Spoilt for engine choice! (4afe vs 4age vs 7afe vs 7age frankenmotor)

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drafting3d
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Spoilt for engine choice! (4afe vs 4age vs 7afe vs 7age frankenmotor)

Post by drafting3d »

Hi all,
Recently I have aquired a semi-tidy 85 SR5 tercel, it is light green, as seen in some of the japanese brochures.
(SR5 with no aircon or power steer...)
It has a rather tired 3A
I have over 20 years of car tinkering, built a few fun toys
For most of that time Ive been keen on doing a 4age build in a fun car. I have had 5x early front wheel drive corollas (Ae82 with the 4AC)
So much fun.

So here is the conundrum.
I have access to:
FREE 4ac still in AE82 (was given to me due to headgasket)
CHEAP 4afe (they are very readily available here in Aus, for a few hundred from wrecker or even entire vehicle for $500 aud)
Early type 7afe 'wavy' rocker cover type, quite readily able to get. (1996-98)
later type 7afe with the straight and newer looking rocker cover (around year 1999 to 2001)
AAAND recently offered a 4age bigport 3 rib - needs 'bearings and rings' (from an Ae82, around 1985) TVIS and everything, includes flywheel.

I originally intended on refreshing the 4ac and having a nice weekend conversion process, add a weber and cam and exhaust etc. Easy done.
Then thought of a 4afe, as it has more potential than a hot 4ac, and Ive had a few (Ae95r 'all-trac' wagon) and they can take a proper beating.
THEN the 7afe argument, sure the deck is taller etc, but the extra torque and ALSO year 2000 engine appears to be a great combination for the little terc. Less gear changes too, can lug about without downshifting for the slightest incline.

Finally, brain farts....
7age frankenmotor. (late 7a block with the bigport twinky head) all the cubes, the easy to get parts. aaaand also the access to ITB's or bike carbs etc.

End goal isnt a drag/race/drifter, just need to be able to maintain 110km/h up hills with a boot load of adventure gear. (and not blow the gearbox)
I would be happy with 130HP final wheel power.
No need for smog compliance, as the terc is exempt here. so no ned for Cat or emissions. Still need to maintain a bit of retro cooless though.
I do alot of fly fishing up in the 4000ft altitude region (1300m) and live at sea level, AND 30degC in summer, 5degC winter

Im ok with spending some cash on it over the next 6-8 months to build the right combo, dont mind piston upgrades or cam upgrades either
I can run factory ECUs or aftermarket, likely something that includes O2 sensor and control for self learning.

Please help me see some logic, realistic power/torque figures.
Am I dreaming?

Help me obiwan kenobi, your my only hope
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Kozuto_98
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Re: Spoilt for engine choice! (4afe vs 4age vs 7afe vs 7age frankenmotor)

Post by Kozuto_98 »

The 4A-C swap would be the easiest to pull off. From what I understand it is a little easier on gas and has roughly 20hp (crank measured) over
the 3A-C. Should be a near bolt in swap.

If you go full on 4A-GE you'd need to check if the crank will take a 6 or 8 bolt flywheel. I know some early 4A-GE motors were 6 bolt.
I'm pretty sure the 3A-C crank will swap into a 4A-GE due to both motors sharing the same stroke length, and 4A-C cranks will for sure
work in the 4A-GE. There may be some concern with strength on those cranks but near stock power should be fine.

the 7A-FE and 4A-FE are fairly straight forward if you don't mind cutting into the firewall to keep the factory distributor location, and
if you want to run an ITB setup SMR2U sells a kit for both motors.

If you want to go aftermarket, the Speeduino platform seems really interesting. I've been doing a lot of reading into it as that's the
ecu I will be using with the 4A-FE swap I'm working on. Megasquirt, Link, or even Haltech are good options too but are a bit more pricy.
With the Speeduino ecu you'd have to run a separate lambda O2 sensor controller. Innovative has a really good kit for that.

