Horrible page in the tech section

yoshimitsuspeed
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Horrible page in the tech section

Postby yoshimitsuspeed » Sat Dec 13, 2014 11:27 pm

Someone just posted a link to this page and I couldn't believe the misinformation there as well as not terribly accurate opinions.

http://club4ag.com/faq_and_tech_pages/P ... 04A-GE.htm

Realistically I would just delete the whole top section.

There are serious debates as to which 4A-GE to use on your car. Some say late 16V from a 89-90 AE92, others say the 4A-GZE, the 20V, etc... The truth is that all 4A-GE has characteristics that are of merit and there are many things to look at. The bottom line is that you should choose an engine that best fits your needs and budget. I've seen too many projects that ended up as too expensive, incomplete, or just not what were the original intent. So I've put together a small list of things pertaining to what one might want in the 4A-GE and some of the merits and demerits to the choice of the 4A-GE.

Before I do go on, you must note the following... the ultimate power output of the engine actually has little to do with which version 4A-GE you choose. With enough modification and tuning, any of the 4A-GE can be tuned well past the 200 horsepower mark. This all just depends on how much you can modify for your specific use and who actually does the tuning. I have seen 4A-GZE modified with about $5000 that posted under 120hp on the bench and I have seen lightly tuned and well cleaned up 4A-GE 16V NA that posted over 150hp on the bench. Your selection of the intake peripherals, exhaust, computer unit, state of tune, internal customization all comes into play here... The following is only a guide to point out the best suited "base" engine, or starting point for your future direction of modification. In choosing any engine, be especially careful of the condition as most buyers of 4A-GE will get the engine "used" and internal condition can have a big difference on how much you will spend to recondition it or rebuild it later...


This is mostly irrelevant, and if it was kept could be worded much better and more concise.

The first edition 4A-GE, the ones that came in AW11 NA, AE86, AE92 (1988-89) can be distinguished primarily by the head design. It was the only version that utilized the TVIS system which opened and closed the secondary runners depending on driving conditions. Some refer to them as "blue hat" due to the blue lettering that were used on the valve covers. However, this designation isn't entirely accurate as early AE92 with TVIS had red letters as well as some other models that used this engine.


This is the second generation of the 4AGE.
I feel like we should stress not using top colors to try to get new members away from the confusion it raises. This page is a perfect example. The second generation 4AGE came with red and black lettering. The third generation came with red lettering. This is usually where the confusion comes in. Half the world thinks the gen 2 is the red top and the other half thinks the gen 3 is the red top. We need to dissuade using top color as terminology on the 16v.
Never in the 10+ years on these boards have I heard it called a blue hat but that's neither here nor there.

These are frequently mistaken for the later generation engines which also used the "red hat" valve covers. These covers are also interchangeable so it's hardly a way to distinguish these motors that are worked on so much... The early 8-port TVIS engines are still in demand today for low budget tuning for those who enjoy reaching high rpms with the use of carburetors. Though the connecting rods journals and pins are smaller than the later models, the components are lighter than the latter motors and in stock form, tends to feel better at the top. The TVIS when operated properly (factory ECU or via external controllers) can add great deal of drivability in low and mid ranges of the rpm and is effective for using high profile cams and keeping it still streetable. It still is the heart and soul for many AE86 and AW11 owners, and is by no means a bad engine if engine feel is your pleasure. A nicely balanced and ported TVIS head can be had for cheaper than any other head with very good results for use on normally aspirated use.


Again the poster almost tries to address the top color confusion but once again ruins it completely.

As far as the US and most other markets are concerned this covers it pretty well although there are oddballs and variants
Gen1 Largeport 3 rib
Gen2 Largeport 7 rib
Gen 3 Smallport
Gen 4 Silvertop
Gen 5 Blacktop

The GZE had a largeport and smallport variant and internally were essentially identical to their NA counterpart aside from the pistons.

