Whats the difference?, these 7afe pistons(link) Options

[Nemises]

As some of you may know I am working on my 7afte. My question is I found these three auctions on ebay what is the difference between these 7afe pistons? What does the .020"/ .030" and .040" stand for? If I get the one with the biggest bore will lower my compression a little? Stock bore is like 81 I think the biggest one below is 82 is that enough to get a little more air and fuel into my cylinders? Does it even matter? I am getting a set im just curious.


Toyota Celica Corolla 7AFE pistons #P8059C +.020"

Toyota Celica Corolla 7AFE pistons #P8059C +.030"

Toyota Celica Corolla 7AFE pistons #P8059C +.040"

[playr158]

you want to get the pistons with a 81mm bore

any larger and you have to bore your motor

to lower compression, you have to have a custom piston made or a thicker headgasket

so none of those will fit unless you bore the motor

This post has been edited by playr158: May 10, 2005 - 4:21 PM

[Nemises]

you want to get the pistons with a 81mm bore

any larger and you have to bore your motor

to lower compression, you have to have a custom piston made or a thicker headgasket

so none of those will fit unless you bore the motor
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My fault I should have mentioned that. My car burns alot of oil so Im afraid its time for a little rebuild before the turbo. So yeah I am getting my block bored out. I know these are not low comp pistons or anything just stock. I am asking if I go with the biggest bore on one of these stock pistons can I lower my compression a little? Can i fit a tiny more boost?

Basically heres my question. I need new pistons and rings for my 7afe performance wise should i pick one of these pistons over the others (81.5 or 82) Or just get a set and get the thing bored out to match.

[FAQdaWorld]

My guess would you would prolly be able to take a bit LESS boost. Bigger displacement would mean you are getting more air and fuel burning with the same stock piston rods which is the big weakness with the 7a. So unless you were to get new rods You'd prolly be able to safely boost the same, if not less. But i doubt any more.

Compression should stay the same too.

-Ryan

[Nemises]

Thanks so basically I should get the 81.5? Or should I get the slightly bigger one 81.75 incase they have to bore out more to get all the scoring out the cylinders.

[FallenHero]

I wonder what new rods from toyota would cost... I wouldn't doubt it if they were a little better than my 1995 versions... if not simply because better materials or preparations.

[playr158]

you can get new ones online

http://www.importperformanceparts.net/
43$ a piece for new ones
you can also find piston/rod combo kits
or even a full rebuild kit

[Nemises]

Well talked to the machine shope today they told me the would bore out my cylinders for $150. Thay told me just drop off the block and new pistons and come back in 2 days.

[playr158]

what shop was that nemisis?
and ask them how much they do head work for?

cause i think thats cheaper then shops down by me

[Nemises]

It was Bouchers Auto Machine Shop Heres the link.

Bouchers Auto Machine Shop

[nik]

this is the shop doing my head work boring etc

http://www.f2uning.com/pages/10/

only $100 to bore my block out

but $900 for all the head work and there was alot done to it

[FallenHero]

$900? what, did they build you a new one?

honestly, did they have to fab new valves or something, that's kinda harsh for head work.

[nik]

sorry wasnt clear

new valves
new springs
3 angle
stage 2 port and polish
cc the chamber
port match
new retainers
arp studs
insert nuts ( id have to show you a pic)
the coolent chambers cleaned
and few other things

i need to get a pic of it up

[Kwanza26]

$900?  what, did they build you a new one?

honestly, did they have to fab new valves or something, that's kinda harsh for head work.
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Actually sounds kinda typical. Headwork is quite expensive especially when the head has to be disassembled and then re-assembled.

As for bores... anywhere from 80.00-150.00 is typical.

[FallenHero]

I thought he was talking about the machine work only, I didn't realize he was talking about new parts also.