4agze/fe pistons in a 7afe

[Poggy]

Hey guys,
Well i'm rebuilding/spicing up my 7afe, yeah i know what youre going to say " Why bother" but anyway, i'm looking to knock the compression up to around 11, there are a few ways that came to mind.
1. Use a 4agze flattop 40/60thou piston plus headshave, sleeve my 7afe conrod and use full floating. " this will produce a higher comp then the 4afe piston"
2. Use 4afe 40/60thou piston plus headshave which has less dish then 7afe, would also convert this to full floating.

I wanted to go to a drop forged piston, or something a little stronger then the standard 7afe piston.

One big problem i'm looking a is the valve cut marks in the top of the pistons, on the 7afe they are deeper towards the center, on the ge pistons is different due to the valve angle, i know it wouldnt really pose a problem unless a timing belt snapped, but what do you guys think? would the gze piston be a better option, also can i can aftermarket conrods for the 7afe, something a little stronger.

Cheers.

[The Witzl]

dunno about piston-to-valve clearance issues with the 4A-GZE pistons, but they would be my number 1 absolute choice.

Factory forged, and $400 a set from Toyota.

[4agte]

are you going forced induction or n/a cause arent the factory gze pistons rather heavy

[The Witzl]

http://forums.toymods.org.au/index.p...t=0#msg_200356

... looks to be around the 300g mark without pin.

[Ben Wilson]

1. Use a 4agze flattop 40/60thou piston plus headshave, sleeve my 7afe conrod and use full floating. " this will produce a higher comp then the 4afe piston"

Ze pistons aren't flot top, they have a dished top.

[Hiro]

http://forums.toymods.org.au/index.p...t=0#msg_200356

... looks to be around the 300g mark without pin.

Sounds about the same as a 7A piston anyway, at least the one that I modelled.

[4agte]

http://forums.toymods.org.au/index.p...t=0#msg_200356

... looks to be around the 300g mark without pin.

what was left of MrShins piston weighed 298.12g

so that means its the full weight of a piston intact.......?

[Poggy]

Ze pistons aren't flot top, they have a dished top.

sorry what i ment was there are two 4agze pistons, one is dished, the other is slighty dished close to flat top

Its going to be n/a, the 4agze piston will be better in my mind, due to the full floating, it wil lsnap/rev quicker

[oldcorollas]

piston weight for GZE AE92 0.5mm oversize

about 305grams

pin weight = 100grams

total, about 405 grams

the vague weights of pistons posted by Kingmick (even though he never bothered to post if they included pins or not ) indicates that other aftermarkets are lighter.... but bang for buck...
the dish volume should be easy to find also.

[4agte]

righto cheers for that i had the impression that they were alot heavier +rep

[oldcorollas]

and in that other thread, Ben Wilson showed the blacktop 20V pistons (including pins) were abotu the same weight as the GZE slugs!!! (so rep him too ), but he suggested the silver top ones were lighter...

[Poggy]

arias makes an 82mm "flattop" piston Comp ratio with stock head is 8.6:1 it has a dome CC of -4.3 that should make the comp ration around 10.8:1 - 11.1:1

[Ben Wilson]

and in that other thread, Ben Wilson showed the blacktop 20V pistons (including pins) were abotu the same weight as the GZE slugs!!! (so rep him too ), but he suggested the silver top ones were lighter...

Every factory 4AG piston I've found reference to is around the same weight.

[Poggy]

gze pistons will knock the comp ratio up around 1.5:1

[Cameron_Datto]

From what i have read the conrods are more the worry , rather than the pistons , personally i wouldn`t change the pistons if you still got Std 7a rods . oh well its your engine So its your call on what you use , my 2 cents