Which M52 is it?

[BONNARSKI]

I was out at the breakers as usual when i noticed an engine lying on the ground under some carpet and it was the sump that caught my eye. When i removed the carpet it was a complete M52 with manual box.
I looked all over the engine and found a few codes like on the rear face of the head, by the bulkhead, it said M52 on a bit of paper and some german stuff. Under the paper was BYA 61066 etched into the head and below that had the dates which nade it a 1997. On the inlet side of the block under the inlet it had BMW 1748450 and on different parts the year.
My question is is there another proper engine code like on the old M20's? I typed everthing i had into google but go noting back.
Going by the throttle body it might be a 2.8 as it has the double butterfly's inside. I haven't done much research into M52's so maybe the 2.3/2.5 have the same TB.
Any help welcome then me tap the piggy bank lol

[Dave_M3]

Was it single or double vanos or were there three bolts on each branch of the manifolds or four

Sounds like a late 528 M52tu engine which isn't really any good to us but then it being a 97 should mean its a M52b28 (the one you want)

[BONNARSKI]

It was single vanos on the inlet cam if iirc and the exhaust flanges have 3 bolts on each. I take it you mean where the mani bolts to the centre section and not the head?
Mite get a run out again tomorrow so will see what i find out between now and then.

[Dave_M3]

If it's single vanos, then it'll be an M52. You'll find out if it's a 2.8 or 2.5 by going off the number on the ECU.

No, I meant the bolts on the head. The M52tu and M54 engines have three studs on each flange at the head whereas the M50 and M52 that's useful to us has 4 on each.

They all have 3 bolts on the bottom of the down-pipes. The M52 engine doesn't have. Double butterfly though... You sure there was two butterflys in it rather than just a double linkage on the outside of the TB?

[BONNARSKI]

Got it sorted, 2.5 M52. Don't know whether to buy or not, think it be worth buyin just for the manual box maybe if it's not too expensive.

[Dave_M3]

Only a Getrag box the same as a 325 etc so not worth a huge amount really.
Even 328/M3 ZF boxes which are better and stronger are only worth about 100-200 euro these days.

Your probably better off just getting a M50b25 or holding out for an M52b28 rather than buying it in my opinion. The 323 engines aren't bad if they have the M50 inlet, re-map, BBTB etc as a friend had one with those few things and it was a nice bit quicker than a 325 but if your going to the trouble its pretty much false economy if you don't start with a 2.8

[BONNARSKI]

Was thinking that lad, thanks.

Why is the M50 more popular than the M52? The troublesome vanos?

[Dave_M3]

No, the M50 is just cheaper. vanos is the same on both engines.

Some people get scared of the all alloy engine and some nikasil bores but any suspect engine will be long dead at this stage.

[BONNARSKI]

Starting this thread up again as plans for a turbo'd M42 seem to not be giving the results i planned so will be going with the M52.

I remember somewhere that on some of these engines you need the ECU, key etc to match the engine. This true or will the ECU from another M52 run it mint? I don't have the money for stand alone management before anybody suggests it, i'd love to but can't right now.

[Dave_M3]

Yes, all M52s need the matching ECU, EWS modules and key (or more so the chip from the key)

You can get an ECU re-flashed and re-mapped in the one go to get rid of the EWS and get another 40bhp though.


Talks of going standalone on an M52 seems abit daft to me to be honest. Unless your supercharging it or something I couldn't see any gains from it and even at that the Siemens ECU would be perfectly capable of running a charger.