1600 4AGE Twin Cam


This information is the best compilation of 4AGE I've seen. I hope you find this as valuable as I have. There is much more information on both the 2000 3SGE and 1600 4AGE at the site.


That site is maintained by Russell Turney.


I recommend you go here to further enrich the experience. I have only captured what I think will be relevant to my car.

Toyota 4AGE Engines
in Rear Wheel Drive Applications -
The Definitive Guide?


The original Toyota 4AGE 1587 cc 16 Valve DOHC EFI engine was first introduced in 1983. It has been produced in transverse FWD layout (Corollas, Sprinters etc), transverse RWD layout (MR2) and longitudinal RWD layout (RWD Corollas, Sprinters). This page deals with the modification of the 4AGE and derivatives to a North-South RWD configuration.

It is very much under ongoing construction and will be updated on a regular basis as further information comes to hand. There are not many pictures at present, but stay tuned.

I am a great believer in what Liam Venter calls 'Grin Factor' - which can also be described as 'Bang for Buck'. For this reason I prefer to do some research and shoehorn in a stock engine that already has the kind of performance I am after, rather than modify an engine to attain these outputs. For me that is the cheapest and most reliable option - which works for me as I do not seriously race my cars.

Accordingly there is not much information on this page about modifying engines for competition use - I just plain know nothing about it. If you do, and would like to add some light on this subject, please contact me.

Be warned that bolting a FWD 4AGE to a RWD gearbox and mounting the unit in a car is the easy part - the difficulty lies in getting the intake systems and radiator plumbing to fit. The 20 Valve motor poses even more problems, as the distributor is driven off the back of the exhaust cam and may need a firewall recess to fit (unless some radical modifications are done to the ignition system).

Engine Age

The engine can be aged with a fair degree of reliability from the printing on the spark plug leads. If these are missing, or you seek further confirmation, remove the topmost cam belt cover and examine the inside for the small roundel from the die used to mould the part, which will have the year and month of manufacture marked in it. As Toyota utilise a 'Just in Time' manufacturing system it is unlikely the engine is more than a few months older than these dates.

4AGE Models

The 4AGE has undergone several revisions and improvements since introduction, which have seen improvements in power output and reliability - not that the engine was poorly designed to start with. The engine has always been produced with EFI, and later models included an optional supercharger (4AGZE) or 20 Valve head with variable inlet cam timing (VVT). There is rumoured to be a supercharged 20 Valve, and a factory turbo 20 Valve motor, but I am unable to confirm this, however Toby Hunt, had this to say:

"I have actually seen a factory Turbo Corolla in Sydney - Queensland Japanese import. Looked like a AE 82 hatch (mod to late '80's) but was a two door, not four. Intercooler (interwarmer?) on top of the engine, funny sort of body kit. Lots of stupid Japanese stickers (twin-cam turbo etc) Also seen picture of motor sans car from South Aussie wrecker (15k on motor)"

So, is this a factory car, or else a high quality aftermarket install done in Japan? Anyone else seen one, or got photos?

I upgraded from a 1983 16 Valve 4AGE to a 1991 20 Valve in my Leitch Super Sprint (Lotus Seven Replica). Aside from not having driven the car for 6 months during the rebuild (I did a lot of other mods to the car), the 20 Valve felt smoother and quieter, but not necessarily more powerful, due to the extra refinement. Ron Scanlan has dyno'd a few of them, and says:

"The 20 Valve is a bit of a strange one for horsepower. They feel completely flat when driven but whenever I have put one on a dyno the HP is nearly always around 136 at the wheels'.


By all accounts if a cambelt fails on any 4AGE the valves still do not hit the pistons, however it is obviously wise to change the belt when you get the engine. Although the stock belt should last approximately 100,000 km, I have heard of failures at 40,000 km.

They are fairly cheap if you go to the right places - I got one for about 40% of the Toyota part. The 20 Valve belt is 2 teeth longer than the 16 Valve belt - when I got one from a general auto parts shop they said that belt was listed as 'Lada Samara'!

Some people who race prefer to run without the cam belt cover, on the basis that the belt will run cooler, and is readily visible for wear. The top two covers should be removed, however the bottom one remains in place to leave the timing marks visible. It is advisable to cut away the lower portion of the bottom cover to allow gunk (technical term!) to pass through and not build up. By all accounts an additional bonus is the more audible belt whine, that sounds similar to a blower drive, which may be useful in psyching out other racers!