Seeing a 7A-GE build in one of these Tercels would be really cool, can't wait to see what you do!
1987 Tercel Wagon SR5 4WD
1997 Acura CL
RIP 2016 Civic (wrist pin recall)
drafting3d
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Re: Spoilt for engine choice! (4afe vs 4age vs 7afe vs 7age frankenmotor)

Post by drafting3d »

Im leaning towards 7afe primarily due to the LACK of opportunity to spend $5000 on parts. The 4age is a money pit, lots of fun, but after adding up all the items needed, it really will cost a hell of alot more than the entire vehicle will ever be worth.
7afe with ITB's and Haltech (here in Aus, they can tune/log/firmware etc via wifi to their head office, so almost unlimited support)
Plus can incorporate torque limiting gear shifts too!
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Kozuto_98
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Re: Spoilt for engine choice! (4afe vs 4age vs 7afe vs 7age frankenmotor)

Post by Kozuto_98 »

7A-FE with a Haltech setup would be awesome to see.
I'd assume there is already a decent base map for the motor since it was also used in the Celica, plus some have done turbo stuff with it.

A couple years ago SirFoxx did a 7A-FE swap to a 1st gen Tercel, his motor was also modified a bit.
viewtopic.php?f=6&t=14830&p=109729&hilit=7afe#p109729
That thread might be worth a read for some info.
1987 Tercel Wagon SR5 4WD
1997 Acura CL
RIP 2016 Civic (wrist pin recall)
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Petros
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Re: Spoilt for engine choice! (4afe vs 4age vs 7afe vs 7age frankenmotor)

Post by Petros »

welp, all of those options can be done, and have been done before. all but the 4ac are a lot of work and costs, fabbing special parts, etc. to make work in the Tercel. I do not know how much trouble the taller 7afe would be to make fit under the hood, but certainly more effort than the 4afe, which would be my choice. the 4 or 7afe have excellent reliability and almost ideal torque curves for the Tercel4wd, personally I would go for the 4afe because less trouble to mount and fit and likely you would get better fuel economy as well, since it would also be my daily driver. you would still need to fab a custom exhaust header, and either relocate or convert to distributorless ignition to save cutting into the firewall, and have to do an EFI conversion.

The 7age seems to me like just too much work (and cost) to sort out a frankenengine to use as a daily driver. a 4age not quite as bad, but you still have the EFI, and header to fabricate, plus find a solution to the 8 bolt flywheel mounting. one benefit of the 4age is you can get adjustable cam gears and fine tune the torque curve so the engine has more power in the lower rpm range, and improve fuel econmy over the high rpm stock cams. but the 4 and 7afe does not really need the power curve to be lowered, it already has good power at low rpm.

I guess the question for you is, what are your goals for this car? what is it you hope to accomplish with the engine swap? that might help make your decision. Getting a lot more power into a tercel means you risk damage or premature wear to the drivetrain and also extensive suspension mods so it can handle the extra power.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
drafting3d
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Re: Spoilt for engine choice! (4afe vs 4age vs 7afe vs 7age frankenmotor)

Post by drafting3d »

end goal is a:
dirt capable daily
all terrain tyres on 15" alloys
rubber/poly mud flaps
additional underbody protection (sheet alloy, easy to fab and has some 'give')
mini tube bar front (wildlife strike prevention and fog lights)
LED spot lights
rear LSD
brake upgrade (Paseo/Echo/Yaris)
seat rail mod (6'4") or mod steering column for more knee room


gravel roads that have marbles on the outside edge. loss of traction is common, so is power slides out of corner. (not a drift, more of a rally exit)
Plus lugging a boot load of camp/fishing gear (or the odd chainsaw)
previously I had a highly modified KZN130 Toyota Hilux Surf that was VERY heavy and way too much fuel and maintenance

it seems a hot 4a is less work, more fun and tinkering keeps me happy.
I like the idea of the Holley Sniper 2bbl EFI setup (I would go full-nerd on it and re-tune it and not rely on the self learn)
Simple recipe seems: Lightening the flywheel, upgrade camshaft, 32/36 weber, and port matching, 2" exhaust

Camshaft selection here in Aus is non-existent. Need a solid source.

