Engine Swap options

[SynthDesign]

Regarding the 7A-FE
One thing to consider thou. When was the last time you heard about someone bragging about their 7A-FE. Not exactly a "Formula Atlantic Motor" I get enough shit from the guys at Toyota and in the other forums about being this hard-core about T4WDs. There just doesn't seem to be that much following. That could mean a cheap motor thou. A bit of after marker support.
I had a Preo Gism that had a 7A-FE. I could never get the oil pans to seal properly. I took it Toyota after attempting it twice and they couldn't get it to seal either.
Biggest positive was the reliability of the head. Never had to adjust the valves or have the head resurface or any warp-age what-so-ever. I put over 200k on it and sold it for what I paid w 327K miles.

Only a FWD platform right...? Was it ever used in a RWD or ALL-wheel drive configuration? Does it use a pilot bearing at the end of the crank(our trani 's really need them)? Just curious.

Also...

There's a guy up in Milton WA that I've been trying to get a hold of. He put a T4WD chassis on an 85 4x4 Toyota PU w/straight axles frame running a 22R-ET. I REALLY wanna see it.
So that's a bit more than a motor swap though.

[Typrus]

Quite a few AWD Setups even use the transverse engine position.

The short-frame gen 1 4Runner frame would fit quite nicely under a Terc based on my examining both design measurement graphs. Throw in a supercharged 5VZ-FE. Rawr. lol.

The advantage of the 7AFE is torque low down. The advantage of the 4AGE is high revving HP. And very large aftermarket support.

[takza]

Boy - ALL of you guys know how to make a feller feel dense and out of your league!
Wow!
Tom M.

All them letters and numbers don't impress me none either! Gol-danged codetalkers....

[Petros]

The 7AFE is an enlarged and longer stroke 4AFE. I think the heads are identical (or almost so), it was built for low speed economy, specifically as a good gas mileage engine. There are some that have put the 4AGE head on it and made a high powered hybrid called a "7AGE" which was never produced. Apparently the "7AGE" will bolt into any car that had the 4age or 4afe in it.

because of the longer stroke (longer crank swing) it has a lot more torque at lower RPM, and in fact the torque curve for it is almost flat from 2000 rpms up to about 5000 rpms, staying between 110 to 115 ft-lbs. The 4afe torque curve is almost the same shape, but lower, about 90 to 95ft-lbs. This means it should pull real strong from as low as 1500 rpms and up.

[gatemaster]

According to wikipedia the 4af produced 96 hp (67 kW) at 6000 rpm and 95 ft·lbf (128 N·m) at 3600 rpm
The 4afe produced 105 hp (77 kW) @ 5800 rpm 101 ft·lbf (137 N·m) @ 4800 rpm
The 7afe produced 115 hp (86 kW) at 5600 rpm and 115 ft·lbf (155 N·m) at 2800 rpm

As you can see the longer stroke of the 7afe is what brings the peak torque down to 2800 RPM

So for our cars the best possible combo is a 7afe short block with a small port 4age head if it will fit.

The 4afe or 7afe head has the problems of: slave cam drive, poor dizzy location, poorly shaped ports in the earlier versions, a slow burning combustion chamber with heavily shrouded valves, less aggressive camshaft profiles, ports of a small cross sectional area, a very restrictive intake manifold with long runners joined to a small displacement plenum.

[Petros]

What you do not see with that is the torque curve is almost flat for both 4afe and 7afe engines, I think the 7afe still is about 110 at 5,000 rpms. ANY of those engines, even with the poor head and intake manifold designs, would be a big improvement in power and performance over the pathetic 62 hp 75 ft-lb stock 3a engine.