If the motor is going to be used in unmodified form, then I would suggest you go no further than removing the cam covers and inspecting the top of the head, and removing the sump and checking a couple of bearings. If these are OK I would not bother stripping the engine down for a rebuild until it starts to misbehave. Unless they have been abused they are inherently very reliable.

Some FWD motors involved in heavy collisions can apparently suffer from a cracked block in the vicinity of the engine mounts.

RWD Installation

The RWD 4AGE as fitted to the AE 86 model Corollas is the easiest option for use in RWD cars, however the engine is only 88 kW, and they are all getting pretty old now. Any 4AGE can be modified for RWD use, however the complexity of the installation varies depending on the type of car.

Oil and Sumps

Most RWD installations mount the engine upright as opposed to the slight angle it sits on in the FWD set up. This does not effect the oil delivery, however the majority of people installing the engines into Lotus Seven type sports cars also shorten the sump. They tend to chop the sump off level at the 'high' side, which takes about 30 mm out the 'low side'. Provided the oil pickup is modified in the same manner there are generally no problems. I run my engine about 5mm above the 'full' mark on the dipstick - and in 75,000 km have not had any problems. Fitting a 3mm steel 'bash cap' to the bottom and front of the sump is wise in low cars. Toby Hunt again:

"PRB (an Australian Lotus seven-type kit car manufacturer) casts an alloy, baffled sump for his cars (Aus $300) wider, but not as deep as factory one - very high quality. Probably easier to buy one than to mod stock one. Saw a PRB clubman with full race motor (dry sumped) Interesting problem. With modified steel sump, motor ran fine (210hp) After a alloy dry sump was fitted, broke 3 cranks in a season. Apparently alloy sump is very rigid and stops the block flexing at high rpm (funny resonate frequencies in the crank perhaps)"

The 1987 onwards engines have oil cooled pistons via little jets aimed up the bores. These engines also have a higher capacity oil pump to make up for the increased demand.

Some 4AGEs come with a factory oil cooler. This seems to be a pressure bypass type, with the oil being cooled diverted from the engine oil system to the oil cooler and then returning directly to the sump via an external fitting. This is a contrast to aftermarket sandwich plates that are either thermostatic bypass or full flow, and divert oil from the oil filter to the oil cooler prior to going through the engine.

Some Japanese AE 86 cars have the factory sandwich plates, as do 1988-1991 US Toyota Corolla GT-S. To use the factory set up on another car, you need the oil pan/sump (unless you modify one to take a return fitting), the sandwich plate that bolts on between the oil filter and block, and the cooler core. Some MR2s have an oil cooler also, however it uses radiator water for cooling via an in-line heat exchanger as opposed to a radiator. The sandwich plates are identical.

Running an aftermarket thermostatic sandwich plate oil cooler in my 20 Valve Lotus Seven Replica reduced my radiator water temperature by on the gauge, ie previously the gauge sat at , and now it sits on . If you are going to be giving the motor a hard time do yourself a favour and run a synthetic oil. I use Mobil 1 (no sponsorship!) and change the oil every 5000 km and filter every 10,000.

The 16 Valve engines have a tendency at high RPM to top up the head with oil - on the earlier engines this can result in oil getting into the intake manifold via the cam cover breather and turning the motor into a 2-stroke. Some cars also have oil surge in this state with attendant drop off in oil pressure. I stress that this tends to occur in race applications only. This can still occur with the 'Red Top' motor, despite the external oil drain. Most people solve the problem by fitting an external catch tank with a drain back to the sump, with the intake breather taking suction from this catch tank.

The 20 Valve has very large oil drains and does not suffer from this problem.

Cranks and Engine Modifications

The 4AGEs come with a variety of cranks. The early models had smaller journals compared to the 87.5 onwards engines, however I believe these were all cast iron. The 4AGZE has a cast steel crank, and many racers use these engines (with normal to high compression pistons) as the basis for race motors due to them being a cheap source of a very strong bottom end. Toby Hunt had this to say:

Stock cranks are apparently good for ~9,500rpm (designed for 10,000) and 200hp - rev above that and the crank will break. Formula Atlantic steel cranks good for 12,000+ RPM and 200+ HP.

