4AGZE bore clearance?????

[ENKI]

Ok i know for the ae101 ze piston clearance its 0.12-0.14mm but my engine builder is adament that its too much. Can anyone explain why so much as my mechanic has built some pretty crazy engines and has never come across this much clearance even for full aftermarket forged pistons?

Nick

[HRV-00S]

Anyone? I need to know to

[Rallystanza]

Are you saying they are aftermarket forgies?

If they are ARIAS, ARIAS runs the largest piston to bore clearance out of the aftermarket range. All Forgies will have a larger clearance due to the sweeling of the piston when up to temp, hence the forged piston rattke on cold start up.

This is all been told to me by my experience engine builder who also commented on the large piston the bore clearance on the ARIAS forgies that I am running in my Turbo 4A.

[Mr Revhead]

have a search for the specs... they have been posted on here straight out of the manual.
then you can check the specs you have are correct

[ENKI]

i Know they are correct but does it not seem a bit high???
It must have something with the design of the piston where it is larger on top than the bottom or just has a larger volume on top that modern pistons????
Thats the best explaination me and my mechanic can come up with???
Any ideas anyone????
sorry about the anchient reply, havent had a computer for a while due to it dieing!!!

Nick

[feral4mr2]

All Forgies will have a larger clearance due to the swelling of the piston when up to temp, hence the forged piston rattke on cold start up..

thats the way i understand it too.

[wa5]

On a similar note I have a scored bore in an 87 4age what is the safe maximum overbore on one of these?

[Mr Revhead]

yeah, forged = larger clearance.
as to what typical forged pistons have, thats outside my expertise.

0.5mm is the largest stock piston size. but that doesnt mean you cant go aftermarket and larger.
1mm is a figure in my head for some reason... but you need to conform that

[feral4mr2]

yea 1mm i think is the 'safest' overbore. though people have gone to a 83mm bore (2mm over) and used ca18det pistons, was a popular thing in japan for a while i think. was going to do it with my scored #4 cylinder bore block until i was told ca18det pistons were cast??
have a set of 8.9:1- 0.5 OS gze pistons now, so all's good.

[ENKI]

Yeah i understand the concept of a forged piston expanding and so forth but wat im saying is even for a forged piston it sounds very high.
My mechanic recons he has installed aftermarket pistons (not sure which brand) in a motor and has only ever had a clearance of about 0.05 i think 0.08 was the highest he has ever gone and he builds boat racing motors and a few spastic cars.

Nick

[HRV-00S]

So the 0.12-0.14mm is for the standard gze pistons NOT after market forgies is that correct. I've done a search and all that comes up is the 4age which is no good for the gze pistons. Is this defiantly the right clearance can anyone confirm it?

Cheers Dan

[wa5]

Thanks for the info

[cri_ag]

search dude i posted the piston to bore clearances for a gze not that long ago, i got the specs from toyota japan from there gze manual. (and it took a fucking long time and a lot of overseas phone calls)

[cri_ag]

http://www.toymods.net/forums/showth...highlight=4age

go down the bottom. they are the specs my motor was built to.