Which 4A is best?

[danzo]

This coming week Pick 'n' Pull is having a 20% off engine sale. They are a national chain so there may be one near you (no I am not a paid endorser). So I've been kicking around the idea of slapping in a 4A, but I'm looking for some advice from the good peeps here who have done it. Is there a 'best' year/model of donor car? E.G. one that requires the least amount of extra parts/mods for the swap.

If I do this swap of course I'm going to rebuild the motor before it goes into my car, or at least tear it down and check everything. I've always wanted to build the motor in my car if for no other reason than to be able to waltz around dinner parties gingerly sipping a martini whilst casually mentioning that "my engine is a danzo original".

Thanks in advance and continue having a great Siete de Mayo.

[dlb]

i'm certainly no expert but from what i read before i did the swap, the 4A series is much like the 3A in that it came with a bunch of different emissions packages which were indicated by different additional letters--4A-C, 4A-L, 4A-LC. so any carb'd 4A will fit in with minimal effort.

wait, just realized you might mean all 4As, like the 4AFE AND 4AGEs. i don't know a ton about them but i was chilling with disco quinn (who just joined our forum) and he knows a ton about 4AGs. he gave my dad some info on them in an email, which my dad forwarded to me, which i will put here:

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You have a redtop - small port 4age, which, for north america was the best 4age available. Japan continued to produce the 4age through until 1998. '93 saw the introduction of the 20v silvertop version of the engine and I think it was 1996 that the blacktop 20v 4age came around. The redtop you have produces about 120hp stock, where the silvertop 20v made 150hp and the blacktop made near 170hp. All 4age's had a hole for a pilot bearing. There is also a factory supercharged version that came in first generation MR2's in North america and Japan, as well as Corolla Levins and Truenos in Japan. It makes roughly 165hp and has a bit more low end torque.

basically it goes

16v 3 rib bluetop 115hp
16v 7 rib bluetop/redtop large port 115hp
16v 7 rib redtop small port 120hp
20v silvertop 150hp
20v blacktop 170hp.
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personally, i can't be bothered with all the work of putting a 4AG in a terc. the carb'd engines work fine for my needs so i don't want to make more work for myself. i understand petros and synth's desire to make our cars into an even more superior machine but they have far more experience and knowledge with this stuff than i do so i leave the engineering adventures to them.

hope that helps!

[Petros]

I would not consider a 4age or 4afe swap an easy project, too many custom parts to fab, a lot of messing around with electronics, fuel system, etc. I consider it worth it to have "petros original" in my car, but I would not recommend it for a typical weekend wrencher.

All the same year carbed corollas carry the 4ac, which is an easy swap over. Doing it in conjunction with a rebuild is not a bad idea, or at the very least new bearings and rings (along with the Petros head gasket modification). You will want only the 4ac long block, you will have to swap over your water pump and heater lines, oil pan, flywheel, intake and exhaust manifold, engine mounts, timing cover, alternator, a/c and power steering pump. You already have a weber carb, which will swap over with the manifold, and the only other thing I might add is a Delta cams performance regrind camshaft.

The only other things to do get more expensive, with only small power gains. these would be a port and polish, lighten the flywheel as much as possible, balance all the moving parts, and you could go with the max .040" over bore with flat top pistons if you can find them. And a custom built header would be nice too, because I do not think you can buy one off the shelf.

There is more that can be done, but it gets so costly that going to either the 4age or 4afe would be a far better choice since I do not think the older 8 valve 3a/4a configuration will reliably take the extra power. I feel I have pushed my 3ac past its reliability point and do not even have a weber on it. So I am going 4age. No more carburetor for me thank you.

[danzo]

Thanks for the info, I was talking about only the 4ac's to answer DLB's question. I just thought maybe there was another car that used the same manifolds/water pump/etc. I was reading over some of the old posts and saw that someone got a good deal from a club4ag.com member. They yank the 4ac's from their ae86s and slap in 4age's. I will look into contacting some of these people, but will not put a 4age into my T4; too much effort, and I'm just looking for a little more cheap power.

[Petros]

The RWD ae86 that uses the 4ac would be a direct swap, almost identical engines as the Tercel as far as I know, but these are not as common as the transverse installation on the fwd corolla with the 4ac. you will likely still have to swap the pan and flywheel, so all you save is swapping out the intake/exhaust manifold and water pump housing/heater lines.

[PrescottAZ]

Would our stock head go on a 7a motor? Cause that might be a good option as long as there isn't anything funky. A 7afe is Very common.
Sounds like a lot of messing around to go from 1.5 to 1.6 when 1.8 could be an option.

I plan to put a 7afe in mine when I get a chance.

[toughtercel]

HEY 3a plus 4a equal 7A

[Petros]

You could likely adapt a 7a to fit the 3a head on it, give you more cc's and a much longer stroke (more torque), but there will be some messing with the oil pan, and finding a timing belt the right length. Would be much better to try and find a carb set-up that fits the 7a head and make it fit in the TErcel, but its a much bigger job. The 8-valve 3a head is obsolete, breaths very poorly, does not cool evenly and is not well suited for tweaking to improve power output, much better to use one of the 16-valve heads. There is someone on the internet that has a blog about building a 7age, putting a 4age head on a 7a short block, great project! It uses a Porsche timing belt to get the right length.