From what I can figure, 225-230 HP is about the most you can get out of a naturally aspirated 4AGE, however it is very expensive to do. I also believe that around 180 horsepower is easily, reliably and relatively cheaply attainable through minor headwork, cams and better induction/exhaust.

Engine Mounts

Depending on the car, it may be easiest to use the standard 4AGE RWD engine mounts. 3A RWD (AE 85/KE 70) engine mounts are virtually identical and a direct bolt on fit. A 4AGE will directly bolt into a 3A car.

If you need to fabricate custom mounts then just use the block bosses that best fit the car the engine is going into. Standard RWD set up uses 4 bosses around the oil filter, and 3 on the intake side in a similar location.

Alternator Mount

The RWD alternator mount locates the unit low on the intake side of the engine, which may be of use if the FWD location is inconvenient, however this is in the way of the supercharger. The FWD 4A SOHC, and 4AF/FE narrow angle, single cam gear engine (and possibly the NA MR2) mounts the alternator high on the exhaust side.

On 4A-GE AE92 Corolla's (NA) the alternator is mounted high on the intake side of the engine and the A/C and P/S are mounted on the exhaust side lower down.

Exhaust System

All 4AGEs, including the 20 Valve, have identical exhaust ports. The 20 Valve has 4-2 factory tubular extractors, the remainder have 4-2 cast manifolds. The 20 Valve head manifold bolts at the extreme ends are in a slightly different location to the 16 Valve engines, however the 16 Valve manifolds can be made to fit quite easily.

The standard RWD manifold is a wise option, if it will fit in the car, as by all accounts there is little to be gained by replacing it with a set of aftermarket tubular exhaust headers, however there is much to be gained by going to a larger diameter exhaust system from this point back.

The standard RWD system has 28" long secondaries between the manifold and the tail pipe junction. The TRD RWD exhaust system utilises the original cast manifold and then breaks into 42 mm diameter secondaries that are 485mm to the junction, followed by a 330 mm long 50mm diameter pipe to the muffler, a 640 long section containing the muffler, and finally a 520 mm long megaphone expanding out to 57 mm diameter.

Local tubular headers I have seen are 4-1 design and have either 1 " or 1 5/8" diameter primaries, with a 2" tailpipe. The headers are not very precise - the RWD primary lengths range from 21-28", the FWD from 12-14". I have been told that 2.5" exhaust systems on 4AGEs are very loud, and that 2.25" is a better diameter to go with.

Best I can figure (from a graph I got sent) the ideal is about 28" primaries on 4-1 headers for a 4AGE. The set I am building for my 4AGZE powered Ford 105E Anglia (1964 car) will be 4-2-1, with 14 inch long 1 3/8" primaries, 28 " long 1 7/8" secondaries, and 2.25" tailpipe. This is based on the best I can figure it out, and what I can get to fit. I am building them from preformed mandrel bends, which will be welded together, hence I have a very accurate means of establishing the lengths. The primaries and secondaries should be within a couple of mm in length to each other. I hope to get them built in the next month or so - I have designed them (only took about 40 sketches, drawings and a couple of weeks of measuring and thinking to do!), now I have to make them.

Personally I would not bother with a custom set of headers, especially in what is basically a road car, however the Anglia is too tight for anything off the shelf to fit. Also if you do not have the factory manifolds, an off the shelf set of headers, whilst they may not be ideal, will still work well, and provide a cost effective solution.

Cooling System

The 4AGE comes stock in RWD with a 5.6 litre cooling system. As stated above, the use of an oil cooler in later engines may enable a smaller radiator to be used, due to the amount of cooling done by the oil as a result of the oil cooled pistons. Note that all 4AGEs use the thermostat to let cold water into the engine (as opposed to letting the hot water out), hence the thermostat side of the plumbing should be connected to the bottom radiator tank.

In this manner when the water in the head heats up, the thermostat will open and let cool water (from the radiator bottom tank) into the engine. Hot water leaves the engine and returns to the top radiator tank. All engines have a thermostat bypass so that when the thermostat is shut the water will still circulate 9due to the water pump) around the engine, eliminating hot spots from the water not moving, and preventing the water pump from cavitating.