Everything in that section is wrong. The gen 1 is the only gen that had lighter internals. More technically the 18/40 rotating assembly.
Everything after that had the bigger 20/42 rotating assembly.

This is not 1987 from a performance point of view there is no good reason to run carbs.

The second generation 4A-GE was introduced in the AE92 in 1989 to 1990 models. It featured a stronger internals via larger diameter pins at piston as rod as well as more re-enforced block assembly. The pistons featured higher compression rating giving slightly more torque and peak power output. This is the main reason most users swap this engine in place of the first generation 4A-GE. This engine also featured larger injector sizing with spray patterns differing with the first edition. TVIS was removed as compression rating was upped to give almost as much torque below as the TVIS model with lower compression. Still, many drivers will notice some decrease in response with this second model 4A-GE as internals were heavier and the absence of TVIS made low end performance sluggish to the feel especially when the peak power seemed to improve enough.


This describes the third generation 4AGE
Same internals as the second generation.

The newly worked internals of the 2nd generation engines also served as the basis for a new type of 4A-GE, the 4A-GZE. The supercharged cousin of the 2nd generation 4A-GE produced a whopping 21kg/cm of torque at relatively low 4500rpm. This engine was said to be designed to give the AW11 MR2 unprecedented power of 145ps JIS. And eventually, a slightly modified one was fitted to the AE92 also. In 1990, the 4A-GZE was reworked to 170hp rating due mainly to higher compression pistons (still much lower than an NA) from 8.0 to 8.9, and higher boost, via smaller supercharger pulley and newly designed electromagnetic clutch. This is another popular swap for normally aspirated cars wanting flexible street performance.

There was a gen 2 GZE and a gen 3 GZE as well as smaller variants such as USDM AFM more reknowned for the low end leanout over 8 PSI, the JDM AFM ECU that at least some did not and then a MAP variant and finally a MAP variant with DLI.
The Gen 2 as the NA was a largeport and the gen 3 was a smallport.
Gen 2 is 8.1:1 compression
Submitting now because I haven't saved in a while. I will continue in an edit.


The biggest change in 4A-GE was made with the introduction of the AE101 Corolla. The new 4A-GE engine was designed to be normally aspirated only from the outset and as such featured exciting new parts as individual throttle and variable cam timing, the VVT. The main distinguishing feature of this new 4A-GE is the 5 valves per cylinder design. The use of a completely new head provided 4A-GE with power to almost compete with Honda's popular VTEC B16 engines. Aside from the obvious external peripherals, this 20 valve engine was delivered with slightly improved internals with semi-coated pistons and balanced rods. The AE111 in 1995 was equipped with yet another improved 4A-GE, the same 20V was tweaked for more power delivery and response. Internally, the the compression was again raised to 11.0 from 10.5 and rods, pistons were better balanced and much lighter. The throttle body was bored slightly and cam profiles and timing altered slightly. The first 20V engines had silver spark-plug covers and thus was coined "the silver-head" and latter "black-head" but again, the covers do interchange so it's not a reliable identification method. A good way is to take a look at the throttle body as later model engines sported a larger intake vanturi and more rounded intake tract.

So that's roughly the different 4A-GE's in a series...more detailed information can be had in specification chart posted elsewhere in this site.


This is mostly accurate but still not very well done.

Does any one have a source on the balanced rods? I have never heard this. The ST rods are nearly identical to the SP rods.
Any sources on the BT being better balanced?



First Generation 4A-GE (16V AE86/AE82/AE92 88-89/MR2 NA)

Pros

Inexpensive as used engines

TVIS

Parts availability in aftermarket and cost of upgrading is nominal

Equipped in most number of cars

Best fun per dollar

Spins better than later 16V models

Takes regular gas (low octane)

Good race track engine base

Durable

Cons

least powerful (unmodified) 9.4:1 compression

Not entirely suited for high output applications


Best fun for dollar? WTF does that mean?

Good race track engine base? Why? Smaller internals, non floating wrist pins, low compression, much less aftermarket support.


