7A-FE Rebuild., Questions on rebuilding a 7A-FE. Options

[DeviousST]

I own a completly stock 94' Celica ST, with a ticking piston (at least that is the toyota master tech's opinion), that is engine threatening. Being the glutton for punishment that I am I have decided to rebuild and improve upon my base AT200 platform. I have all the aftermarket parts figured out, where to do the build, and the equipment to do the build, so here is my problem: How do I build a 7A-FE that will be reliable with about 7 pounds of boost. Do I just buy stock toyota pistons, connecting rods, and rings? (I want to stick with the original crank) And what about the heads. Will stronger valve springs with an otherwise stock valve train make my engine more resistant to boost and rpm? Internal Engine help would be greatly appreciated.

[Kwanza26]

I own a completly stock 94' Celica ST, with a ticking piston (at least that is the toyota master tech's opinion), that is engine threatening. Being the glutton for punishment that I am I have decided to rebuild and improve upon my base AT200 platform. I have all the aftermarket parts figured out, where to do the build, and the equipment to do the build, so here is my problem: How do I build a 7A-FE that will be reliable with about 7 pounds of boost. Do I just buy stock toyota pistons, connecting rods, and rings? (I want to stick with the original crank) And what about the heads. Will stronger valve springs with an otherwise stock valve train make my engine more resistant to boost and rpm? Internal Engine help would be greatly appreciated.

You need to do your research on what boost does to which parts... Boost = heat... the parts most associated with failure due to heat are the rods and pistons and associated bearings. If you're gonna do a true rebuild for boost... don't bother with OEM pistons... however... low-comp pistons, which generate less heat during compression, are pretty much mandatory for a boost build. The stock rods will probably be fine with around 7-10 pounds of boost, but an upgrade is always nice since the 7A rods are kinda dinky. You don't need to worry about the crank... at all.

As for the head... the head is unaffected by boost in terms of durability. Valve spring upgrades are done if you plan on revving the engine high... so they're not needed in this case. Beyond that... you worry about your tune and your fuelling, which is as important to reliability and durability as is the mechanical.

[DeviousST]

Yeah the pesky car has an automatic transmission too. So one day I know I'll be changing that bad boy out. But now I guess I get to dig around for some good 7A pistons. When rebuilding the heads do I stop at new valves, guides, and springs? Thanks again for the help.

[SinisterWhisper]

If your going to go through all the trouble of rebuilding the engine why not just drop a different one in? Perhaps look at getting a 4age?

[DeviousST]

Well I didnt quite feel brave enough to go beyond my base platform. I saw a complete engine at a local junkyard the other day sitting in an 89 corolla gts, and I was kinda wondering if that was a 4age, but they want $500 dollars for it all. It just seems cheaper in the long run to stick with 7A-FE. And I'm pretty damn cheap

[laff09]

for 500....complete? thats pretty cheap. Forged pistons run what ~$300? and forged rods are more than double that iirc

[DeviousST]

Do you thing its a 4age then? I'm kinda clueless, it had a red stripe down the middle. And no matter what I have the rebuild the 7A bottom, then restore the head.