The 16 Valve 4AGE RWD thermostat and water pump plumbing set up is the simplest to use in RWD configuration, and has both supply and return on the RH (intake) side of the engine. If your radiator inlet (the top header tank connection) is on the LHS of the radiator then a FWD 4AGE top radiator hose can be used, as it goes across the front of the engine, and with a little modification should connect into the radiator inlet.

Any FWD engine (except the 20 Valve or supercharged motors) will fit this plumbing, which is the easiest way of adapting a later engine to RWD configuration. You must use the RWD water pump if you wish to use an engine driven radiator fan, otherwise the water pump bearings will fail.

All 16 Valve engines have a sensor block at the back of the head which contains 2 water temperature sensors and the take off for the heater. On FWD cars and MR2s this unit protrudes out the back of the engine, adding several inches once hoses are attached, whilst on RWD the unit runs across the back of the head and is much more compact, and only adds about 1 inch to the length of the head. The heater hose lies flat against the back of the head as opposed to exiting directly backwards on the FWD engines. These units are interchangeable between all 16 Valve engines, including supercharged models.

The RWD water pump and thermostat plumbing will not fit on supercharged motors as the supercharger is in the way. The best approach here is to utilise the standard remote thermostat assembly (normally mounted on top of the transaxle) and mount it either on the side of the engine or on the inner guard of the car, with custom pipe work/flexible hoses to suit.

The 20 Valve motor has a completely different head, with a large sensor and thermostat block at the back of the head. This also has the supply and return to the heater, and once heater hoses are connected protrudes several inches behind the head. Coupled with the distributor which is driven off the back of the exhaust cam, installation in a normal RWD car may best be achieved by either locating the engine further forward in the engine bay, if possible, or recessing the firewall as required.

Both radiator inlet and outlet face the LHS of the 20 Valve engine, ie exhaust side. The outlet to the radiator is immediately behind #4 exhaust port. The easiest way to mate the radiator plumbing up in RWD configuration on the 20 Valve is to fabricate a pipe that runs from the water outlet forwards over the top of the exhaust manifold. The pipe needs to be roughly hockey stick shaped in plan view, and can be secured to the head outlet flange at the rear LHS of the head, and to the lifting eye bolts at the front LHS of the head. Inlet plumbing needs to run from the radiator bottom tank, along the bottom of the engine, and then up to the inlet at the thermostat housing at the back of the head.

If you are fabricating your own cooling lines be careful to ensure there are no air locks in the system otherwise you will cook your motor.

Intake Manifolds

With the exception of the RWD AE86 4AGE, all engines are configured with the intake manifold air inlet facing the rear of the car. Once again the RWD set up is the ideal one to use, as the open end is towards the front of the car. On 83.5 - 87.5 models (Blue and Black Tops) this is not a problem as the RWD manifold will directly bolt in place.

Later 16 Valve models (87.5 - 89.5 Red and Black Top, or post 89.6 Red Top engines) all face backwards, however it is my understanding that intake manifolds are interchangeable between all TVIS engines (ie up to 89.6 when the Red Top was introduced).

If you do not have access to a RWD manifold, or you have a post 89.6 Red Top, then there are two possible options short of fabricating your own manifold or going to carburettors - cut both ends off the manifold and swap the throttle body to the front of the manifold and blank the rear, or else cut the intake runners and weld the entire top half of the RWD intake on - assuming the intake runners line up.

If bonnet clearance is a problem the 16 Valve manifolds can be shortened by cutting a section out of the vertical part of the intake runners and welding back together - my original engine was shortened 30 mm in this manner. There was no apparent loss in power. Be warned that this will place the cam cover breather almost horizontal and hence a catch tank is an even wiser idea. This means that realistically the oil filler cap and plug leads are the limiting factor for bonnet clearance on 16 Valve motors.

If the engine runs a MAP (Manifold Air Pressure) sensor air measurement system then you can literally fit an air filter directly on the end of the throttle body - some K&N filters fit perfectly, however a cold air induction system may be desirable. If the engine is AFM (Air Flow Meter) then you will need to connect this to the throttle body via a suitable tube. 20 Valve engines run an airbox that a length of UK MK 2 Ford Escort heater ducting fits nicely onto both the airbox and AFM. A side-draught carburettor (ie Weber DCOE) type air filter can be adapted to fit the AFM with a modified base plate. Alternatively the MR2s have a neat adapter that bolts on to the inlet side of the AFM that a round air filter will fit on to.

