stroking the 4a block

[ae102geo]

I know the bores are the same on the 4age and 7afe so what were to happen if I put a 7afe crank and rods in a 4age block? besides the 200cc difference

[94_Rolla_Guy]

the pistons would come about 15mm out the top of the bores! if you want the stroker 7A advantage get a whole 7A bottom end and do a 7A-GE hybrid...

search "7A-GE" here and google you will find quite a bit of info!

the only other thing you can do is to try and find a HKS 5A-GE kit that makes 1.8L on a 4A-GE block! but... hard to find and rather expensive!

[ae102geo]

ok all of that looks good except for one thing. everyone says the 7a bottom end is week. i noticed that the 2zzge engine revs to nearly 8,000 and can go past, and the stroke is the same length. could the 2zzge crankshaft, rods pistins be swapped into a 7a block. The bore doesn't matter I will get the blocked honed and bored if need be.

[toyotaspeed90]

no... not all is good.... the 7a has a longer stroke, yes... but it also has a taller block.

more than likely you'll smash the pistons into the head

[REN69]

Where did you hear the 7A bottom end was weak? The whole reason to build a 7AGE hybrid was that the 7AFE had a stronger bottom end than the 4AGE, the 7AFE bottom end would be able to put out more torque IMO.

Like rolla_guy said.. search for 7AGE, Rolla pat from Montreal has done this conversion on his AE86 and its putting out some decent power.

[ae102geo]

"With longer crank stroke, the 7A-GE’s cannot be revved as far due to known failures of connecting rods and bearings. The maximum power band usually falls at as little as 6800rpm, a sign of internal stress, meaning it’s way-past the physical redline… Most tuners recommend its use below 7500rpm"
http://www.club4ag.com/faq%20and%20t...20and%207A.htm

[toyotaspeed90]

yeah, ren... the 7a's crank is actually weaker than any 4age.... all of the 4age cranks are forged, wereas the 4afe/7afe's aren't

i wouldn't be surprised if toyota used the smaller journals on the 7a crank much like the 4afe cranks got....

[ae102geo]

http://www.billzilla.org/starleteng.htm

what do you guys think about the first two engine and the one at the bottem in the buggy

[cuzman]

For all the stuffing around get a 4agze...cheap and easy and has even more torqe