Second Generation 4A-GE (16V AE92 90-91)

Pros

Higher compression of 10.4:1

Stronger internals for heavy modifications

Easily swapped with early model 16V

Most aftermarket parts shared from first generation 16V

Simpler non TVIS design

Good autocross/ street / normal aspiration drag engine base

Durable

Cons

Lacking in supply, currently somewhat costly

Not a great deal of improvement from original 16V technically


Again this is the third gen.
Compression is generally referred to as 10.3:1
Same internals as second gen.

Most aftermarket parts shared from first generation 16V


Useless and not terribly true.

Durable isn't really correct. There are a ton of gen 1 motors with 250k miles on them.
The 7 rib blocks could be called stronger or more robust but they are all pretty damn durable.


4A-GZE (AW11 SC/ AE92SC/AE101SC)

Pros

Highest OEM overall torque output by far.

Ready for other forced induction / NOS modifications

Good street / drag engine

Tire smoking effect dramatic.

Based on the 16V

Durable for many modifications

Cons

Expensive to transplant

Erratic under heavy stress and heat

Excessive driveline and tire wear

Needs many peripherals specific to this engine

Tricky install and diagnose

Tricky to handle in autocross and small track

4A-GE's peaky singing character somewhat lost


Two different generations of GZE need to be addressed.

Torque output is irrelevant to acceleration until you apply RPM. Once you do that is called power. The GZE does have better low end power than stock NA 4AGEs.

Tire smoking? Useless opinion.

Based on the 16v? It is the 16v.

Expensive to transplant? Not really but you also don't gain anything impressive other than better pistons. I call it an expensive step sideways. Put forged pistons in an NA 7 rib and you are further ahead than a GZE swap.

Erratic under heavy stress and heat

WTF?

Excessive driveline and tire wear

What's excessive? With more power comes more driveline wear.

Tricky install and diagnose

Maybe if you are someone who knows nothing about the 4AGE and has no business posting their uneducated opinion about them.

Tricky to handle in autocross and small track

It's called throttle control. Not the motors fault.

4A-GE's peaky singing character somewhat lost

All 16 valves fall on their ass with stock cams. The SC12 makes it a little worse but not much.
Again more of a useless opinion.


4A-GE 20 Valve (AE101/AE111)

Pros

Great sounding from individual throttle

Advanced ECU

VVT makes individual throttle and high-cams drivable

Quad Throttle gives serious response

Peak rpm response unequalled

OEM form an excellent upgrade for older car application.

Best balance with AE86, though tricky and costly to install

AE101 version core engine inexpensive and abundant

Excellent race track /street /autocross engine

Best balanced internal components

Cons

Complex to modify

Expensive to modify

Not suited for drag racing as parts are expensive

Currently limited modification parts available for heavy tune.


Very distinctly two different generations.

VVT makes individual throttle and high-cams drivable

Poppycock
VVT gives a broader powerband. ITBs would be just as drivable without it. You can't even notice the VVT being on or off by the seat of the pants. It just helps broaden the power curve, improve idle and emissions.

Quad Throttle gives serious response

The one guy who would actually notice the improvement in throttle response by the seat of the pants.
Image
ITB throttle response is the kind of thing that shaves off milliseconds on the race track, not the kind of thing that has a big impact on driving and no noticeable difference in response. Want ITB throttle response then just give it the gas .02 seconds sooner in the corner.

Peak rpm response unequalled

OEM form an excellent upgrade for older car application.

Best balance with AE86, though tricky and costly to install


More opinions depending on a lot of other variables.
In many situations you can build a 16v to outperform a 20v for similar or even less money than a 20v swap.

Complex to modify


Not really

Expensive to modify

Sometimes. Really depends on the situation and goals.

Not suited for drag racing as parts are expensive


WTF?

Currently limited modification parts available for heavy tune.


Maybe this was written in 1995 when nothing was known about the 4AGE. I hope so.

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