Tech:Engine/A Series/Converting to RWD

From Rollaclub
Jump to: navigation, search

Converting A-Series engines to RWD can be done.

List of things that you might want to consider when installing a 4AGE based engine into an KE70/AE71/AE86.

Engine/Gearbox Crossmembers;

Engine Crossmember - You can use the engine crossmember from an AE71/AE86 as the engine mounts will bolt straight up. If you have a KE70 crossmember, you will have to get custom engine mounts made (This will require them to be engineered). (See for comparison of KE70 and AE71 crossmembers).

Gearbox Crossmember - You can use the gearbox crossmember from an AE71/AE86 as the gearbox mount will bolt straight up. If you have a KE70 crossmember you will have to re-drill some holes to mount the gearbox.

Engine/Gearbox Mounts;

You can use the engine/gearbox mounts from an AE71/AE86 4A-C engine or have some custom made. (Custom made engine/gearbox mounts will require engineering). The rubber mounts can still be bought new from TRD and Cusco.

Flywheel / Clutch / Pressure Plate / Throwout Bearing;

There are 2 different size 4AGE flywheels, for 200mm and 212mm clutches (Sometimes the 212mm clutch is referred to as 215mm). If yours is the 200mm clutch, just buy an AE71/AE86 200mm clutch kit. If yours is the 212mm Clutch, you will have to buy an AE92 100KW 4AGE 212mm clutch kit (also you will have to buy a throwout bearing from an AE71/AE86, as the AE92 clutch kit throwout bearing is completely different). Apparently the 212mm clutch will get better grip as it has more surface area.

Spigot/Pilot Bearing;

FF / MR mount 4AGE engines do not have a spigot bearing in the crankshaft. You can press a spigot bearing from an AE71/AE86 4A-C into the crankshaft. Part number for the Spigot/Pilot bearing is 6001 from most bearing shops.


There are 2 main options for a gearbox. The standard T50 is good for N/A and some low power Boosted setups, Though if you are chasing high power you will want to go with a W5x series gearbox.

T50 Gearbox - You can source a T50 gearbox from an australian AE71/AE86 or get one from an imported AE86. There is 1 main difference between the australian and japanese T50 gearboxes. Both of these should handle stock power without a problem.

ADM T50 (Australian Domestic Market) - Clutch fork on passenger side of car.


JDM T50 (Japanese Domestic Market) - Clutch fork on drivers side of car.


W5x Gearbox - You can use a W55 gearbox with a bellhousing adapter, people usually swap to these when their engines are putting out high power figures as T50 gearboxes are a lot weaker. Note that you will have to modify your tailshaft to suit the different gearbox output shaft.

4AGE To W Bellhousing.jpg

4AGE To W Bellhousing On.jpg

Clutch Master / Slave Cylinders;

If you install a 4AGE into a KE70, it is easiest to put the pedal box and clutch master cylinder in from an AE71 (as the KE70 came with a cable clutch). With an AE71/AE86 you should already have a clutch pedal and clutch master cylinder (provided its not an automatic gearbox). You can use whatever slave cylinder came with your gearbox, though you may need to get a new single piece clutch line fabricated if you are converting a KE70. (See )


What tailshaft option you take depends on what gearbox you have and what diff you're adapting it to. Some people decide to have a custom 1 piece talshaft made out of their existing tailshaft. Also you may chose to install a tailshaft loop in case the tailshaft decides to let go.

Intake Manifolds;

There are 4 options for your intake, these are also dependant on if your 4AGE is smallport or largeport.

JDM AE86 Intake Manifold - The stock intake manifold that came on the large port blue top 4AGEs can be used if you already have one or are able to source one cheaply. You can use these on a smallport motor but you will need an adapter to go inbetween the manifold and the head.

Cut n Shut Intake Manifold - This is a popular option for converting the FF / MR intake manifolds to a RWD layout. This is probably a better option as they are more common and cheaper to buy. You will have to find someone that can cut the throttle body mount off and swap it onto the opposite side of the intake manifold.

Quad Throttle Bodies - Nothing beats the sounds of quad throttle bodies, its a good way to go if you want a tough N/A engine. These can be found on the 20 valve variant of the 4AGE.

Twin Carbs - Induction sound is to die for, Though you will have to modify your ignition and fuel delivery systems. (I have heard of people converting back to a 3A-C distributor and also modifying other distributers to suit). You will also need to remove the injectors and have the injector bosses in the head welded up or blocked off somehow.

Cooling System;

Radiator - A standard AE86 radiator will have no problems keeping a 4AGE cool. However if a more effective/readily available option is wanted then a 90s model Hyundai excel radiator comes close to fitting. The normal model has a single integral fan while the air conditioned model has dual thermo fans.

Rear Water Outlet - Some rear water outlets will want to brush up against the firewall, an AE82 4AGE rear water outlet is very similar to the JDM AE86 4AGE rear water outlet and should clear any firewall. A 4AGZE rear water outlet will clear the firewall no problems on an AE86.

External Thermostat - If your 4AGE came in a FF or MR layout, you will want to run an external thermostat. This means you will have to cut some of the origional piping, be sure you mount it low so it doesn't get any air locks inside.

Thermo Fan - To keep the radiator cool, install an aftermarket thermo fan, you will also want to fabricate a shroud to direct the air flow across the radiator.

Article by Medicine_Man

Back to A Series Engines

Back to Main Page