The 20 Valve airbox also has the inlet to the rear of the engine, however both it and the trumpets it contains can be bolted on upside down, which will place the inlet at the front. Unfortunately this looks less attractive and requires even more height. The airbox can also be shortened however it is made of several layers of thin plate and is difficult to weld - stainless steel welding rod works best. The plastic trumpets can be cut and glued shorter also, however some compromise of smooth internal walls is made. In reality fabricating an entire airbox would not be a complex operation, and some side-draught carburettor trumpets are a close match.

Throttle Linkages

If a standard cable cannot be made to work, or you do not have one, brake cables and fittings off bicycles provide an excellent and cost effective source of components. Mountain bike cables tend to be heavier duty and Teflon lined. Go to a good bike shop and order stainless steel brake cables - galvanised cables will rust up and break off . If you have the room, run a dual system (two cables instead of one) Much easier to get home with a broken cable that way.

EFI Fuel System

If you run the EFI system then you will need a high pressure (~80 PSI) fuel pump. The minimum required is a supply line and a return to the tank. Either an internal (in fuel tank) pump as originally fitted, or an external pump can be used. If you don't want to buy new or aftermarket, external fuel pumps from Nissan 3litre straight 6 cylinder engines have proven effective.

The fuel supply must be at a constant pressure so it may be wise to use a surge tank or use an internal baffle in the tank around the pump pick-up. It is most important to use the correct diameter fuel lines - the supply needs to be at least 5/16" and the return " diameter, otherwise fuel starvation will occur.

EFI Wiring

If you decide to run the factory EFI system then it is best to get the relevant factory wiring diagram and as much of the original wiring loom and sensors as possible. The standard set up has 3 plugs in the ECU - two go directly to the engine, the other goes to the car to such things as power feeds, instruments, warning lights and sensors etc that are not on the engine.

This 3rd plug is much the same for all EFI engines in a particular model car, i.e. 20 Valve vs. 4AGZE vs. 4AFE in the AE 101. As the car side of the wiring diagrams are very much the same, if you cannot get the exact wiring diagram for the engine, you should be able to figure it out from the standard car. The code for the plug pins is written on the circuit board near the plugs, inside the ECU - except for Japanese model 4AGZE ECUs, which do not seem to have any labelling. If you have one with the pin-outs, please let me know!

If you want to run a 'check engine' warning light (which is also the means of displaying diagnostic codes) then you must run a speed sensor, which is normally part of the speedometer. If you do not run this sensor you will get an intermittent trouble warning on the check engine light, however the engine performance is not affected. Unfortunately if you fit the speed sensor it will limit the car to approximately 180 kph top speed. If you do not have the original speedometer a magnet bonded to the drive shaft and a reed switch connecting the ECU to earth works. Note that the US ECU's don't have speed limiters.

Depending on the regulations concerning emissions etc, it is possible to run the engines without the exhaust sensor without any effect on the engine's performance. The lack of an exhaust oxygen sensor will register as a trouble code but will not trigger the check engine warning light. 1989-on ECU's for the US Corolla have two oxygen sensors - one directly before the cat and one after. This may only be in California, though.

It is wise to utilise the 'circuit open' relay system, which shuts down the fuel pump if the ignition circuit is on but the engine is not running (as may happen after an accident). If this part of the wiring is missing in a MAP sensor car then a system connected to the oil pressure switch is just as effective, however a bypass for starting should be fitted. This is triggered from the 'start' position on the ignition switch. A car with an AFM has a fuel pump switch built into the AFM unit itself, which shuts down the pump when there is no airflow.


There are two RWD 5 speed gearboxes that will fit any 4AGE. These are called the K-50 and T-50. There are also 4 speed versions of the same gearboxes called the K-40 and T-40 fitted to other Toyotas, however these are rare. The 4 and 5 speed gearboxes are externally identical. Apparently the K-40 is only fitted to K series engines, whilst the T-40 is almost non-existent, however I managed to find one in a 2TG fitted Corolla. Check the number of gear lever positions - 5 or 6 (i.e. don't forget reverse!).

