Bottom end

[corolla-18's]

how can we build the bottom end of the 7-afe to be reliable, what can we do to it, i mean what can we buy as far as parts go

[Flashmn]

You didnt say what kind of mods you want to do. For a stock car the stock stuff are reliable enough.

[Piloter]

Reports are conflicting on the bottom end reliability anyway. Popular wisdom--relatively unsubstantiated--seems to be that the conrods are weak, yet a lot of people who have built 7AFTEs or 7AGEs seem to have run stock rods up to 7K RPMs on a regular basis without issue and are bewildered at the weak rod claim. Reports of success are prevalent across all the forums I've trawled for 7AGE information, and actual anecdotal reports of failure are scarce. It seems that anything up to about 8 PSI or a G-series head swap on the stock bottom end may be OK to run.

That said, custom rods are always possible to get made up. By the time you're making enough power to need a custom crank, you'd be an idiot to be doing it with the 7AFE bottom end anyway and would be MUCH better off sleeving a 4AGZE block and overboring it before doing a 5AGE stroker conversion. (Or the inline-4 Toyota holy grail, the 5SGTE...)

As a rough rule of thumb, if you're going to be making much over 220 horses with the 7AFE bottom end, go for ARP conrod bolts, get the stock rods peened and maybe oil squirters cut in them. Over 300, then you'd probably want to get custom rods...

Of course, with 300 horses out of a 7AFE, the investment for custom rods is going to be the least of your expenses. =)

[Flashmn]

On tuned engines, connecting rods often fail when the throttle is slammed shut, creating a vacuum inside the intake side, this tries to pull the piston up when the connecting rod is pulling it down, but the connecting rod then snaps.

Connecting rods are designed to withstand the force of the piston pushing downwards on it.

[94_Rolla_Guy]

Ok i could add to the Con rod arguement, when i first got the car i accidentally mishifted into 2end on the highway the tach went off the scale i must have spun the engine to like 9000 rpm for a split second, surprisingly nothing happened...

[Flashmn]

Connecting rods dont usually snap due to over revving. Usually the damage happens to the valvetrain and in interference engines they might smack the pistons.

[corolla-18's]

i want to build it up for a turbo set up, nothing over 10psi, but somehting to have fun with around here to make the hondas and acuras trimble in there boots, and im gonna be swapping in a 5pd for my auto so that why i was wondering what i can do to my bottom end or what other bottom end will bolt up considering that i already have another engine, but i havent even touched it yet, it too is a 7afe, picked it up for cheap, or any other suggestions would be appericated

[Piloter]

Try checking out www.6gc.net , the 94-99 Celica ST had a 7AFE and seems pretty popular to turbo. There's lots of good build diaries over there and helpful tech advice. The turbo of choice seems to be the T3 Super 60, although you'll probably have good results with a T25 or T28 as well. Hopefully your engine is in good running condition (high compression, no sludge, not some ridiculous number of miles)...because if you turbocharge a poor-running engine, you're pretty much guaranteed to destroy it way before its natural time.

Also thanks for the throttle overrun tip, Flashmn.

94_Rolla_Guy, that must have been a bit of a terrifying moment. Makes me glad I've got an auto. =)