1979 320/6 from Portugal (swap m20b25)

[Moutinho]

Hi everyone, I'm here to present my 03/1979 BMW E21 320/6 with a 5-speed overdrive transmission. It all started with cleaning the carpet, when I noticed that the driver's side floor was in bad shape and had some holes. After disassembling the interior, one thing led to another... I started by cleaning the engine, but realized something was wrong, my head gasket was blown. I started to renovate the M20B20, but then an offer for an M20B25 came up and I didn't hesitate to take it.the car is currently undergoing floor restoration. In the meantime, I started the engine swap, aiming to reach 200hp. To achieve this, I've gathered the following parts:
- Larger Bosch O280 155 710 injectors
- 278º Cam
- Forged rocker arms
- Kdify M20 programmable ECU
- wasted spark with Bosch ignition Coil 0 221 503 002
- Lambda wideband Bosch
- M20b20 flywheel
- Shmiedmann exhaust manifolds and stainless steel exhaust

I've already done a brake upgrade; I used some Lockheed AP 4-piston callipers in the front with the original 323i discs, in the rear I adapted some brake calipers from a 2005 Renault Megane. Regarding the suspension, I have some BC Racing coilovers to install and polyurethane bushings for the whole car. Got a new 3.65 188mm LSD.

Right now I'm trying to understand some things that I still don't know how to solve.
- Fuel system, what to do with the fuel pump, put it external or in the tank?
- Do I use the water pump from the 1st gen or the 2nd gen?
- Which silicone tubing should I buy, 1st gen E30 or 2nd gen E30?
- Do I use the starter motor from the M20B20 or the M20B25?
- The car has a phase 1 front end, I wanted to upgrade the radiator, but I can't find any radiator that isn't for the 2nd gen front end.

I'm just a curious guy who likes mechanics, but I'm not a mechanic, not even close. I'll have some difficulty with the electronics part, but little by little the project will come together.

[nic65]

Ciao e benvenuto...
progetto interessante, seguo con interesse

[Jeroen]

Welcome back Sir! Interesting project, but I must leave the advice to others, no expert when it comes to the differences combined with fitment in an E21. But, keep us posted!

[uwbuurman]

- fuelpump, I suggest the 323i setup, so underneath the car. Need the 323i fuelsender/pickup aswell, in the tank. Swap it for de 320/6 one
- type 1 WaPu is not for a visco fan. An e21 type 1 has a electric fan. So either you use an electric fan, them type 1 WaPu, or you use the visco fan, hence the need for a type 2 WaPu. If possible, I would use the electric fan, since visco is not to reliable and it costs about a handfull of horsepower
- e30 type 1 hoses will mostly fit, but the radiatorhoses will be a bit of a hassle, just use e21 323i hoses instead.
- m20b25 starter. Is bigger, fits anyway, more crank.
- invest a bit more and get a custom build aluminium rad. to fit the type 1 front.

[nic65]

e montare i caburatori singoli per ogni cilindro per mantenere tutto in linea con gli anni della vettura?