316i to 325i convertion

[miRai]

Hi everyone,
I want to know everything i need to have to make this convertion.
its on a e30 316 coupe.
Do i need to change mouts? The wiring needs replacing?

thanks a lot
bye

[Brianmoooore]

Welcome to the zone!
Briefly, you will need the complete engine, clutch and gearbox, including engine mounts, engine wiring loom and ECU, gear linkage, manifolds, exhaust system, air meter/filter, radiator, radiator lower mount, radiator cowl, header tank, the 'coding' plug for the instrument cluster and propshaft.
You will need to modify the air filter mounting bracket to take the 325 air meter and add mounts for the coolant header tank.
The 325 propshaft will mate up to your existing diff. OK, but is far from an ideal ratio for use with the bigger engine, so ideally you need the 325 diff. as well. This is physically bigger unit than the one you have now, but mates up to your driveshafts OK.
If your existing car is a saloon, there are a few other things that should be attended to as well - the front suspension legs are the weaker 45mm diameter type, front brakes are probably unvented discs, rear brakes are probably drums, and there's no rear anti roll bar.
CHECK OUT THE WIRING WARNING ABOUT PIN 20 OF THE C101 ENGINE LOOM SOCKET.

[jmc330i]

Brian, that needs to be stickied in the engine swap forum.

[jimbom30cab]

Other than that, it's a piece if cake !!

[markus_74]

Welcome to the zone!
Briefly, you will need the complete engine, clutch and gearbox, including engine mounts, engine wiring loom and ECU, gear linkage, manifolds, exhaust system, air meter/filter, radiator, radiator lower mount, radiator cowl, header tank, the 'coding' plug for the instrument cluster and propshaft.
You will need to modify the air filter mounting bracket to take the 325 air meter and add mounts for the coolant header tank.
The 325 propshaft will mate up to your existing diff. OK, but is far from an ideal ratio for use with the bigger engine, so ideally you need the 325 diff. as well. This is physically bigger unit than the one you have now, but mates up to your driveshafts OK.
If your existing car is a saloon, there are a few other things that should be attended to as well - the front suspension legs are the weaker 45mm diameter type, front brakes are probably unvented discs, rear brakes are probably drums, and there's no rear anti roll bar.
CHECK OUT THE WIRING WARNING ABOUT PIN 20 OF THE C101 ENGINE LOOM SOCKET.

sorry to hijack your thread.
I'm also in the process of built 325i to replace my 318i m40.

some question:
do I need to change/replace my propshaft if I use getrag m20 240? or I still can use my old propshaft?

if I buy m20 240 getrag taken from e30 320i, should I still buy additional gearbox linkage to replace it?

and the last does my m40 has same radiator lower mount? or I should replace it? I will use air cond radiator

thank you
markus

[markus_74]

Welcome to the zone!
Briefly, you will need the complete engine, clutch and gearbox, including engine mounts, engine wiring loom and ECU, gear linkage, manifolds, exhaust system, air meter/filter, radiator, radiator lower mount, radiator cowl, header tank, the 'coding' plug for the instrument cluster and propshaft.
You will need to modify the air filter mounting bracket to take the 325 air meter and add mounts for the coolant header tank.
The 325 propshaft will mate up to your existing diff. OK, but is far from an ideal ratio for use with the bigger engine, so ideally you need the 325 diff. as well. This is physically bigger unit than the one you have now, but mates up to your driveshafts OK.
If your existing car is a saloon, there are a few other things that should be attended to as well - the front suspension legs are the weaker 45mm diameter type, front brakes are probably unvented discs, rear brakes are probably drums, and there's no rear anti roll bar.
CHECK OUT THE WIRING WARNING ABOUT PIN 20 OF THE C101 ENGINE LOOM SOCKET.

sorry to hijack your thread.
I'm also in the process of built 325i to replace my 318i m40.

some question:
do I need to change/replace my propshaft if I use getrag m20 240? or I still can use my old propshaft?

if I buy m20 240 getrag taken from e30 320i, should I still buy additional gearbox linkage to replace it?

and the last does my m40 has same radiator lower mount? or I should replace it? I will use air cond radiator

thank you
markus

[markus_74]

Welcome to the zone!
Briefly, you will need the complete engine, clutch and gearbox, including engine mounts, engine wiring loom and ECU, gear linkage, manifolds, exhaust system, air meter/filter, radiator, radiator lower mount, radiator cowl, header tank, the 'coding' plug for the instrument cluster and propshaft.
You will need to modify the air filter mounting bracket to take the 325 air meter and add mounts for the coolant header tank.
The 325 propshaft will mate up to your existing diff. OK, but is far from an ideal ratio for use with the bigger engine, so ideally you need the 325 diff. as well. This is physically bigger unit than the one you have now, but mates up to your driveshafts OK.
If your existing car is a saloon, there are a few other things that should be attended to as well - the front suspension legs are the weaker 45mm diameter type, front brakes are probably unvented discs, rear brakes are probably drums, and there's no rear anti roll bar.
CHECK OUT THE WIRING WARNING ABOUT PIN 20 OF THE C101 ENGINE LOOM SOCKET.

sorry to hijack your thread.
I'm also in the process of built 325i to replace my 318i m40.

some question:
do I need to change/replace my propshaft if I use getrag m20 240? or I still can use my old propshaft?

if I buy m20 240 getrag taken from e30 320i, should I still buy additional gearbox linkage to replace it?

and the last does my m40 has same radiator lower mount? or I should replace it? I will use air cond radiator

thank you
markus

[jmc330i]

Welcome to the zone!
Briefly, you will need the complete engine, clutch and gearbox, including engine mounts, engine wiring loom and ECU, gear linkage, manifolds, exhaust system, air meter/filter, radiator, radiator lower mount, radiator cowl, header tank, the 'coding' plug for the instrument cluster and propshaft.
You will need to modify the air filter mounting bracket to take the 325 air meter and add mounts for the coolant header tank.
The 325 propshaft will mate up to your existing diff. OK, but is far from an ideal ratio for use with the bigger engine, so ideally you need the 325 diff. as well. This is physically bigger unit than the one you have now, but mates up to your driveshafts OK.
If your existing car is a saloon, there are a few other things that should be attended to as well - the front suspension legs are the weaker 45mm diameter type, front brakes are probably unvented discs, rear brakes are probably drums, and there's no rear anti roll bar.
CHECK OUT THE WIRING WARNING ABOUT PIN 20 OF THE C101 ENGINE LOOM SOCKET.

sorry to hijack your thread.
I'm also in the process of built 325i to replace my 318i m40.

some question:
do I need to change/replace my propshaft if I use getrag m20 240? or I still can use my old propshaft?

if I buy m20 240 getrag taken from e30 320i, should I still buy additional gearbox linkage to replace it?

and the last does my m40 has same radiator lower mount? or I should replace it? I will use air cond radiator

thank you
markus

The propshaft and gear linkage needs to match the gearbox used, so if you use a 240 getrag from a 320i you will need the propshaft and gear linkage from the 320i as well.

You will need to change the radiator mount as the M20 radiator is wider than the M40 radiator.