[terceldude]

Again, the 4A-ELU:

http://pensacola.craigslist.org/pts/905940364.html

As for the specs, using Babelfish, I got:
The engine which adopts the thin combustion control system by worldwide first [rinmikusuchiyasensa]. The Toyota kalium which is sold in 1984 May - it loads onto the [na] FF4 door sedan. It equips [rinmikusuchiyasensa], in exhaust type, it detects the air fuel ratio the side which is thinner than theoretical air fuel ratio. The fuel oil consumption actualizing the air fuel ratio feedback in a thin state where the computer controls precisely with this detection signal. In order to be able to obtain optimum combustion, ignitability while program independence injecting and the lean mixture which each cylinder independently change injection quantitative injection timing precisely adopting the platinum plug and the advanced igniter which improve. In addition, even with the lean mixture of air fuel ratio 23 or more it makes stability combustion possible with the improvement of engine itself such as swirl control valve, the 1600cc class top fuel economy 17.0km/l (10 [mo] - [do]) actualizes low. Location: The Toyota Motor Corporation corporation (〒471-8571 Aichi prefecture Toyota city Toyota Cho 1 addresses) Production (production) year: 1984 Production person (corporation): The Toyota Motor Corporation industrial corporation Type of data: Mass production item Present condition: Retention secret Type/production Type: 4AELU engine Company name: The Toyota Motor Corporation corporation Use: Engine Production year: 1984 Statistics Arrangement of cylinders number: Serial 4 cylinders (4A-ELU) Cycle/cooling system: /Water cooling Valve type/number: OHC/ Total cubic displacement: 1587cc Inside diameter × distance: 81.0×77.0mm Compression ratio: 9.3 Ignition system: Full transistor system Efficiency Installed capacity: 100PS/5600rpm Largest torque: 14.0kgm/4000rpm Device Supercharger type: It is not Feature: As the thin combustion control system by [rinmikusuchiyasensa] the worldwide beginning In addition item: Carburetor: EFI; Fuel injection: It is; Exhaust purification: Oxidation catalyst device; Variable system: SCV; 240 selection tops > gasoline natural gas engine > 4AELU engine ([toyotakarina] FF4 door sedan loading)

Original data is at this link:
http://www.jsae.or.jp/autotech/data/9-12.html

[gatemaster]

1

[Petros]

That 4AELU is the 4a engine with an almost identical 8-valve head as our 3a engines, it is for a transverse installation for a JDM car and is fuel injected. I would not bother with it, I want to get rid of the 8-valve head. The only advantage, besides the EFI, is the exhaust is on the same side as our existing engine installation. I would not put a turbo on a 3a engine, you will have the same head issues as I have with a high compression 3a, burnt valves and blown head gaskets. that is why I want to switch. I would not want a turbo for a daily driver anyway.

For comparison I searched and found this image of a stock 3age power curve (though in a different format than above), it is wheel hp and the stock engine is in blue. the red line is with a performance cam installed without any other mods. It is interesting how flat the torque cure is for this engine (compare with the above 4afe and 7afe curves) but it does not rise until about 4800 rpms. I have seen other power curves for the 20-valve turbo version where the torque comes up much lower at around 3000 rpms. Looks like the 7afe wins out again.

[gatemaster]

I

[Typrus]

I wonder if the amount of metal removed from the head is part of the problem? Reduced resistance to torsion? But it did reduce hot-spots. Hmmmm.... If one were to stick with a SOHC, I'd say a 4AE might be good. Dizzy is in the right place after all. Just looks like the intake might be an issue. Injectors in head or in manifold?


74ft/lb isn't that much less than 95.... The better torque curve however would be something to seek.

Twin-charge baby!!!

[terceldude]

That 4AELU is the 4a engine with an almost identical 8-valve head as our 3a engines, it is for a transverse installation for a JDM car and is fuel injected. I would not bother with it, I want to get rid of the 8-valve head. The only advantage, besides the EFI, is the exhaust is on the same side as our existing engine installation. I would not put a turbo on a 3a engine, you will have the same head issues as I have with a high compression 3a, burnt valves and blown head gaskets. that is why I want to switch. I would not want a turbo for a daily driver anyway.

For comparison I searched and found this image of a stock 3age power curve (though in a different format than above), it is wheel hp and the stock engine is in blue. the red line is with a performance cam installed without any other mods. It is interesting how flat the torque cure is for this engine (compare with the above 4afe and 7afe curves) but it does not rise until about 4800 rpms. I have seen other power curves for the 20-valve turbo version where the torque comes up much lower at around 3000 rpms. Looks like the 7afe wins out again.