The K-50 has an integral bellhousing, utilises a cable clutch, and comprises two main alloy sections - front casting with bellhousing, and tail housing. There is also a pressed steel plate that bolts to the bottom of the front section. The T-50 has a separate bellhousing, uses a hydraulic clutch and comprises 4 main alloy castings - bellhousing, two diagonally split front gear casings, and a tail housing. This gearbox is often referred to as the 'split case' alloy 5 speed, and weighs 29 kg.

The K-50 is normally found behind 3A 1500 cc SOHC engines fitted to KE 70 series Corollas and AE 85 Corollas etc. The T-50/4A compatible bellhousing is fitted only to the RWD 4AGE and some 3A engines. The T-50 bellhousing has letters cast into the top section between the uppermost bellhousing to engine block bolt bosses that identify the engine it came from - 3A or 4AG etc.

In either case ensure you get the corresponding bell housing front cover plate (that bolts to the back of the block ahead of the flywheel), and the 2 cast stays that bolt between the bottom of the block and the lower portion of the bellhousing. Apparently the rear crankshaft bearings can flog out if these are omitted.

T-50 Options

The T-50 gearbox was fitted to other engines as well, such as 1S, 2S, 2T, 3T etc. The gearbox itself is visually identical, however the bellhousings differ to suit the parent engine, and the tailshaft housings vary. There are two types of T-50 gearbox - referred to as 20 and 22 spline. This relates to the number of splines on the gearbox output shaft. They both have the same number of splines on the input shaft. There is also a difference in the diameter of the input shaft bearing, which is covered by the bellhousing - 62 mm vs. 68 mm. I ass-u-me the 68 mm bearing is the 22 spline gearbox. The 22 spline gearbox is more desirable as it is apparently stronger. It is also what all AE 86 RWD 4AGEs came with.

This means that the ability to swap a bellhousing is dependent upon getting a bellhousing to match the input bearing diameter. This is particularly important if you wish to upgrade from a (say) 2TG engine to a 4AGE, and intend re-using the gearbox. I suspect some 2TG T-50s are 20 spline and others are 22.

The AE 85/86 series T-50 gearboxes are 650 mm from bellhousing to centre of the gearlever mount, however some tailshaft housings fitted to other cars are shorter, possibly allowing relocation of the gearlever with some mixing and matching of components.

In Australia at least, SOHC 4A engine T-50 bell housings have the clutch mechanism on the LHS, whilst 4AGEs have it on the right. I found a 3A T-50 with a LHS clutch slave cylinder recently. I believe all K-50 bellhousings are RHS clutch mechanism - certainly in New Zealand.

Gear Ratios

Although there are close ratio gear sets available for the T-50, most if not all appear to have one set of ratios, irrespective of the engine

T-50 Gearset Options























$US 1500








$US 2100










Some potential sources for T-50 Close ratio gear sets are:

TRD (Toyota Racing Development) Japan

Quaife, England

Housman Autosport, Ontario Canada

Hollinger Engineering, Melbourne Australia

Note: There appears to be a relationship between Quaife and TRD, on T50 parts. It is suspected the TRD gearsets are actually manufactured by Quaife.

Power Handling

As mentioned above, there are two types of T-50 gearbox - 20 and 22 spline output shaft. I believe the 22 spline gearbox is stronger, but I have not been able to confirm this. The 22 spline gearbox is capable of handling 200 horsepower in a Lotus Seven type car i.e. 600 kg almost indefinitely, and there are several behind 170+ horsepower 3TGTE 1800 cc Turbo engines in 1000+ kg cars, however they appear to wear out eventually.

The K-50 will handle the lesser powered 4AGEs in a normal weight car, however the T-50 is recommended. The K-50 really comes into it's own for easy conversion of Starlets and early Corollas with cable clutches to 4AGE. Although the gearlever may require a new hole in the transmission tunnel, it is quite likely the K-50 will bolt to the existing gearbox crossmember, requiring only engine mounts to be fabricated. (Note - the 4AGE will bolt into 3A subframes - and some KE 70 series Corollas came with 3A engines)

I would certainly not recommend putting a K-50 behind a 4AGZE!

Speedo Drives

The standard speedo drive comes directly out of the tailshaft housing. If you have a really tight transmission tunnel then a VDO angle drive can be bought to allow the speedo cable to lie parallel to the gearbox. The FWD transaxle for the supercharged engine has a 90-degree angle drive that may be compatible with the RWD gearbox.

