quick info needed.., from expirienced 7a engin builders.....plz Options

[mandrek]

hello all, i just have a quick question.. I'm in the process of gathering parts for a boosted 7a.. i have located a set of OEM, from the factory, Toyota 4agze pistons, and for a great price since the guy is just looking to get rid of them (change of plans..#.. thing is that they are .050" oversized..

now my question is.. is this a option that was made available to give Toyota service techs a slug that would provide tighter clearance on an old motor? #as i am suspecting# or is this an OEM replacement for use in a motor that has had to have the cylinder walls worked on #say to remove scoring) and thus the reason for the increased bore diameter..

the motor I'm looking to put these in is a 96 7a, and had 218K on it.. the walls of the cylinders are smooth as glass, and there are next to no markings showing wear. ill post a pic if need be.. but i don't think that it would be needed to answer my question..

i guess that what i am really getting at, is this... if i get these pistons will i need to have the block bored to accept these, or is this kind of o/s a tolerance check measure?

thank you..

This post has been edited by mandrek: Oct 22, 2011 - 11:24 AM

[Smaay]

everything in your post is correct. the bolt is the weakest link in the rod. the only problem is i dont know any companies that make a high performance rod for the 7A. it was never a performance engine.

1mm over is the same as .040 over and yes you can do it but you are pushing the limits of the cylinder, thats why i recommend only .020

as for pistons, i have used Diamond pistons in the past. i sent them a stock piston and for about 550 bucks they sent me a new set of machined pistons with wrist pins, rings, and clips. sometime next year i need to rebuild a friends 7A-FE and ill have to do the same thing.

[95celicastLSR]

everything in your post is correct. the bolt is the weakest link in the rod. the only problem is i dont know any companies that make a high performance rod for the 7A. it was never a performance engine.

1mm over is the same as .040 over and yes you can do it but you are pushing the limits of the cylinder, thats why i recommend only .020

as for pistons, i have used Diamond pistons in the past. i sent them a stock piston and for about 550 bucks they sent me a new set of machined pistons with wrist pins, rings, and clips. sometime next year i need to rebuild a friends 7A-FE and ill have to do the same thing.

to answer ur rod and bolt question, paughter racing sells 7a rods but going to cost you 792.00 but they come with rod.bolts rated to well over 600 hp and rods are pretty much indestructable... www.importperformanceparts.net