 4age pistons from the smallport? not shure about $.

[Donald]

Originally Posted by MJW69

Thank you donald,i'm not shure if i well be doing the 4age pistons i belive i can get a rebliud kit for 7afe with pistons for $240.00,and you said 4age pistons from the smallport? not shure about $.

No. You don't want to use Smallport pistons in a 7A-FE. They have a higher compression than the Bigport pistons, so I believe you will have a greater interferance problem than I did. I used Bigport pistons.

Like I said before, to boost the compression of the 7A-FE, I would only suggest shaving the head (cheaper but lower gain) or just ordering high compression 7A-FE pistons ($$).

I have rebuilt 3 "A" series Corolla engines and have another 2 blocks and pistons that I have measured, and none needed pistons. So I would suggest not to buy pistons until you have got inside and measured. Why spend more money than you need to?
I would just replace the rings and bearings. Most of the bearings that I have looked at were still very good, but I replaced them just because I was in there.

Are both cars 5 speed, auto, or are they different?
What transmission / gearbox are you planning on using?

I just realised that you are in Concord. What you might wan't to do if you are planing to use the 7A wiring and ECU, is send both wire harnesses to Dr. Tweak at PheonixTuning.com (somewhere in SC) and he will make a plug-and-play wire harness for you for about $400, I think.

Our Club is having an autocross event at the Old Sanford Airport on the weekend April 17 & 18. I plan on being there, (not sure if both days yet) maybe you could come out there.

[MJW69]

mine is a 5speed and the LE is an auto. i have a 10lb fly wheel, stage 2 clutch,intake cam advance one tooth,stage one weight reduction,and the rest is 22 years old stock. i would love to go, were is that at [pm] me with more info thanks