Possibly, but usually that stuff would occur if you didn't lower the compression for the turbo. Did you see the pic from the My Car Enjoy Manual, that I posted? It was successfully turboed with the HKS HT10 unit... Don't know how much boost but certainly enough to really make it go VROOM, VROOM, VROOM, lol. I still plan on using the 3a engine or 4a, per say, for the turbo and not being a sissy about engine swaps that other people would do. Meaning, I will try to see what more power I can get out of the 3a/4a, turboed with headers on it, Schneider cam, custom crank, ROSS and PAUTER racing internals, etc... I know the little sucker can put out a lot!!!! I don't need a stupid 4AGE....

[terceldude]

Thanks for the 3AGE torque curves, though. That might help....

[gatemaster]

I wonder if the amount of metal removed from the head is part of the problem?

In my case the head wasn't milled. The machine shop checked it and said it was straight.

I will try to see what more power I can get out of the 3a/4a, turboed with headers on it, Schneider cam, custom crank, ROSS and PAUTER racing internals, etc... I know the little sucker can put out a lot!!!! I don't need a stupid 4AGE....

I felt the same way for awhile but at some point unless you have lots of money to spend its not worth seeing what it could do. I think the bottom end of the 3ac is strong enough but does not have enough stroke. A stroker crank is the only reason for changing it and even then I would go with a welded up and turned down crank, if there is room for a stroke increase. But that would require custom pistons to deal with deck height. The 4age is not stupid, what is stupid is the lousy design of the 8 valve head. the 3ac block is fine, it is the head that sucks. If you want to see what it can do, then see what the racers are getting out of it.

[Typrus]

Want to see what it can do?
Go buy a 4AGE 7-rib block. What? Its just an overbored 3AC with a lot more strength and if you can find it, oil cooler jets!
Throw expensive, awesome bottom end componants in it. Billet goodies. Non-twist forgings. Do it to it! Get the best balance job you can. Within a gram or less.
Now, get your 3AC head cleaned up. Minimal metal removal if possible. Get the runners about equal, gasket match if you feel the need.

Now, custom intake and exhaust manifold.

Schenider 300F camshaft (or the high duration turbo grind if you go turbo)
Check for clearance with the 4AGE relieved pistons.

Paradise valve springs and the likes.

Get your rocker assembly cryo'd. Maybe see about getting needle-rollers put in the rockers to cut shear loss on the shaft.

Use ARP studs for the head and tighten well.

Did you remember to use a good head gasket?

Now, go for it. Weber 32/36 (it flows a lot remember. Just jet it differently than a stock 3AC or 4AC) or maybe some sidedrafts. Or go for a custom stand-alone EFI system.


Break it in appropriately. Now, see what kind of power you have from 4000 to 8000 RPM. It'll be absolutely awesome compared to stock, and you might even give a stock 4AGE a run for its money.

But, as everyone does, you'll ge tthe "more power" bug.
So what now?

Take off the SOHC, throw on the 4AGE head you have sitting in the shop from the block you bought. Maybe get it ported out. Heck, just get it ported and cleaned up. Nothing else. Now, watch as you spank all the speed records you had from the super-3AC. With a very similar powerband.

There. Miminal money spent on the top end, and you already have a sweet 4AGE bottom end.


Now, go offroading and kill it at every hill. OR roast the clutch and maybe tranny. lol

The 7AFE is a bit taller. How much so? If a K740 Weber kit can't have the standard air filter and fit under the hood, will a 7AFE fit?
Even if you put the 4AGE head on, the stroke will tend to yank the powerband down a bit. More torque, lower down.

Or, if you want to go RWD setup, go get a JDM 3S engine coupled to a RWD tranny (they exist) and create a monster that way. The 3S, GE in particular, has a HUGE aftermarket following, and is a sweet 2.0L. If you really wanted to, go find a 5SFE block, throw a 3SGE head on it (theres a place in Texas that specializes in this- go search toyotanation.com) and have yourself a strokey 2.2L "G" series. 500hp+ isn't unheard of. Rawr.