GE pistons in a 7A-FE?

[94_Rolla_Guy]

I had a thought about possibly using GE pistons in a 7A-FE to obtain a higher compression ratio, something around 10 - 10.5:1 up from 9.5:1 My goal is to get a nice reliable 7A-FE the reason id like to do this is because i doubt i could figure out the electrical to do a swap to a 4A-GE small port or what not. My concerns would be which pistons to use?, do the fly cuts meant for GE valves work for FE valve configuration. Also if anyone knows the displacement of GE and or FE combustion chambers this would also help

[Pineapple]

4A-GE - 1.6L
7A-FE - 1.8L
Possible bore different size.

[Kwanza]

Bores are the same but pistons pins are slightly different between the 7AFE, early model 4AGEs and Late model 4AGEs. Also, because of the FE head design, you won't be able to run high-comp 4AG pistons because compression would be too high. Tests have shown that 4AGZE low comp pistons make about 10:5 compression when matched to the 7AFE... so you can only imagine the kind of crazy compression you'll get if you chose to run stock 4AG compression or even higher comp pistons. It's safe to say the 7AFE compression chamber volume is significantly smaller than the 4AG's... The flycuts shouldn't matter too much. It would be nice to match up the cuts, but they won't interfere with normal operation. The piston of choice should be 4AGZE pistons because they're really the only ones that will make useable compression in the 7AFE (with pump gas).

[4Aaron GE]

Fred, it's only a stroke difference.

[94_Rolla_Guy]

that sounds about right to me aswell, to add i was just wondering of anyone knows where i can get all the internal dimensions of the A series engines. id be looking for like center to center of the rods, compression heights, main journal dia, small end bore (rods) stuff like this...

[Pineapple]

Originally Posted by 4Aaron GE

Fred, it's only a stroke difference.

Roger that.