I just dont want to spend a few grand on a hot 4ac when the same amount spent on a 4afe (or even 4afc) would gain more with the cross flow head
THEN also dont want to be leaning on the 4ac too hard and pop it, only to re-do it all again! The TINY radiator looks half size!
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Re: Spoilt for engine choice! (4afe vs 4age vs 7afe vs 7age frankenmotor)

Post by Petros »

I do not know how you are going to get a rear LSD for the rear axle unless you up grade to a larger rear diff/housing. there are those inexpensive kits to covert an open diff to a sort of LSD, those look interesting and I may try one on my 4age swap Tercel some day. but they do not get a lot of positive reviews, perhaps in copared to a full LSD they are not as good, but I should think certainly they are better than the stock open diff. it might be possible to get a small LSD to fit in the third member with some machining and cutting/welding, but that also seems like a costly way to go.

the 4ac is a straight forward and easy swap, no having to fabricate special parts. everything is bolt on, power is limited to perhaps 85-88 hp (mostly I think limted by the 8 valve head design). I am running one on my daily driver and happy with it, but it is not a power house. if feels about the way the car should have been when it came from the factory, but does have decent torque for pulling up long grades.

the 4afe will also get you great torque and good economy, good reliability, and about 100 hp (perhaps a bit more with a few tweaks like higher compression, clean up the ports and a good exhaust system). relatively inexpensive, but you will have to relocate the distributor or go to a distributorless ignition. I would go with a factory ECU, since that should be cheapest if you can pull one from a wrecking yard. you would also have to figure out the re-wiring of the engine bay and a high pressure fuel supply system.

the 4age in stock form can work and give you 112 to 130 plus hp (depending on how much you want to spend on it). I would keep the stock cams and add adjustable cam sprockets to de-tune it to improve low end power (which are my plans for my swap project). you will also have to build an exhaust system and a high pressure fuel supply, rig the wiring and figure out how to make the tercel flywheel work on it. there are a few alternatives. but the distributor can stay where it is, and all of the hard points bolt up (engine mounts, bell housing, etc.).

it is a tough decision, each has advantages and disadvantages. I choose the 4age because of the factory distributor location, but both the exhaust system and the flywheel fitment can add a lot of cost if you do not have access to a shop to make it work. I also wanted the EFI because it is very reliable, almost maintenance free compared to a carb, and offers better economy AND more power output over a carburetor. And if I want more power, there are lots of options for this engine.

Good luck.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
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Kozuto_98
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Re: Spoilt for engine choice! (4afe vs 4age vs 7afe vs 7age frankenmotor)

Post by Kozuto_98 »

The AE86 LSD is a good option for these if you can find one. These Tercels share the same rear axle as the AE85/86.
That's what my Tercel has for a rear end as it was given to me as a gift from a friend when she parted out her AE86. Be warned though, using
4WD with an LSD in these on dry roads may bind the transmission or axle. It probably doesn't help that the rear end needs an overhaul.
Certainly makes for a good time in the snow though!
1987 Tercel Wagon SR5 4WD
1997 Acura CL
RIP 2016 Civic (wrist pin recall)
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Petros
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Re: Spoilt for engine choice! (4afe vs 4age vs 7afe vs 7age frankenmotor)

Post by Petros »

Kozuto_98 wrote: Fri Feb 19, 2021 7:27 pm The AE86 LSD is a good option for these if you can find one. These Tercels share the same rear axle as the AE85/86.
the Tercel4wd rear axle is the same as the earlier RWD corolla, and similar to the AE86, but they are not the same. they appear to mount the same (I measured them side by side), they are the same width. But the Tercel4wd diff is 6" dia as I recall, and the AE86 (or at least the LSD from the GTS corolla) is 6.5" dia, and has a larger third member and input flange. so you would have to swap out the whole axle assembly, figure out a way to make the rear disk brakes work on the Tercel4wd (and either run different wheels front to rear, or covert the rear flanges somehow to 100mmx4 bolt pattern). and than get a larger corolla driveshaft aft U-joint and flange, and have a drive shaft shop splice that into the aft end of a Tercel4wd driveshaft (and reblance it). so it can be done, but it is not an easy, nor inexpensive swap over. the the last time I ran across someone parting out a GTS AE86, they wanted as much for the rear axle with the LSD as the whole car was worth.

