M20 Q's

[Old-Skool-Kid]

So my car used to be a M10 318i, but the PO swapped an M20 into it (I was told out of a 90 I think) supposedly re-built it, and did a MAF conversion. I was also told its set up for a turbo. Now I have several questions, some I cant remember right now, but I am unable to find them in searching. So

• Is there a way to tell which M20 I have (year, displacement, etc)
• What parts are/are not interchangeable between years and displacements
• Also, what are the BEST tune-up parts? like oil filter, oil type (and capacity), plugs, wires, etc
• Type of coolant*

I ask about the coolant because the older Range Rovers I work on with the BMW 4.4 in them use blue G48 coolant, and I didnt know if these use any special kind of coolant or just the good ole green stuff.

I appreciate any knowledge bestowed upon me! Thanks guys

[devon.818]

1990 would be 2.5 so m20b25. how high does it rev? if the tach says 7k and you can go over 5k you have the 2.5

its all interchangeable, just some stuff benefits, other stuff makes it worse.


timing belt before anything, then oil change, plugs wires, coolant flush if nescessary, and check vac lines.

post pics and we can tell you what you have, a MAF is pretty easy to spot, its round, where as the AFM(stock) is a retarded ass box.

bmw coolant is best, but you have to mix yourself. just get the 50/50 shit.

[F34R]

Is there a way to tell which M20 I have (year, displacement, etc)

On the side of the head for a *885 number

http://rarefolk.com/bmw/images/320%20m20%20spr%20eta%20885%20cast%20mark.JPG

Then the BEST way to find out is just look for what kind of ICV it has. a B27(eta) ICV is over top the valve cover. On a B25 it is by the AMF connected to the intake boot.

What parts are/are not interchangeable between years and displacements

B27 bottom end can become a B27i stroker(wanna-b) with the intake mani & boot, Throttle body, harness, ECU and a 885 b25 head. So pretty much everything but the b25 bottom end lol

B25 would only need a B27 bottom end.

Then the SETA B27 motor has larger pistons to make a true 2.8 stroker. Same steps are taken with the B27i setup.

That is about it for the motor

Read up:

http://www.r3vlimited.com/board/showthread.php?t=100939

Also, what are the BEST tune-up parts? like oil filter, oil type (and capacity), plugs, wires, etc

Tune-up - anything related to maintaining the car
Filter - Fram
Oil - Mobil1
Plugs - Bosch
Wires - Bavauto Hi-performance

[MR 325]

Here's the OP's engine bay:

http://www.r3vlimited.com/board/attachment.php?attachmentid=49540&d=1323320279

It's definitely running the i wiring, sensors, and ICV. It's got the i intake manifold and throttle body but it's got the e valve cover. Most likely it's a 2.5 with the wrong valve cover but one will not know for sure without checking the numbers as suggested above.

As far as tune up stuff, I prefer Bosch Super for spark plugs and Bosch cap/rotor. For oil most prefer the Mahle or Mann filters but I use Fram sometimes as well. You should definitely use 20w50 oil. I prefer non synthetic, just standard dino oil. (Valvoline or Castrol). For coolant you can run whatever you like. Many prefer OEM BMW coolant but it's not a must.

[MR 325]

Oil capacity is 5 quarts with a cooler, 4.5 without.

[reelizmpro]

There's some mismatched parts on that engine so chances are it's not just a 1990 M20B25. What does the head casting say in between cylinder 1 and 2 plug wires? "Set up for turbo" typically just means it's an ETA with an i head, which might explain the ETA valve cover and brace.

[Old-Skool-Kid]

The only number I can see is "15" between the front two intake ports. and the block has "2.7" stamped on it.

Here are a couple more pics of the engine bay

And thanks guys for the info. Its running like ass right now especially when cold. Tune-up as well as adjusting the valves is going to be done this weekend.

[Old-Skool-Kid]

Please Help!

Instead of starting a new thread, I figured I would continue this one.

Upon replacing the timing belt: The nut on the crank on mine is 1 1/16in, not the 22mm as I have read, which I thought was odd. Now the instructions say "Although it might look that damper is held in place by the crank nut, it is not." but I could not get it to come off with the six bolts removed so I decided to put a puller on it, and COULD NOT get it to move, and I broke it. Im currently screwed because NOBODY has or can get one of these except the dealer and they want $260 + $50 ship and I have to wait 2 weeks to freight it from germany! Does anyone have one I can buy I need it ASAP

[Keith M]

Hit up your regional forum or go to a pick and pull to find another pulley. Not sure why yours didn't come off. Is there a washer between the crank nut and the pulley?

[Old-Skool-Kid]

Im not sure, It doesnt really look like it. Heres a close up:

I hit up the local pick a part yesterday, they have an 87 thats been there for like a week but it was picked clean. Only thing left was the body, steering rack and steering coulmn.

[Old-Skool-Kid]

Would this work? http://www.ebay.com/itm/HARMONIC-BAL...item563deb84bb

But mine Has teeth around it for the CKP, and this one doesnt?