If you change your overall tyre size, or diff ratio, or mate the gearbox to a completely different speedo, then you will need to make a speedo error correction. Thanks to Neil Fraser for this information.

"The gearbox speedo worm drive ratios I know of include 5 x 19, 6 x 20, 6 x 22 etc. (ie 5 starts on the worm gear and 19 teeth on the driven gear). Most speedos are one of the following 637rpk, 675 or 1000 rpk (revs per km). So lets say that to cover 1 km of distance your output shaft at the gearbox will turn how many revs?

Say a tyre diameter of 590mm - Circumference = 22/7 x .59 = 1.854m

Axle revs = 1000/1.854 = 539.37

Output shaft revs = 539.37 x 4.11 = 2216.8284

Say your speedo is 675rpk (should be written on back somewhere) - required speedo cable revs = 2216.83/675 = 3.284, so therefore best ratio is about 6x20 (3.33)

The small gear will have written on it the number of starts on the worm it would be compatible with (ie 5 or 6 ). Using a 5 start gear on a 6 start worm is always terminal. The worm slides off easy enough but requires practically stripping the whole gearbox..."

Clutches and Flywheels

There are 3 basic clutch types, as follows:

Clutch Diameter

Normal Fitment


7 7/8" (200 mm)

Pre 89.5

Normal 4AGE fitment

8 3/8" (212 mm)

Post 89.5

May be fitted to some earlier MR2s
Also fitted to 4/7AFE and 20 Valve.
Largest clutch to fit T-50 Bellhousing.

8 7/8" (224 mm)



Clutches and flywheels are interchangeable between all motors, however they must be changed as a unit - a 212 mm pressure plate will not fit the other flywheels.

The 200 and 212 mm clutches will fit a T-50 gearbox - the splines are the same, and the clutches and flywheels fit inside the bellhousing. The 8" clutch fits the K-50, I am unsure if the 212 mm will. These clutches as fitted to the 4AGE will work with the T-50 release bearing etc. Use a 5/8" clutch master cylinder.

The 224 mm 4AGZE clutch and flywheel assembly will not fit into the T-50 bellhousing, and the 224 mm clutchplate has a larger diameter spline than the T-50 input shaft. I believe that it may be possible to modify the 4AGZE clutch and flywheel assembly to fit the T-50 bellhousing, with careful application of a die grinder and substitution of pressure plate bolts for dome headed cap screws. If you decide to go down this path be very careful to ensure sufficient strength remains to prevent the assembly coming apart at 7500+ rpm and amputating your ankles

Custom built paddle/puck/button clutches may be the answer if you suffer from clutch slippage with standard items. Lightened billet flywheels are also available for the engines.

Spigot Bearing

Any FWD 4AGE will not have a spigot bearing in the back of the crank for the gearbox input shaft to mate with (although the Black Top 20 Valve apparently does have one fitted) - pays to check, and replace if necessary. The standard RWD 4AGE (AE 86) bearing fits all 4AGEs. This bearing MUST NOT be omitted.

If you need to get an old one out, the easiest way I know is to squirt/pack grease in through the centre of the bearing to fill the cavity behind it. This area is reasonably large, so don't be surprised if it seems to take forever to fill up. Then take a close fitting bolt, place it in the centre of the bearing, and hit it with a hammer. The hydraulic pressure will force the old bearing out. Don't forget to use safety glasses etc.

Starter Motor

Easiest option is to use the starter motor that is correct for the gearbox - make sure you buy it when you get the gearbox. Don't forget the flex plate that goes between the back of the engine and the front of the bellhousing too - you will have to remove the flywheel to get it. The 4AGZE starter mootr is incompatible with RWD gearboxes.

Bolts to Mate Engine to Gearbox



Number Off

Diameter (mm)

Thread Length (mm)

Thread Pitch (mm)

Starter Motor





Bellhousing Bottom





Bellhousing Top





Stays to Bellhousing





Stays to Block





The bolts are high tensile and pretty expensive, so I suggest you buy the bare minimum you require. If the exact bolt sizes are not available you may have to buy the next longest bolt and cut to size. Don't forget to use spring washers.