it would be nice if there was a small LDS diff that can be adapted to the stock third member of the TErcel4wd. they make a small LSD for the mazda miata, but it would likely take some machining to get the dimensions all correct to fit in the Toyota Tercel4wd diff assembly. you can also weld it up solid, but that would make it unsuited for daily driving on the street. and there is that conversion kit that does not look too bad to adapt, but it does not function as good a true LSD. with all that spare time I do not know what to do with ( :lol: ) I might try and make that fit in a spare rear diff assembly I have and see how it works.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
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Kozuto_98
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Re: Spoilt for engine choice! (4afe vs 4age vs 7afe vs 7age frankenmotor)

Post by Kozuto_98 »

Did the first gen Celicas come with a factory LSD?
I vaguely remember hearing about people using that axle in the AE85/86, and or vice versa. Might be something to look into.
1987 Tercel Wagon SR5 4WD
1997 Acura CL
RIP 2016 Civic (wrist pin recall)
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AugustusFerdinand
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Re: Spoilt for engine choice! (4afe vs 4age vs 7afe vs 7age frankenmotor)

Post by AugustusFerdinand »

drafting3d wrote: Wed Feb 17, 2021 2:02 pm 7age frankenmotor. (late 7a block with the bigport twinky head) all the cubes, the easy to get parts. aaaand also the access to ITB's or bike carbs etc.

I would be happy with 130HP final wheel power.

Im ok with spending some cash on it over the next 6-8 months to build the right combo, dont mind piston upgrades or cam upgrades either
I can run factory ECUs or aftermarket, likely something that includes O2 sensor and control for self learning.

Please help me see some logic, realistic power/torque figures.
4AC is the obvious easy swap and has been done many times here.

4AFE and 7AFE are going to require you to go with a distributor-less ignition or cut a hole in the firewall. The latter being more difficult than just changing over to distributor-less. The 7AFE is going to have the same hood clearance issues as the 7AGE mentioned below. However even a fully "built" 7AFE (cams, porting, decked, high compression, etc) is going to barely get you 130whp, I wouldn't expect anything even close with a built 4AFE.

4AGE will have better hood clearance (likely just need small crossmember spacers) and while it won't have as much torque as the 7AGE, you'll be able to hit 130whp just as easily with the standard bolt ons. You'll need to either have the 4AGE flywheel turned down to fit the 3AC's ring gear or have the 3AC's flywheel redrilled for the 8 bolt crank on the 4AGE. Both have been done here as well.

7AGE with smallport pistons will get you 11:1 compression and an easy 130whp with no other mods necessary. You can run it on a stock ECU, just need to run larger injectors to account for the higher displacement or an adjustable fuel pressure regulator with higher pressure to spit out more fuel. Or as others have said, and I am doing, run a standalone like Megasquirt or Speeduino.

Now with the 7AGE there's a lot of mixing and matching parts, but nothing that's all that complicated. What you do have to deal with is knowing that the engine alone, without the stock intake manifold, will sit a few inches above the hood line. So you need to decide how you're going to deal with that, add a couple more if running a stock intake manifold.

I'm doing a 7AGE build, but if I'm honest and was in your position with what I know now, I'd probably just go with the 4AGE. It'll be the high revving motor the 3AC wishes it could be, it'll make plenty of power with very little effort, and even though it'll have less torque than the 7AGE, the weakest stock 16V 4AGE has more torque than the 3AC could dream of making.
1983 Toyota Tercel SR5 - 7AGE swap in progress
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