As stated there are 20 and 22 spline T-50s, and there may be 20 spline K-50s (the AE 85 K-50 is 22 spline). Mixing and matching gearboxes/parts may eliminate the need for driveshaft alterations - the 20 spline T-50 behind a TE 71 2TGEU we fitted into a Starlet mated correctly with the existing driveshaft, which was also the correct length

Engine Identification









Cam Box Colours / Lettering Colour

Blue & Black on Silver background

Blue & Black on Silver background

Red & Black (previous motor still in USA)

Red on Silver background

Chrome on Silver background

Black background

Car Model





















Intake port size





4 Throttle

4 Throttle


18 mm

18 mm

20 mm

20 mm

20 mm

20 mm

Conrod Big Ends

40 mm

40 mm

42 mm

42 mm

42 mm

42 mm

Main Bearings

48 mm

48 mm

48 mm

48 mm

48 mm

48 mm

Injection Type

MAP (Japan/UK)

AFM (US/Europe)


MAP (Japan/UK?)

MAP (Japan/UK?)










No of block ribs







Oil Cooled Pistons







Power (kW)

88 @ 6600

88 @ 6600

88 @ 6600

100 @ 7200

120 @ 7400

123 @ 7800

Power (HP)

118 @ 6600

118 @ 6600

125 @ 6600

130 @ 7200

160 @ 7400

165 @ 7800

Torque (kg-m)

14.5 @ 5200

14.5 @ 5200

14.5 @ 5200

15.0 @ 6000

16.5 @ 5400

16.5 @ 5600

Bore x Stroke

81.0 x 77.0

81.0 x 77.0

81.0 x 77.0

81.0 x 77.0

81.0 x 77.0

81.0 x 77.0











Low (USA)





AW is Mk 1 MR2, AE 86 is RWD Corolla GTS/Sprinter Levin/Sprinter Trueno. AE 82, AE 92, AE 101 and AE 111 are FWD only Corollas, Sprinter Truenos, Sprinter Levins, and Marinos etc.

AE 85 is 3A 1500cc SOHC version of AE 86, AE 91 is 4AFE Narrow Angle 16 Valve version of AE 92 etc.

MAP is Manifold Air Pressure sensor air flow measurement, AFM is measurement by Air Flow Meter.

TVIS is a set of butterflies that close off one of the intake valve ports below 4500 rpm to increase air flow and fuel atomisation. They are operated by manifold vacuum. Engines without TVIS (ie post 89.5 red Tops) have smaller intake ports.

All 4AGEs have the same exhaust ports and manifolds are basically interchangeable, but intake port design and size differ.

Red Top 4AGEs have an external oil drain at the back of the intake side.

4AGZEs and all post 89.5 4AGEs have a stronger block with 7 external ribs, bigger bearings and oil cooled pistons via jets that point up the bores.

Twin coil 4AGZEs have a crank angle sensor in the normal distributor location.

Inlet cam timing changes by approximately 15 degrees at 4500 rpm on 20 Valve engines.

There is reputed to be a supercharged 20 Valve (AE 111 car) but I am unable to confirm this.

The 100 kW 16 Valve, and 20 Valves all have a knock sensor, so it may be possible to run these engines on low octane fuel, however given the high compression of these engines, it is best to run high octane fuel so the best ignition advance profile can be used.


The following table gives the comparative weights of various engines.
Thanks to Trevor Gatland from Hamilton, New Zealand for this information.




4AGE 20 Valve 1.6 litre & T-50

155 kg

Complete as fitted to car (less exhaust manifold)

T-50 5 speed

29 kg

RWD Gearbox as fitted to some Corollas, Coronas etc

3SGE two litre

92 kg

Head and block complete only - no manifolds, alternator, starter etc

3SGE & T-50

132 kg

Includes Twin 45 DCOE Weber carburettors, intake manifold, alternator,
starter motor, 1S bellhousing and T-50 gearbox - cast iron block

3SGE & T-50

161 kg

Complete assembly on carburettors as fitted to car

Nissan SR 20 two litre

139 kg

Alloy block & head, manifolds, alternator, factory EFI

Nissan 5 speed

44 kg

5 speed gearbox fitted to SR 20 in Nissan 200 ZX etc

Nissan SR 20 & gearbox

183 kg

As fitted to car - sourced from Nissan 200 ZX etc

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